# Got another one



## Lincsbodger (Feb 14, 2009)

Im picking up engines on ebay to fix and build Merry Tillers with, usually 5 HP Briggs engines as I previously talked about on this forum in another thread

Got one here wont start unless you use Bradex Easy Start. Once fired and a bit warmed up, runs ok, unless you open the throttle too far, then it starts to backfire out the exhaust. You have to set the throttle idle screw a fair way in as well, well past the point where it usually has sat, and i think the idle is fairly high.

The only things i can think of that might cause this are 

a) weak mixture - except once running ive tweaked the mixture screw for optimum running. Seems unlikely.

b) air leak on carb gasket - renewed, cant be that

c) what about poorly fitting valves? if the exhaust valve were seating badly and leaking it woudl lose compression at low speeds. Ive seen something similar to this on a Muculloch chainsaw with badly scored bore, once you started it it ran flat out fine, but at low speed lost too much compression down the barrel scores to idle and would die. It would also cause the high speed backfires, since the valve wouldnt effectively remain closed for very long - like having a very acute top node on a camshaft. 

So i might try reseating the valves. What holds the bottom of the valve stems in and whats the quick way to remove them?


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## 30yearTech (Sep 14, 2006)

More then likely it's a compression related issue. Could very well be the valves, I would check the valve lash first to see if you have any clearance on the valves. If the clearances check out, then next I would check the valves and seats to see what condition they are in. I would also check the cylinder for scoring as well.

If the engine is old enough to have point type ignition, that would also be an area to look at.


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## Lincsbodger (Feb 14, 2009)

Hmmm could be right, i took the plug out and peered inside, the exhaust valve looks like its got a woollen mitten. I would guess its lack of valve seating. Have to wait till next weekend. I also bet the piston ring/s are worn, if thats the case.

What holds the valves in? on a large engine its usually a pair of tapered collets and a sleeve, i presume its not that elaborate on small engine?


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## 30yearTech (Sep 14, 2006)

The valve keepers are usually just slotted with a small hole in the center and a larger hole towards the outer edge, they slip off and release the valve. If the exhaust valve has a rotator on it, then it will have the keepers like you described.


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## Lincsbodger (Feb 14, 2009)

UPDATE:

Well i cut the valves back into there seats and cleaned them up till they were all shiny and new looking  , the compression is awesome, nice big fat spark - but it still needs ether to start it. At least it doesnt fart and pop at full throttle now.

Looks like something funny going on in the carb. Ive cut some more gaskets from gasket paper, and its got a new diaphragm. The only thing i can think of now is that theres a partially blocked channel in the carb.


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## CHUY68 (Aug 20, 2008)

i have a project, its a merry tiller im working on this weekend it needs a new muffler, carb repair kit , fuel tank clean. i just bought the emblem sticker for this engine last night. i will paint the whole engine soon after getting it back to good working order. i found the emblems on ebay but cant seem to find parts for the engine, anybody where i can find the carb kit for this engine? its model 80202 0549-05 75011601 briggs & stratton 3 hp
thanks in advance
jesse


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## Lincsbodger (Feb 14, 2009)

Hi

Thanks for hijacking my thread.

Do you have a solution to my problem? Otherwise I suggest you delete your post and start your own thread, which is nothing to do with this one..............


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## 30yearTech (Sep 14, 2006)

CHUY68 said:


> i have a project, its a merry tiller im working on this weekend it needs a new muffler, carb repair kit , fuel tank clean. i just bought the emblem sticker for this engine last night. i will paint the whole engine soon after getting it back to good working order. i found the emblems on ebay but cant seem to find parts for the engine, anybody where i can find the carb kit for this engine? its model 80202 0549-05 75011601 briggs & stratton 3 hp
> thanks in advance
> jesse


The type of carburetor on this engine usually does not have kits available. You can get most all the parts for it from any Briggs and Stratton dealer, or you can find them on the web at Parts Tree, Jacks small engines, or Sears to name a few.


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## 30yearTech (Sep 14, 2006)

Lincsbodger said:


> Hi
> 
> Thanks for hijacking my thread.
> 
> Do you have a solution to my problem? Otherwise I suggest you delete your post and start your own thread, which is nothing to do with this one..............


No reason to get upset, I think we can all cover both issues without too much confusion. 

What is the model and type number of your engine?


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## CHUY68 (Aug 20, 2008)

*sorry about the , my bad*

 sorry lingbooger did not mean to make you upset. hey we got something in common , we both own a merry tiller :wave:


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