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Hi everyone,

First of all I am knew to these forums, also I am amateur at small engines and I just do simple repairs for a hobby, but this problem got me stuck.

I have a Briggs and Stratton engine attached to a Victa lawnmower with the following specs:

Model = 92908
Type = 5175 01
Code = 82072308
Horsepower = 3.5
CC = 148CC

So my problem is that when I started the mower on the throttle setting of start, it run very slowly at about 2rev per second and increases after a while after I slow the throttle down and if I try and increase it to near full throttle it just dies and when I try and start it again it won't start, it just starts for 1 rev and dies. I have to leave it for about an hour or so before it will start again and do the same thing

Also to start it I have to take the air filter and air filter housing off otherwise it won't start, I have cleaned the air filter and oiled it.

It has been sitting in one of my mate's shed for who know's long after it wouldn't start and he decided to give it to me to fix, first of all I drained the old oil and put new oil in and the fuel that was in it before had evaporated so I just about half a litre in and it started doing what it is doing now.

What should I do, is their something I can adjust like the idle speed and how? Should I clean the carb?

Thank you in advance

You are going to need to remove and clean the carb, and most certainly replace the diaphragm between the carb and tank. May also need to clean the junk out of the fuel tank, because it will come back to get you, by clogging up the filters on the fuel pipes.

ILENGINE said:

You are going to need to remove and clean the carb, and most certainly replace the diaphragm between the carb and tank. May also need to clean the junk out of the fuel tank, because it will come back to get you, by clogging up the filters on the fuel pipes.

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If I want to clean the carb, can I use any carb cleaner e.g. car carb cleaner. Also is it still possible to buy the gasket between the carb and tank or will I have to cut one from gasket paper. Then for cleaning the petrol tank, do I remove the petrol tank and wash it out with water and then let it dry?

Thank you in advance

Get rid of them damn points, would be the first suggestion/. Pop on a good used electronic coil!!!!!

Lachiepower0402 said:

If I want to clean the carb, can I use any carb cleaner e.g. car carb cleaner. Also is it still possible to buy the gasket between the carb and tank or will I have to cut one from gasket paper. Then for cleaning the petrol tank, do I remove the petrol tank and wash it out with water and then let it dry?

Thank you in advance

Click to expand...

After you dump water out, check for rust, if no rust let it dry and if the tank has any rust, just put some small stones (pea gravel) about the size of a pencil eraser in the tank. Put in about two hand fulls of gravel and shake it up for some time and that should knock off most of the rust, pour out the gravel, look inside, repeat if necessary.

Lachiepower0402 said:

If I want to clean the carb, can I use any carb cleaner e.g. car carb cleaner. Also is it still possible to buy the gasket between the carb and tank or will I have to cut one from gasket paper. Then for cleaning the petrol tank, do I remove the petrol tank and wash it out with water and then let it dry?

Thank you in advance

Click to expand...

car carb cleaner is fine, yes the gasket is available, and I normally put some sort of solvent, or even spray carb cleaner in the tank and add a handful of nuts, like the type that go on bolts, or sometimes marbles, and shake.

Lachiepower0402 said:

If I want to clean the carb, can I use any carb cleaner e.g. car carb cleaner. Also is it still possible to buy the gasket between the carb and tank or will I have to cut one from gasket paper. Then for cleaning the petrol tank, do I remove the petrol tank and wash it out with water and then let it dry?

Thank you in advance

Click to expand...

Paper gasket wouldn't work. You will need the proper gasket because its also the fuel pump.

So I have made a bit of progress with it, I decided to buy a new spark plug because I thought that maybe my mate put the wrong spark plug in and he did, I bought a NGK B2-LM and it worked a lot better and it ran at a higher rpm that before but it still does not seem to be perfect. Also the spark plug is larger

I have also ordered a new air filter from my local mower shop for only $8 which is pretty good.

I am going to buy carb cleaner today at the local car shop and clean the carb and wait for the new filter before starting it again.

I also looked inside the fuel tank and it is as shinny as the new spark plug!

Also regarding the spark plug, I noticed that when I took the new spark plug out of the engine after running it, the spark plug was black, how can I tune this carb or is this just a thing that can be fixed by cleaning the carb?

Thank you in advance

I've found something else to work on the mower in the progress. I have decided to remove all of the rust off the mower and repaint it, at the moment I am hand sanding the paint off rusted metal down with 80 grit sandpaper, is this right? and is their a easier way? Then when I get to painting it what should I use?

Thank you in advance

Just use Rustoleum Rusty Metal Primer, and paint right over the rusty metal, then final coat on the color you desire. But that won't help your ignition problem...

Yeah I know, but I also want to make it look good while I am working on the engine.

So with my question before, how can I tune the engine so the spark plug is not black after running the engine, I have already cleaned the carb once, but I might do it again because I think I missed a few spots.

Also I removed 3 cylinder head bolts from the engine accidentally thinking I need to take them off to remove the carb, What torque setting do I have to set them to when reinstalling them?

I still have to find a gasket for between the fuel tank and carb

I looked around online for a gasket for this mower for between the fuel tank and carb and I found this:

Diaphragm-Carburetor [391681] for Lawn Equipment | eReplacement Parts

It looks like the right one it is for model #92900 mine is model #92908

Could someone please tell me how to tune the carb for my mower and what torque setting to torque the cylinder head bolts to.

Thank you in advance

http://outdoorpowerinfo.com/engine_specs/briggs_valve_gaps.asp

Save and explore this site, it has all the info you need to know.....

Fish said:

http://outdoorpowerinfo.com/engine_specs/briggs_valve_gaps.asp

Save and explore this site, it has all the info you need to know.....

Click to expand...

Thanks,

That website is very helpful

Regards,
Lachiepower0402

So far I have, cleaned the piston, cylinder head and valves of any carbon, cleaned the carb and washed out the fuel tank. I have yet to torque the cylinder head because my torque wrench is in a box and I'm moving.

What else can I do in the meantime?

So like I said in the last post, I have cleaned everything that I think needs cleaning. Reinstalled the head bolts and tried to run it. It runs but is still rough. Also I have noticed that the auto-choke is not working.

I have to open the choke with a screwdriver and leave it open while it is running otherwise to goes down to a low rpm. When I open the choke it jumps to a high RPM and is rough, then it dies after a while and won't start.

This also means that I can't use the new air filter that I bought for it.

What can I do?

By the way I am running 91 octane fuel is this ok for temporary fuel?

Fish said:

Get rid of them damn points, would be the first suggestion/. Pop on a good used electronic coil!!!!!

Click to expand...

Or at least clean and "regap" your old points!!!!!!! Dang..... In the old days, that was a main part of a "tuneup"!!!!

Are you serious about these posts?

Would this tool be alright for the job
BikeMaster 12 Blade Combination Tappet and Feeler Gauge Set - In stock NOW! Shop BikeMaster Today

What size gap should the points be?

Thank you in advance

I've got a feeler gauge now,

Could someone please tell me what gap I need to set the points to so I can complete the procedure or tell me where I can find the information I need.

Thank you in advance

I tried to undo the flywheel nut that was on top of the flywheel but it wouldn't budge, I tried hammering it with like in the video and it wouldn't move an inch.
I will have to either buy the tool that is required or go to the mower shop and get them to do it.

I got the automatic choke working, the little arm that comes from the fuel tank was out of the place that is sits in under the cover on the carb.

Also I do not have any spark anymore, so their must be something wrong with the points.

Yeah, that is why I am a big fan of advising folks to swap the engine over to an electronic coil, lawnmower shops usually have piles of good used ones laying around, and no need to try and pull the flywheel.

So could I remove the coil looking thing that is next to the flywheel that connects to the spark plug, what is that anyway? and put a magneto in its place?

Yeah, you just need to cut the wire going under the flywheel, and bolt on the new coil with a business card, you just need to hook up the coil to the kill wire circuit so you can shut the engine off..

Amazon

Would this also work, because at the moment I don't have any used coils and I wouldn't know which one to get and my local mower shop wouldn't have it.

coil numbers....

briggs 793281, 697036,398593,496914.
Oregon 33-342

Hell, stop buying chit and listen to me!!!! Your local shops have those coils laying around!!!!! When a shop junks out old mowers with bent cranks, they
usually save good starters, coils, tanks etc....

The new college grads at Briggs just want you to buy a new engine or new mower. They have no clue how to help you fix a 30 year old engine, as most of the kids here...

Oh, whatever............

No the guy at my local briggs and stratton dealer is an old bloke who know's what he talking about, but when I asked him if he would service a 1970's mower he told me it was not old enough for him to service meaning he only services before 1970's that can't be right, no wonder he gets no service. Besides that he is good for parts like fuel lines.

Well, he must be "right"....

Fish said:

Well, he must be "right"....

Click to expand...

Should I just get one of the coil's that you listed in a previous post?

Well it would cure the "spark" problem.

I will be getting this coil

Amazon.com : 496914/793281 Briggs and Stratton OEM Coil : Lawn Mower Parts : Patio, Lawn & Garden

Do you also know where I can get the clamp and screw that clamps the throttle cable against the body of the mower so the cable does not move when you operate the throttle, as I am missing that and I have to operate the throttle manually.

Don't worry, I found the throttle cable clamp, it is part number 22372 or Substitute part number 692179.

Another question, when I was cleaning the carb, I noticed that their was a white wire connected to a piece of metal that hooks somewhere, I suppose this is a ground wire, where does it go on the mower, as it 'hook' into.

Sounds like a kill wire, leave it disconnected for now.

Are you sure that if I get the magneto that you mentioned before in one your posts, it will be able to completely run the engine without the use of the points, because I saw the magneto part number in my parts manual (original) for my mower as a replacement for the magneto that I already have on the engine.

what were those numbers?

Fish said:

what were those numbers?

Click to expand...

One of the numbers that you quoted was 398593, and that is listed in my parts manual for my mower (see attached, file is PDF)

Should I use the retrofit kit that Briggs offers?

Chit!!! Briggs must have had someone on the payroll that didn't go to college!!!!! I am not upset, but see a new good way to sell parts!!!! Thanks.... Have you bought this coil or not?????

Lachiepower0402 said:

Are you sure that if I get the magneto that you mentioned before in one your posts, it will be able to completely run the engine without the use of the points, because I saw the magneto part number in my parts manual (original) for my mower as a replacement for the magneto that I already have on the engine.

Click to expand...

Nah, I am done here.... He will be wanting his money back if there is a problem!!!!! Which he has a 32 year old engine!!!! I am done trying to help here, let the other
dudes here hop in and take control/credit for anything!!!!!

So if anyone is helping me anymore, I have been able to get enough money for the coil and a diaphragm for my mower, they should arrive early next month. These are the parts that I have purchased.

Coil
Amazon.com : Oregon 33-342 Ignition Coil Replacement for Briggs & Stratton 793281, 697036, 398593, 496914 : Lawn And Garden Tool Replacement Parts : Patio, Lawn & Garden

Diaphragm
Amazon.com : Briggs & Stratton 391681 Diaphragm : Lawn And Garden Tool Replacement Parts : Patio, Lawn & Garden

I noticed the coil comes with what looks like a kill wire setup, does this wire connect into the metal thing I mentioned in one of my earlier posts?

I have made a discovery, my engine does not have points, that is why the magneto part number is the same.

I have found out my taking out the old coil and it has only one wire going to it which is the kill wire and on the top of my engine it says Magnetron, which means it is powered my electronic ignition.

What this also means is that I have purchased the right part and that my old coil is busted. This is proven because when I took it out of the engine a piece of plastic fell of it uncovering the coil, which I assume would not be good thing. Also adding to the old coil is very very dirty.

Like I asked before what do about the kill wire that comes with the coil I have ordered, how do I link it up?

I have just received my electric magnetron coil, could someone, if anyone help me install the coil and the kill switch and other parts. This is the coil that I have:

Amazon.com : Oregon 33-342 Ignition Coil Replacement for Briggs & Stratton 793281, 697036, 398593, 496914 : Lawn And Garden Tool Replacement Parts : Patio, Lawn & Garden

Thanks you in advance,
Lachiepower0402