Seems like surging carby? Not?

[Boudreaux In Eunice La.]

Ok ..... I'll jump in this issue ....... Just change the fuel line..... They will flap on the inside...... Blowing in them does not do any good.....

The only way to know is to put a new one on and line is way cheaper than a carb...........

 

[bertsmobile1]

You can check the secondary windings, ground to spark plug with a multimeter but not the primary because it is in series with a Hall Effect trigger chip.
As they can not be repaired without destroying the chip it is a moot point.
Some of the metal cased plug caps have been known to short out the HT lead.
Check by looking at it running some where dark.

Other than that simply pull off the kill wire as the coil is shut down by grounding.
This bypasses all of the mowers electrics.
IF it sparks both hot & cold then the coil ( magneto really ) could be considered as OK.

Yes WD 40 as dumb and carb cleaner is just as dumb.
A lot of us use it in place of starter fluid as it is a lot softer on the engines.
You really only use it to clean out jet holes in the carbs & clean the exteriour surfaces before pulling them off.

As for the dead stop, I assume you can tell the difference between a flooding stop and lean stop & an electrical stop.
Dead stops are generally electric and tested by removing the kill wire.
The ire just sits on top of the cylinder and melted insulation of a chaffing ground short is not uncommon.

As for fake chain.
Professionals can tell the difference.
In the case of Ross the chain they are fitting had genuine Oregon cutters but fake side plates and drive links.
RGS used to be the Aust distributor for Oregon so their catalogue had all of the parts, you can buy individual Oregon chain parts to repair genuine Oregon chains.
When you look at the way the pins are riveted the difference is quite obvious and in the case of Ross, the chain was hand made, link by link as all of the pins were spun & not riveted.
Oregon continually change the logo & designs on the sides of their bars so when you see a saw with a paint scheme that is 2 years old you know it is fake.
Then when you look at the code stamped into the side of the bars, a lot are not Oregon codes or the 20" bar codes out as 14".

RGS who is one of my wholesale suppliers used to be the distributor for Oregon but Briggs took over as of October 1.
Currently they are selling off all of the bar & chain very cheap but even the sell out wholesale price of the bars is still more than the retail price of no name saws supposedly fitted with an Oregon bar.
Nothing sold by Bunnings has less than a 100% mark up, so a $ 90 retailed chain saw would have a cost price no more than $ 45 by the container load add $ 5 for freight China to Aust which leaves the factory with no higher price than $ 40 at the despatch dock.
The OEM factories will wholesale me a complete saw in parts without either chain or bar for around that price as part of a $ 50,000 order.
So there is no way that saw could have been fitted with a chain & bar made in the USA then exported to China.
Very shortly you will see Oregon in the major retail stores and when that happens Briggs will start to crack down on the counterfeits . They have the resources to go into chain stores buy products then check them for counterfeit parts and take legal actions. RGS did not have that sort of clout. The down side is none of the Australian retailers buy direct from China ( or any other country ) they all buy through local importers even if the importer gets told what to buy from who. Thus the company that ends up being sued is Fred & Sons imports , not the real criminals.
Stihl have just cracked down on one of their suppliers in China preventing them from selling aftermarket parts for Stihl products that are Stihl orange and Husqvarna is following suit.
So expect to see a lot of Stihl & Husqvarna clones in funny colours like Victa blue & JD green . I buy parts direct from these OEM suppliers and got some appologies because the parts supplied were different colours.

As for the quality of the chain & bar, most Ozzies would not have a clue.
People come in with Baumr chain to get sharpened a lot as one of the importers is just down the road.
Nearly all of them leave with new Carlton , Stens or Oregon chain because I will not sharpen a chain that has excessive side plate wear.
Many of these chains have only been used once and the owners jaws drop when I show them how much play there is in the side plates.
The average user will run a sprocket till it has nearly been cut in 1/2 because of excessive chain wear.

 

[bertsmobile1]

And as ot has not been mentioned, get a short bolt to replace the solenoid 7/16" UNF usually but as that is a Chinese motor, could be metric.
Fit the bowl bolt in place of the solenoid, it could have a bad connection or be faulty.
Down here they are not manditory yet.

 

[zenchopper]

And as ot has not been mentioned, get a short bolt to replace the solenoid 7/16" UNF usually but as that is a Chinese motor, could be metric.
Fit the bowl bolt in place of the solenoid, it could have a bad connection or be faulty.
Down here they are not manditory yet.

Thanks so much for your input.

I will replace the solenoid with a bolt before I buy a new $20 coil...

this morning I started it and it still was surging, I manually closed the choke slowly and all it does is stall, The revs did not increase at all as i slowly closed the choke...

I removed the coil and tested it , the resistance values seem OK I have no Manufacturer spec But both Spark lead to metal body and Kill switch to spark lead were exactly the same so I assume that's right
and the kill to the body was 1kohm. I saw a video of someone testing one and it was the same shape and appearance so When he said 1kohm was right I think thats ok...The old briggs one off the old engine measures the same, different mount so couldn't successfully try it out.

Ill try to start it tonight in the dark and see if I can see any spark jumping.

So when i eliminate the fuel solenoid as the issue it's pointing to a coil that tests ok but at operating temperature fails...???

I may just foot the $20 to rule it out...

All very frustrating while watching the grass grow and a very fast pace.

 

[bertsmobile1]

Thanks so much for your input.

I will replace the solenoid with a bolt before I buy a new $20 coil...

this morning I started it and it still was surging, I manually closed the choke slowly and all it does is stall, The revs did not increase at all as i slowly closed the choke...

I removed the coil and tested it , the resistance values seem OK I have no Manufacturer spec But both Spark lead to metal body and Kill switch to spark lead were exactly the same so I assume that's right
and the kill to the body was 1kohm. I saw a video of someone testing one and it was the same shape and appearance so When he said 1kohm was right I think thats ok...The old briggs one off the old engine measures the same, different mount so couldn't successfully try it out.

Ill try to start it tonight in the dark and see if I can see any spark jumping.

So when i eliminate the fuel solenoid as the issue it's pointing to a coil that tests ok but at operating temperature fails...???

I may just foot the $20 to rule it out...

All very frustrating while watching the grass grow and a very fast pace.

A lot of what you see on boob tube is nothing more than shaved monkeys performing.
The gear you need to test the primary runs to around $ 20,000 down here.
Most of the single wire coils can not be tested with a multimeter and in fact a lot of cheap ones will bugger the chip.
You can test the coils used with points using a multimeter.

 

[zenchopper]

SOLVED

SOLVED ! ! !


FIRST
I removed the solenoid and blocked the hole with a piece of rubber and a clamp. ( I couldn't find a bolt with the same thread) Still did the same stall and surge routine.
replaced the solenoid.

I called the place that sells the 17.5HP XP 620, Not where I bought it from, but their competitor.

The place I actually got it from are arrogant and rude, I won't name them, and I will never go back there again.

... actually just another place that assumes that everyone is a two bit amateur and never think that in a million years that you may actually have more experience than them.

But the really nice knowledgeable people who respect you as an equal human I will name because they always go above and beyond their duty to help you with your dumb questions.
Thanks :thumbsup:Jonno and Johno:thumbsup:

I asked if he sells many replacement coils which he said, "yes".

I asked, "is it because they fail?"

He said that they sell a lot because people wire them incorrectly and fry them he couldn't recall a case where he sold a coil which had failed. That was nice to hear.

OK so I wasn't going to order the coil.

We went through a few other possibilities, all things pretty much discussed here.

Then he said that a few times they made the fuel inlet hole a bit bigger with a 5/16th drill bit.

Maybe I misheard him about the 5/16" bit. I didn't really go into great detail of what he was saying. I thought that I'll work it out when I look at it.
So the 5/16" thing might be an entirely different mod.

Before I did anything I started it up and as expected it was surging. As I have the air cleaner box off (filter still attaches) and the cowl off, I had easy access to the choke and throttle
so I very very slowly closed the choke and I got it to stablise for a few seconds. I then did it again, then after three times I was sure it wasn't chance.
.
.

I pulled off the carb again
.
.


.
.
.
saw that the inlet has a JET in it?
So I removed the inlet elbow.
I made the jet a little bigger with a 1.4mm drill bit
You can't quite see the jet hole in the pic but I only made it a little larger
of course, Blew it out with air.
.
.
.

.
.
.
Then in the hole, where the inlet elbow is pressed into, I could see what looked like a black piece of foam.
I got a tiny bit of wire to see if it was a filter or just dirt.

IT WAS DIRT

I blowered it out, and discovered there is a tiny metal mesh grille in there WT ?
,
,
,



Assembled and Works Awesome
.........................................WOO HOOO

I am sort of happy, it was a very frustrating but rewarding journey.

You could say a sweet and sour victory.

This year I am defiantly going to put a blower, nitro, roller cam and rockers on this Chinese Engine and go to the yearly mower races and whip their racist arses....

 

[zenchopper]

A mechanic would have charged you for the coil,

because, when it didn't fix the problem and not being able to return electrical components,

would have just put it on your bill and then charged you to clean the carby, check the valve clearances,
drain your fuel tank, new spark plug and oil and filter etc etc just to cover the 5 hours it took to work it out.

I know because the mechanic who had a shop next to me used to do it all the time....

..sometimes mechanics are not honest because they plainly can not afford to be honest 100% of the time, you'd go broke.

Someone has to pay for the wasted hours.....

 

[zenchopper]

A lot of what you see on boob tube is nothing more than shaved monkeys performing.

TARYL is no Shaved Monkey...he is my hero and brains trust for mower repairs and I will defend him, because I love him

 

[zenchopper]

My mind is thinking there is a stray bit of debris somewhere in the carb that blocks and unblocks randomly which I have missed..

I was right but can't understand why the WD 40 didn't at least smooth it out a little when sprayed int the air cleaner manifold.
Light sprays did nothing, a heavy spray made it rich stall.

I should get some "start ya bastard" for future diagnosis.

Also closing the choke only smoothed it out the very last time I tried it. All other attempts just made it stall.
Maybe I wasn't closing the choke slowly enough to find the sweet spot.

 

[bertsmobile1]

A mechanic would have charged you for the coil,

because, when it didn't fix the problem and not being able to return electrical components,

would have just put it on your bill and then charged you to clean the carby, check the valve clearances,
drain your fuel tank, new spark plug and oil and filter etc etc just to cover the 5 hours it took to work it out.

I know because the mechanic who had a shop next to me used to do it all the time....

..sometimes mechanics are not honest because they plainly can not afford to be honest 100% of the time, you'd go broke.

Someone has to pay for the wasted hours.....

Well I for one do not do that.
And FWIW charge out scheduled hours not actual hours.
And no not a millionaire but I can sleep at night and have an ever growing list of very loyal customer.