Hello DIY go Karts. I'm new to this site. I have a go kart and I installed a legit(not clone) Honda gx200 motor stripped from a pressure washer. Only mod is govonor removal. I was ripping it hard at my friends farm yesterday and I didn't take many breaks to let the engine cool down. The engine was loosing power and backfired so I killed it. And since then I haven't been able to start it. Check the compression and it has 35psi. What do I need to do? I read that the auto-decompression could have been locked so I attached a drill to the flywheel nut and spun engine backwards. Still 35 psi. Thanks for any help in advanced.
Honda GX200 overheats then looses compression
- Thread starter Justin_s
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Abtheman28
Member
Yup sounds like it's time for a rebuild....ya may as well get a billet rod and flywheel at the same time so you avoid having to strip the motor again at a later date. Stock flywheels are known the fly apart once the governor is removed and the stock rods fly out the side of the motor at high rpm....
well.. IMHO with just the governor removed, the engine won't get anywhere near a dangerous rpms for neither the flywheel nor the conrod.
As soon as you increase compression (sorry, hehe.. but yes
) you might want to think about the conrod,
and as soon as you play with the idea to install heavier valve springs to get rid of the valve flutter at around 5000-5500 rpms you want both.
Now, it might be indeed the cam (and the compression release)
if you for example forgot to remove that flimsy little washer that sits behind the governor..
that might have rattled loose and got stuck somewhere (even in the cam)
Easy to test without disassembly though, just seal the exhaust for good,
the decompression acts against the exhaust valve and if the exhaust is blocked,
the cylinder has something to work against
So try that first.
if you still do not get satisfactory compression,
check the head first, remove the valve cover and check if the intake valve got stuck,
(you can also see and observe the compression release on the exhaust valve)
if that's the case, stop here and open the crankcase
(a lifter issue, maybe a bend pushrod...)
check cam alignment again after checking and reinstalling everything else.
And if that's all good solid, clean and without debris (tiny washers)
you likely blew your head gasket for some reason.
(head not torqued to specs perhaps ?? but why?? *shrugs*)
then, check and reset valve lash where necessary and you'll be good.
'sid
PS okay if you find shards of metal in your oil... you need to find the origin and act accordingly of course ... no need to mention that, I guess
As soon as you increase compression (sorry, hehe.. but yes
) you might want to think about the conrod,and as soon as you play with the idea to install heavier valve springs to get rid of the valve flutter at around 5000-5500 rpms you want both.
Now, it might be indeed the cam (and the compression release)
if you for example forgot to remove that flimsy little washer that sits behind the governor..
that might have rattled loose and got stuck somewhere (even in the cam)
Easy to test without disassembly though, just seal the exhaust for good,
the decompression acts against the exhaust valve and if the exhaust is blocked,
the cylinder has something to work against
So try that first.
if you still do not get satisfactory compression,
check the head first, remove the valve cover and check if the intake valve got stuck,
(you can also see and observe the compression release on the exhaust valve)
if that's the case, stop here and open the crankcase
(a lifter issue, maybe a bend pushrod...)
check cam alignment again after checking and reinstalling everything else.
And if that's all good solid, clean and without debris (tiny washers
)you likely blew your head gasket for some reason.
(head not torqued to specs perhaps ?? but why?? *shrugs*)
then, check and reset valve lash where necessary and you'll be good.
'sid
PS okay if you find shards of metal in your oil... you need to find the origin and act accordingly of course ... no need to mention that, I guess
Whitetrashrocker
Inmate #952016
Just to add to sids advise,
Take a spoon full of oil and pour it in the spark plug hole and do another compression test before tear down.
If the rings are bad and causing the bad compression issue, the oil will give a temporary seal and your test will show higher numbers.
How long was this engine on the pressure washer?
Take a spoon full of oil and pour it in the spark plug hole and do another compression test before tear down.
If the rings are bad and causing the bad compression issue, the oil will give a temporary seal and your test will show higher numbers.
How long was this engine on the pressure washer?
Hello everyone. It turned out that my compression tester was broke lol. I used my neighbors snap-on tester and it read 47psi. The real issue had nothing to do with it overheating. The flywheel key was sheared. It was from when I tightened the flywheel. The pull starter broke so we drill started it but i remember that if i didnt remove the socket quick enough the flywheel nut would come loose. So pretty much after removing the engine and draining the oil and removing the crank cover, it was a simple fix lol. Thanks to all of you guys who helped
KartFab
Active member
Hello everyone. It turned out that my compression tester was broke lol. I used my neighbors snap-on tester and it read 47psi. The real issue had nothing to do with it overheating. The flywheel key was sheared. It was from when I tightened the flywheel. The pull starter broke so we drill started it but i remember that if i didnt remove the socket quick enough the flywheel nut would come loose. So pretty much after removing the engine and draining the oil and removing the crank cover, it was a simple fix lol. Thanks to all of you guys who helped
you might want to actually tighten it to 55+ ft pounds, and if you cant do that, at least impact it on there with an impact wrench. You might go shearing another key if its not torqued down to spec.
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