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Working on a Ryobi 725R, had alot of issues and after addressing them all I'm stuck on the carburetor adjustment screws.
Can anyone give me any pointers on how I should go about getting the correct settings so that the engine starts?
Right now I'm hearing it pop but it just wont get up and run.
The muffler isn't presently installed.

Depending on type of carb installed the setting could vary from 1 turn out to 2 1/2 turns out. Before continuing I would check compression and make sure you have 90 or more. Below 90 and it is a boat anchor.

ILENGINE said:

Depending on type of carb installed the setting could vary from 1 turn out to 2 1/2 turns out. Before continuing I would check compression and make sure you have 90 or more. Below 90 and it is a boat anchor.

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thanks for the suggestion, I dont have a compression tester so I cant give exact numbers but I can tell its got enough.
I'm about to use it as an anchor so it better start before my arm gives out!

Two strokes are similar to four strokes, in that you need: compression, fuel and spark. For two strokes other factors come in to play. Such as timing (do you have a sheared flywheel key) or an air leak somewhere in the engine.

Since you said you got a pop, I believe your problem may be timing related. Adjusting the high and low needles will have minimal effect until you get it to actually start.

You could even have a compression problem. Get the unit compression tested and go from there. In my experience with two strokes, a reading under 120 psi means too little compression to run.

Rokon said:

Two strokes are similar to four strokes, in that you need: compression, fuel and spark. For two strokes other factors come in to play. Such as timing (do you have a sheared flywheel key) or an air leak somewhere in the engine.

Since you said you got a pop, I believe your problem may be timing related. Adjusting the high and low needles will have minimal effect until you get it to actually start.

You could even have a compression problem. Get the unit compression tested and go from there. In my experience with two strokes, a reading under 120 psi means too little compression to run.

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Thanks for the suggestion, I haven't checked the flywheel for timing. Messing with that trimmer is on my list of things to do today so I'll let you know what happens.

We have some good 2 stroke guys . No one has mentioned crankcase pressure which is required for pushing charge into combustion chamber. Pros have pressure gauges to check this . A pressure gauge is not that expensive if you go bare bones.

Im not a good two stroke guy but here is a few. Pick it up by the starter recoil handle. If it holds then it more than likely has enough compression to start. If the rope all pulls out and the unit is still sitting on the floor then its got some real compression problems. If the compression seems all right then check for spark. If the plug is wet dry it off and clean the fuel out of the cylinder. If its dry put a few drops of gas on it and try to start it. If still no go look for air leaks in the case, carb, fuel lines bulb. Check your muffler for blockage and look the cylinder over from the exhaust. Some times you just have to take your carb off again and start over or get a new carb.

Rokon said:

Two strokes are similar to four strokes, in that you need: compression, fuel and spark. For two strokes other factors come in to play. Such as timing (do you have a sheared flywheel key) or an air leak somewhere in the engine.

Since you said you got a pop, I believe your problem may be timing related. Adjusting the high and low needles will have minimal effect until you get it to actually start.

You could even have a compression problem. Get the unit compression tested and go from there. In my experience with two strokes, a reading under 120 psi means too little compression to run.

Click to expand...

It seems someone else worked on this trimmer before me and in the process they damaged the flywheel. Error on my part was assuming it was alright....anyhow the key slot on this flywheel was non-existent so whoever tried to fix it used a half moon key and forced the flywheel on. Which worked for a short time but as you can see in the picture eventually the space wore down.
Replacing the flywheel is the way to go, but since parts are virtually non existent I think I'll try making a new slot and using a key.

possum said:

Im not a good two stroke guy but here is a few. Pick it up by the starter recoil handle. If it holds then it more than likely has enough compression to start. If the rope all pulls out and the unit is still sitting on the floor then its got some real compression problems. If the compression seems all right then check for spark. If the plug is wet dry it off and clean the fuel out of the cylinder. If its dry put a few drops of gas on it and try to start it. If still no go look for air leaks in the case, carb, fuel lines bulb. Check your muffler for blockage and look the cylinder over from the exhaust. Some times you just have to take your carb off again and start over or get a new carb.

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Thanks for the tip! I'll be adding it to my bag of tricks.

Grassbandit said:

View attachment 24748

It seems someone else worked on this trimmer before me and in the process they damaged the flywheel. Error on my part was assuming it was alright....anyhow the key slot on this flywheel was non-existent so whoever tried to fix it used a half moon key and forced the flywheel on. Which worked for a short time but as you can see in the picture eventually the space wore down.
Replacing the flywheel is the way to go, but since parts are virtually non existent I think I'll try making a new slot and using a key.View attachment 24749

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You cannot make a new slot anywhere in the flywheel, if that's what your above statement means. Timing is critical for 2-strokes to run properly. Even slightly moving the flywheel from it's original mating spot on the crankshaft will advance or retard timing.

If this flywheel slot is truly gone, a replacement flywheel is the only solution.

Rokon said:

You cannot make a new slot anywhere in the flywheel, if that's what your above statement means. Timing is critical for 2-strokes to run properly. Even slightly moving the flywheel from it's original mating spot on the crankshaft will advance or retard timing.

If this flywheel slot is truly gone, a replacement flywheel is the only solution.

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In that case, I wont be able to save this trimmer.
Gonna just keep it as a parts donor unless I find a flywheel by some stroke of luck.

Bandit, Take full pics and post the flywheel details. I have my deceased 790R in a box. They probably changed the casting , etc. If there is a match you can have my flywheel if we can figure out how to get it there for less than the cost of your repair parts. motoman. ( Are you sure you are on a good cost/scrap path? I bought a new Sears 2 stroker for $113 last year.)

motoman said:

Bandit, Take full pics and post the flywheel details. I have my deceased 790R in a box. They probably changed the casting , etc. If there is a match you can have my flywheel if we can figure out how to get it there for less than the cost of your repair parts. motoman. ( Are you sure you are on a good cost/scrap path? I bought a new Sears 2 stroker for $113 last year.)

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Thanks for offering to help. The difference in the currency makes it really expensive....$1 US = $2.70 Local for me. Add customs and shipping to dealer markups and you're almost paying 5x as much as you'd pay stateside. I'm comfortable waiting around for another one to go bust before spending alot of replace the flywheel.
I am not in any pressure to repair it, just nice for me to have older machines working perfectly.

You say in the original post that you did not have the muffler installed. I work on 2 cycle mopeds and cycles in my shop. Two of the very first things I look for if a job comes into my shop not running or running bad is the muffler and air cleaner installed. They just wouldn't run or run very bad with them missing. They need that back pressure to run right. I know what you have isn't a cycle but I will bet they run on the same principle. Some of the people that race 2 cycle bikes will modify the exhaust system to get more power.

reynoldston said:

You say in the original post that you did not have the muffler installed. I work on 2 cycle mopeds and cycles in my shop. Two of the very first things I look for if a job comes into my shop not running or running bad is the muffler and air cleaner installed. They just wouldn't run or run very bad with them missing. They need that back pressure to run right. I know what you have isn't a cycle but I will bet they run on the same principle. Some of the people that race 2 cycle bikes will modify the exhaust system to get more power.

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hmmmm I'm really getting a lesson on this one! Surely I'll be adding your advice to my knowledge base.
Normally I can get trimmers to start without the muffler, especially in situations where they get blocked with carbon. In this particular situation someone else pointed out the flywheel as the culprit since I got the engine to pop and they were indeed correct.

Today the stars are aligned for trivia. I knew more knowledge wouldpour into this thread. Here are a few facts which may surprise about 2 strokes...

An engineer in East Germany (yep , before the wall fell) developed 2 strokers producing over 3 horse power per cubic inch. A hot US V8 produces 1 hp plus.

Two stroke race bikes(500cc = 30 cu inches )about 10 years back produced 200 HP (check me) and were unmagageable on the track because the power hit threw riders off and killed some.

Indeed the exhaust is important as stated. Take a look at 2 stroke motocross bike mufflers. The bulge was slowly developed so the mixture trying to exit is thrown back into the chamber for added power. :thumbsup

PS Grassbandit, Your Ryobi flywheel does look like I remember mine. I have not removed it because of the doubtful cost benefit, right?

motoman said:

Today the stars are aligned for trivia. I knew more knowledge wouldpour into this thread. Here are a few facts which may surprise about 2 strokes...

An engineer in East Germany (yep , before the wall fell) developed 2 strokers producing over 3 horse power per cubic inch. A hot US V8 produces 1 hp plus.

Two stroke race bikes(500cc = 30 cu inches )about 10 years back produced 200 HP (check me) and were unmagageable on the track because the power hit threw riders off and killed some.

Indeed the exhaust is important as stated. Take a look at 2 stroke motocross bike mufflers. The bulge was slowly developed so the mixture trying to exit is thrown back into the chamber for added power. :thumbsup

PS Grassbandit, Your Ryobi flywheel does look like I remember mine. I have not removed it because of the doubtful cost benefit, right?

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Everybody thanks for your pointers and insights.
Motoman PM me and lets hash out the details.

Bandit, Go to youtube where a gentleman shows detail of a flywheel bore/key. It shows the aluminum casting with a cast-in alum key which was a surprise to me. His problem was the key broke off, shifting the timing. Patience, I will try to pull off my old flywheel. Who knows, maybe my Ryobi's "death" as similar. What is your zip?

motoman said:

Bandit, Go to youtube where a gentleman shows detail of a flywheel bore/key. It shows the aluminum casting with a cast-in alum key which was a surprise to me. His problem was the key broke off, shifting the timing. Patience, I will try to pull off my old flywheel. Who knows, maybe my Ryobi's "death" as similar. What is your zip?

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I wonder how or why the key would have broken off?
Perhaps an attempt at removal was incorrect....good luck with getting yours off.

Bandit, Many on the forum might also think that an aluminum key is a strange material selection. Doubt that is aircraft alloy so seems like it is not as good a selection as steel, and much more subject to fatique cracks. I will try to pull mine and report. I would think any used ones require crack checking before using. There was a neat little 2 can test kit available at auto stores a few years back. Use the cleaner, then the penetrant dye and read it under a black light. Who the hell has a black light??? Just sayin...BTW after the youtube photo I looked again at your pic . It kinda looks like "whoever" may have ground off two nubbins adjacent to the key centerline , put a different taper on and then filed a keyway?
If that is so your poor little engine may be trying to start with spark + or - 20 degrees to TDC

motoman said:

Bandit, Many on the forum might also think that an aluminum key is a strange material selection. Doubt that is aircraft alloy so seems like it is not as good a selection as steel, and much more subject to fatique cracks. I will try to pull mine and report. I would think any used ones require crack checking before using. There was a neat little 2 can test kit available at auto stores a few years back. Use the cleaner, then the penetrant dye and read it under a black light. Who the hell has a black light??? Just sayin...BTW after the youtube photo I looked again at your pic . It kinda looks like "whoever" may have ground off two nubbins adjacent to the key centerline , put a different taper on and then filed a keyway?
If that is so your poor little engine may be trying to start with spark + or - 20 degrees to TDC

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you're very right, it's kinda annoying to work on things after someone else would have tampered with it.
I boxed up the parts this evening so my worktable is clear for the next project that comes along. Might even restore another crapsman mower.

Grassbandit said:

I wonder how or why the key would have broken off?
Perhaps an attempt at removal was incorrect....good luck with getting yours off.

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A good backfire on start-up can shear the key.

BTW, the key has to the softest metal between the flywheel and the crank to prevent possible engine damage. Had a mower come in with a steel key (not stock) on a steel crankshaft with an aluminum flywheel. Owner hit something solid with the blade. Mower still ran, but "idled high", according to the owner. Once the top cover came off, the carnage unfolded. The steel key rolled half way and locked. The flywheel was completely fractured from the center out. The high idle was from the engine being advanced due to the grenaded flywheel.

Rokon, Good point on the protection a softer flywheel key might provide. I remember outboard propellers... But hmmm, responders on this thread (as many) diy'ers and pros, and I suspect most pros would never care to repair a $125 trimmer when repair parts quickly reach $75... Anyway, if the lowly trimmers are throwaways why would a mfgr choose to protect with a soft key? Another thought which occured ...the locking power of the "taper." I once read how much friction is achieved with a properly torqed taper fit (as in Morse taper in machine tools). So the disigners are relying mainly on the taper of the alminum bore to hold and the anemic aluminum key is mainly for alignment? I love the way the forum can count the angels on the head of the pin to keep things going in winter!!

Edit, Oh yeah, Bandit's flywheel taper looks hand dressed. Not a chance that would mate with the shaft , thus putting it entirely on the key to hold??

Edit, Looked briefly at penetant inspection kits. Black light (ultraviolet)is very expensive @ around $750. Magnaflux sells a 4 can kit with no black light required for about $90 retail, but with a 5 year shelf. Curious if you professionals use this for e.g., valve seats, heads etc..

Went dumpster diving today and found this Crapsman Trimmer. I know alot of times engines and parts are interchangeable across brand names so I'm hoping that the flywheel on this one will match the Ryobi we've been talking about.
I'll take it apart later and tell you whats up. No plans on restoring! maybe I'll just hang it as an ornament. lol

Below is the flywheel removed from my deceased Ryobi 790R. To remove I just held the flywheel by hand and rapped straight down on the shaft with a small brass hammer. It came right off. Please find relief (and humor?) in the warning words cast into the flywheel..."not to modify for fear of burst hazard." Relief that the 7000 rpm engine did not start with the weak fix Grassbandit inherited at the key/bore. The cast-in aluminum key is visible and the same shown on the youtube...FYI. (Grassbandit, detailed PM sent yesterday)

motoman said:

Below is the flywheel removed from my deceased Ryobi 790R. To remove I just held the flywheel by hand and rapped straight down on the shaft with a small brass hammer. It came right off. Please find relief (and humor?) in the warning words cast into the flywheel..."not to modify for fear of burst hazard." Relief that the 7000 rpm engine did not start with the weak fix Grassbandit inherited at the key/bore. The cast-in aluminum key is visible and the same shown on the youtube...FYI. (Grassbandit, detailed PM sent yesterday)

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Your flywheel has differences, visually speaking. On the left there are two big holes and 1 smaller one. The right side has 6 small holes and 2 large ones around it.
My flywheel only has the larger holes.
Very cool of you to go through taking it off and posting pictures.....and its good to see how the flywheel with built in key is supposed to look.

Do you remember why you put your 790R out to pasture?

Bandit, don't sweat the holes: the 8 hole side is just pinning in the 2 magnet patches, and the 3 on the other side are for the counter balance lump. Nothing functional. You should pop the cowl on your dumpster find and do a visual . If you have a steel rule you could get the ht and dia easily. Maybe they cranked 1000's of these little buggers out. I notice a big read on this thread. Hope those with lots of experience will chime in.:thumbsup:


Edit. The 790 lasted 10 years of abuse . One day it lost a little top end rpm so I looked at it and saw light contact marks on the 2 magnet patches. That made me think the shaft was wobbly. I dug in and the clutch removal was a no starter as the factory had repair-proofed the retaining screw. I ruined the (good) clutch and with the replacement cost of the clutch, gas tank, and ignition module I was at something like $100. So I bought a new half-cousin weedwacker at sears. The Ryobi was not putting out spark at the end. I tested the Sears in parallel and it would jump 1/4" easily. BTW today since I was finally down to the bearing with the removal of the flywheel, I looked for looseness , but none evident. The flywheel bore is perfect so I still don't know why contact.

NFIG]24794[/ATTACH]

The Craftsman trimmer had a flywheel with the exact same numbers and measurements so I got happy! But upon further review....the Inner Diameter where the crankshaft goes through is actually smaller. Totally a let down.
The trimmer was in bad shape from being left outside in salt air and water, but anyways enjoy the pics. If you see something you want let me know.

motoman said:

Rokon, Good point on the protection a softer flywheel key might provide. I remember outboard propellers... But hmmm, responders on this thread (as many) diy'ers and pros, and I suspect most pros would never care to repair a $125 trimmer when repair parts quickly reach $75... Anyway, if the lowly trimmers are throwaways why would a mfgr choose to protect with a soft key? Another thought which occured ...the locking power of the "taper." I once read how much friction is achieved with a properly torqed taper fit (as in Morse taper in machine tools). So the disigners are relying mainly on the taper of the alminum bore to hold and the anemic aluminum key is mainly for alignment? I love the way the forum can count the angels on the head of the pin to keep things going in winter!!

Edit, Oh yeah, Bandit's flywheel taper looks hand dressed. Not a chance that would mate with the shaft , thus putting it entirely on the key to hold??

Edit, Looked briefly at penetant inspection kits. Black light (ultraviolet)is very expensive @ around $750. Magnaflux sells a 4 can kit with no black light required for about $90 retail, but with a 5 year shelf. Curious if you professionals use this for e.g., valve seats, heads etc..

Click to expand...

last bit first.
You can get fluro dye penetrant that are died with flouroscene ( the stuff you use to trace drains ) so you cen see it with the naked eye.
Once the surface has dried out spray it with foot powder or spray on talcum powder this will wick up the die from the cracks & make them easy to see
Next those special plant growing tubes have enough UV to activate the glowing dies in the Magna flux kit.
Third a std UV tube ( you know the ones that mke your undies show through your cloths ) in a std fluro light fitting will also work.
A tanning lamp works really well and you can usually find them in second hand shops.
Only down side of these three is they have a short duration so you either need to turn them on & off a lot or do the inspection while the lights are on.

As for break away keys, even on the cheapest piece of equipment the makers both have to offer a warrantee and take out product liability insurance both of which require the fitting of a safety device like a shear key.

Bandit, Tough it's not a match, but not a surprise . I looked at some online flywheels and there are lots of them which kind of look alike but.. $18-$80 yikes. So check carefully the dimensions I sent. You say go and I will send you a USPS track no. to the address given, no charge, no big deal.

Berts, Good tips. So a good US plumbing store will have the drain tracer? You did not mention if you do crack checking on customer machines??

motoman said:

Bandit, Tough it's not a match, but not a surprise . I looked at some online flywheels and there are lots of them which kind of look alike but.. $18-$80 yikes. So check carefully the dimensions I sent. You say go and I will send you a USPS track no. to the address given, no charge, no big deal.

Berts, Good tips. So a good US plumbing store will have the drain tracer? You did not mention if you do crack checking on customer machines??

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No you will have to buy the dye penetrant spray from a bearing shop or engineering supply store.
The dyes are the same that funny limey yellow or yellowish red but the kit has them dissolved in a very light oil with very high surface tension so it will wick into the cracks & be drawn out by the developer ( spray talc ).
There are two types of dye penetrant test kits, UV or visible light and now I come to think about it, then shop chain named "plumbers suppy" down here keeps the visible light kits .
The dye , sodium or patassium floroscene is bought as a powder. It is a very powerful dye.
To does a dain you put a match in the powder, tap the loose dust off the match then drop it into the water good for several thousand gallons.

Berts, Great to have the pros reveal secrets. Curious if such crack detection is a regular check during rebuilds such as aluminum heads. valve seats, shafts?

No,
did it regularly when I was a metallurgist , but that was another life.
Even went to colledge & got some secondary diplomas in various methods of NDT.
I regularly check used con rods & crankshafts I fit to vintage , veteran & classic motorcycles
Never bothered with mowers as the cost of replacement parts does not warrant it.
I just fit a new part if anything is suspect.
Usually when you strip an engine it will tell you what is happening, all you have to do is look carefully at each part before as & after it comes off.
then degrease the parts properly and look again. look carefully at all the other associated parts
The only part I would bother to do a dye pen check on a mower is the crank.
If I have to spit the cases then the engine will get new rods on both the piston & counterweight as these two parts together is less than the labour cost in disassembly & reassembly.
No customer will kiss my ###### for saying them $ 35 on a $ 350 rebuild.
But all of them will kick the same part of my anatomy, vigeriously should I get it wrong and the rod fails after a $ 325 rebuild.

Blue smokes are dead easy you just pump them up & suck them down.
If I suspect a crack I pump them up in a tub of water, you just have to go to the trouble of making proper blanking off plates for the inlet & exhaust.

Dye penetrant testing will only confirm the surface integretity of a single item.
It will show you the head is cracked around the valve guidebut it won't show you that the head is leaking around the valve guide.
Mower valves are not under enough stress to suffer from stress cracking.
Cracked valve seats will show up when you lap them and again, a leaking seat is not detectable you can only find a physical crack in a single piece.
So you could dye pen check th head after you had installed the seats to verify that you had not cracked the head installing them, but that would be really rare.

Remember we are dealing with very low stressed lazy engines in a very low state of tune.
If you are doing 54Hp 500cc single cylinder motorcycle then things are a bit different.
However a 15 Hp 435cc mower engine is not in the same country let alone the same ball park.

nearly all of the internal engine problems on mowers ( excluding blown head gaskets on inteks ) can be traced back to low / no oil.
After that it is vibration from out of balance blades
followed by fractures caused by hydraulic locks

Again thanks for your comments. Regarding failure mechanisms in ? air cooled lawn related engines. Is "low oil" the same as "heat kills?" You did mention cowling important in thermal design of the rig (reminds me of VW. My measurements and others' experiences show these engines running 280F oil in summer and I have measured 304 F on the head. This is on its way to 380F where the aluminum starts to creep (soften). The intek pushed an exhaust guide which I theorized was softened aluminum losing grip. Whadda ya think?

motoman said:

Again thanks for your comments. Regarding failure mechanisms in ? air cooled lawn related engines. Is "low oil" the same as "heat kills?" You did mention cowling important in thermal design of the rig (reminds me of VW. My measurements and others' experiences show these engines running 280F oil in summer and I have measured 304 F on the head. This is on its way to 380F where the aluminum starts to creep (soften). The intek pushed an exhaust guide which I theorized was softened aluminum losing grip. Whadda ya think?

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I would not think anything untill I saw everything.
Most times guides shift in the head it was due to bad fitting in the first place usually combined with insufficient clearances and possibly overheating to boot.
Valve guides are not under any real stress if the floor is machined nice & square.

Now as for your numbers some where some one has got their units mixed up .
400 deg C is where you should start to worry not 380 F.
This transittion temperature will also vary greatly depending upon the exact alloy being used.
heads are generally Al-Si-Cu-Mg alloys with controlled Fe.
Strictly speaking Fe is an impurity in Al casting alloys as it readily forms Fe-Si which are really hard & brittle.
However scrap Al is cheap & has high Fe content . Fe will form a high strength skin on the surface of the mould so facilitates clean & early stripping so die casters keep it as high as permissible depending upon the actual Si content.

As a home project it is worthwile to do a guide but as a work shop job again not cost effective as the price of a new head is less than the parts & labour to fix the old one.
You will need to rebore , note I said bore not drill , out the old guide hole and get an oversized valve guide you need a .002" to .005" interfearence fit.
This oft requires some lathe work as I have never seen oversized guides.
'The other alternative is to build up the guide hole and bore it out to suit the std guide.
You will see a lot of people recommending some sort of epoxy , Some times you get away with it some times you don't .It is a bit too hot for most epoxies.
You could also try some thing like loctite high temp bearing retainer.
Home owners can get away with these sorts of repairs because if it fails, tough luck but not the same if you are taking some ones hard earned so it is a new head for me.

Inteks have a big design flaw in that the bridge between the pushrod chamber & the cylinder is too thin for the position of the head bolts.
It really needs another one in the middle of this section or a lot more metal.

When the Intek came apart I spent some time reviewing online data. The 380F figure came up repeatedly as creep temp. Also there was not a problem with the fit dimensions of the guide /bore based upon .001-.002" fit. The guide was removed , measured, and refitted only to move again. Briggs does not sell replacement guides forthe Intek V 24, only complete head assemblies. Aftermarket fans are popular for AC bikes like Harley whose rear cyl is prone to overheat in slow moving traffic. I looked for locktite able to withstand head temps and could not find any.

motoman said:

When the Intek came apart I spent some time reviewing online data. The 380F figure came up repeatedly as creep temp. Also there was not a problem with the fit dimensions of the guide /bore based upon .001-.002" fit. The guide was removed , measured, and refitted only to move again. Briggs does not sell replacement guides forthe Intek V 24, only complete head assemblies. Aftermarket fans are popular for AC bikes like Harley whose rear cyl is prone to overheat in slow moving traffic. I looked for locktite able to withstand head temps and could not find any.

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That is the big trouble with Dr Google.
Some one makes a mistake.
22,000 people who have absolutely no idea repost the item with the mistake in it because they think it makes them look good on the web and google picks up the garbage because it works basically on the force of numbers.
Remember that old joke from prep school " eat S..T 40,000,000 flies can't all be wrong"

The Aluminium Developement council has an excellent web site which lists the bulk properties of most commercial alloys .
But insead of giving information from known expert domains top priority Google goes for paid positions then numbers so counts the repostings higher than the experts.

Now as for your guide.
every time you pull a guide you take some of the head out with it.
So as a rule of thumb you should never put the old guide back in.
The process I use for guides is to heat in an oven to 350 deg C for about /2 hour, pull the head out & drop it onto blocks covered with an old blanket .
Spray the guide from the inside with some of that liquid freeze you get from electronics stores followed by a sharp tap if necessary as they oft fall out under their own weight once you hit them with the freeze spray.
I have a big set of guide removers & replacers but I have found they do more damage than they are worth on alloy heads.

Replacing guides is same process.
Heat head. freeze guide on the drift you are going to use to insert it theo put of the oven out of the freezer and tap tap tap.

More good info for home enthusiasts. But the creep point of Aluminum was verified on several engineering sites and the same 380-390 F came up for the point at which aluminum begins to soften. Dr Google or no, these sites were not forums like this one. Other supporting evidence of softening is auto head rebuilders who perform scratch test of incoming heads for repair and reject "soft" ones. I was going to have the Intek Brinell tested , but decided not to as very little readership was interested. The reinstalled guide was a dubious experiment and when it moved again I believe it was due to the weakened aluminum head. When I stand back and look at the little Intek head I wonder if it needs more finning? Finally I have seen guides with metal O rings , but I think they were topside. What's your take?

I finally got my hands on the correct flywheel! But the saga isn't over, my new dilemma is installing the springs that make the pawls on the flywheel move when you pull the starter rope. How do you install them?

Grassbandit said:

I finally got my hands on the correct flywheel! But the saga isn't over, my new dilemma is installing the springs that make the pawls on the flywheel move when you pull the starter rope. How do you install them?

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Ok I got it, there's a little trick involved and some measure of patience. Once I got it all reassembled I ran into another issue with the clutch eating the plastic recoil housing so I corrected that by putting a bigger washer under the clutch and now its all good.
thanks everyone for sharing knowledge.

Bandit, Let us know if it starts.

Starts and runs perfect, idles nicely. Will post more pics soon