Question for Experts

[FMF215]

Ok guys i got a problem that im stumped on...i just bought an 86 250R and the first day i brought it home all went well just a little spill out of the back bottle of antifreeze....the second day i took it out all i did was just warm it up and go down the road to my uncles...when i went to leave his house it wouldnt start so he gave me a little pull down the road with his truck and it fired right up and ran good and by the time i got back home it started running ****ty and when i shut it off at home sure enought wouldnt start and ended up having antifreeze in the jug...so i toar it down and figured that it was the head gasket and replaced it...when i got it back together it gave me a hard time starting but finally did when i gave it a little pop start with the truck...i rode it pretty hard on a flat track out back for a bit and when i parked it to put the plastics back on it was fine started back up...when it got hot i shut it off and right away started it back up and nothing..tons of smoke and sure enough more antifreeze in jub...not sure y it got so hot so i checked water pump and all was well...im just wondering if any one might know what the problem is? any suggestions would be appreciated! thanks

[pharit]

Originally posted by FMF215
Ok guys i got a problem that im stumped on...i just bought an 86 250R and the first day i brought it home all went well just a little spill out of the back bottle of antifreeze....the second day i took it out all i did was just warm it up and go down the road to my uncles...when i went to leave his house it wouldnt start so he gave me a little pull down the road with his truck and it fired right up and ran good and by the time i got back home it started running ****ty and when i shut it off at home sure enought wouldnt start and ended up having antifreeze in the jug...so i toar it down and figured that it was the head gasket and replaced it...when i got it back together it gave me a hard time starting but finally did when i gave it a little pop start with the truck...i rode it pretty hard on a flat track out back for a bit and when i parked it to put the plastics back on it was fine started back up...when it got hot i shut it off and right away started it back up and nothing..tons of smoke and sure enough more antifreeze in jub...not sure y it got so hot so i checked water pump and all was well...im just wondering if any one might know what the problem is? any suggestions would be appreciated! thanks

Was it just let over anitfreeze left in the jub from the first time?

but do you shave you head gaskets? i had friend of mine do this to mine and he put it in wrong and it was leaking into the jub. lucky i found it before anything bad happened.

but if not check to see if you cylinder or head has got a crack in it anywhere. that would be the only thing i could think of.

[Eddiesanders250]

you should drain your oil, check your piston to see if it is ok, and replace your coolant. if coolant gets into your cylinder your piston can crack after it gets hot. You really should have drained your oil because it is not good to have coolant in your engine. by the way i am not an expert.

[beerock]

drain the oil where? its a 2 stroke.....

sounds liek maybe a warped head not sure though..

whats your compression? if its high enough, you may need to get a new gasket and spray permatex copper coat on it, let it set and then put the gasket on and bolt it up.... make sure both mating surfaces are clean as well....

if it keeps doing it you could have a cracked cylinder... i doubt it though...

check your compression first...


also what bore is it on?

[atvmxr]

there is like a million to one chance this happened, but what you are describing sounds alot like what I encountered a few years back. The sleeve in my jug actually dropped down in the cylinder about a 1/32" or so. I could never get a head gasket to seal up and couldnt figure out what was going on. just something else to check when you have it apart

[FMF215]

ya someone else mentioned the head being warped as well...im not sure im going to take it apart again and check it out...im pretty sure the cylinder is not cracked it looks fine...i will check to see if it dropped at all...im just pretty stumped cuz it only happens when it gets hot?

[FMF215]

its bored to i believe 68mm so im not even sure what i should have for compression? any ideas?

[BLACKeR]

that fact that you haver to pull/pop start it so much leads me to believe you never have had good compression. if you cant kick start a quad but you can pop start it its usually a good sign that your compression is low. a warped head sounds the most likely to me. your compression should be around 150-160 i believe. i might be wrong though. its been a while since i had stock compression.

[beerock]

Originally posted by BLACKeR
that fact that you haver to pull/pop start it so much leads me to believe you never have had good compression. if you cant kick start a quad but you can pop start it its usually a good sign that your compression is low. a warped head sounds the most likely to me. your compression should be around 150-160 i believe. i might be wrong though. its been a while since i had stock compression.

right either that or the top end is worn out.

only way to tell is by testing compresion

atvmxr does have a point that i forgot about, if the sleeve walked and was pulled down you will never seal a gasket this could be your problem

[LSR265R]

Originally posted by FMF215
it wouldnt start so he gave me a little pull down the road with his truck

The reason for not starting could also be your CDI.

[FMF215]

yep guys it was a warped head..its getting re surfaced now so on monday it should be good to go i hope

[BLACKeR]

glad to see the "experts" pulled through for you :D

[86 Quad R]

after ya get the hean back and things buttoned back together, check and see what your compression is.