B & S compression problems

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nissinator

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i own a Briggs and stratton go cart engine that will start(sumtimes) but the compression is extremely low and is taking me 5-7hours just to get it to barely start. i have tried spinning the flywheel backwards to check the compression but it just spins back real easy and smooth (same way foward) please help.
 

Bluethunder3320

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okay if your compression is dead you either blew the head gasket or wore the rings down. try to see if air hisses or blows out if the motor head, the top piece, of the engine. if the rings are worn you need to take the entire thing apart and buy new piston rings, possibly a piston if its in bad health.

try pouring soapy water around the head (just a little!) to see if air is leaking out.
 

nissinator

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okay if your compression is dead you either blew the head gasket or wore the rings down. try to see if air hisses or blows out if the motor head, the top piece, of the engine. if the rings are worn you need to take the entire thing apart and buy new piston rings, possibly a piston if its in bad health.

try pouring soapy water around the head (just a little!) to see if air is leaking out.

yep air is leaking out of the head i dont think the piston is wore if so its not enough to replace it and the rings should be fine i checked them about a year ago and :censored: probly would help to put the head gasket on huh. lol i totally forgot bout it and didnt put it on when i put the head back on from checking the values. i also do not have a governor in it but i have the governor arm hole sealed with a bolt. and on the head i made 1 of the bolts to tight and it snapped(from old age, same thing happend in crankshaft) so could that be the problem
 

fowler

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if a head bolt is snapped then the gasket will not work even if it was there.
also how did u forget to put it on
last of all what bolt exactly did u snap on the crank shaft because this sounds pretty bad to me.

oh yeah and are u aware the head bolts have an exact tightess that they must be done up to, it requires a speicail tool called a toque wrench
the bolt thightness settings are the touque settings
 

Bluethunder3320

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b&s website should have a head gasket and head bolt for you. just punch in your model info thats stamped on a metal plate on your engine tin in the search box. did you get the other piece of the bolt out?
 

nissinator

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no i did not get the bolts out of the head and i didnt snap the crankshaft there is just a bolt stuck in there that i cant get out so have to buy a tapping set or wat ev u call it
 

Bluethunder3320

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today i snapped a head bolt on my 8hp briggs, how ironic. i dont know if a tapping set will work because on mine there was still a lot sticking out, and i tried a vice grip, i tried channel locks, and i tried cutting the sides of the bolt off and nothing worked, so it must take a lot of force to move it. also, while trying as hard as i could to move it, my foot slipped and i stomped on the governor arm, and i heard it go snap.
 

r97

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put some penetrating oil in there, liquid wrench? leave it for a while, you should be good to go!
 

DirtTrackRacer_07

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The old Briggs head bolts are brittle in there old ages.

They do not need to be torque realy tight as you may think to do thier job. You need to torque the bolts with a torque wrench instead of your judgement.

I have broke a many of these stuborn things.

If you still have some bolt sticking out of the block, weld a nut or something onto it and see if it will come out.

The heat you put into the bolt from the welder will help free it up some also.

If it broke flush or off in the bolck, center punch it, drill a hole in it, and use what they call a easy out to get it out.

If that don't work, buy a couple high quality drill bits,and start drilling the bolt out.

Buy a couple drill bits below the size of the actual bolt size, that way you can walk up to your hole size and not over drill it. Then get you a tap and re-tap it.

Did you break the bolt off into the crankshaft or is it just stuck in it?
 

jandj

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if a head bolt is snapped then the gasket will not work even if it was there.
also how did u forget to put it on ....

As someone who made his living turning wrenches for 30+ years, I'll tell you right now you'd be amazed at what you can leave out if you're in a hurry, thinking ahead to the next task, or just not paying close enough attention.

If you've never done a job, looked around and saw something laying there and said to yourself "Self, how the hell did I leave that out?" - don't get cocky. It means your day is coming!
 

sideways

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Ive never torqued the head bolts and its fine. Just do them up tight in a cross pattern. Not too tight, just tight.

As you tighten them the shape of the bore changes, that's why you torque them. But back in reality, it doesn't really matter on something like a Briggs, I imagine they wouldn't bore them with a torque plate at the factory anyway.

Thanks

Hayden
 

mrfreyguy

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When you bore out an engine the idea is for it to be as round as possible. If you dont use a torque plate when boring the cylinder will become out of round because of the extra force when you torque down the head on reinstalation. The video below explains better than me.

Skip to 2:12
http://www.youtube.com/user/fiatnutz#p/search/10/SIgq2R_D5wU
 
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