[jeffnott]

450 foreman started blowing back thru carb. took the head off checking the valves. i had to drive the intake valve out it was the tight in the head. the exhaust slid rite out like normal. no marks on piston, nothing else damaged. does anybody know what causes this or is it just time to go out? it is 12 years old.

 

[Helmut]

Did the top of the engine look like it was getting plenty of oil, nothing else looked worn?

 

[jeffnott]

evereything had oil on it just like normal. nothing unusual about it. its just seems like the valve swelled up too tight for the hole causing it to stick

 

[Helmut]

I don't know what would cause that. Did you try sliding the other valve down in the valve seat to see if it fit right and moved freely. If it does, I would just put a new valve in it and hope it doesn't do it again.

I've seen valves stick like that, but only if the engine has been sitting for a long time without starting it.

 

[jeffnott]

yes the other valve slides good in it. guess im just gonna put a new valve kit in and try again.

 

[jeffnott]

i put in new valves and springs problem still not fixed. it blows air out carb even harder. i thinking the timimg mite be off. wanted a second opinion before i start into it because it gonna b a good job to get to the timing chain

 

[shadetree]

if it's acting like my 2000 trx350tm rancher did..when i rebuilt it..and it's blowing gas back out the carb..then your timming is off..i just went through this very same thing..and yes..the timming chain and cam are a b__tch to get to !..unless you pull the motor...does the new valve slide in the valve guide in the head easy ?..if so..then yeah..you got a timming issue..your gonna have to pull the motor in order to get to the cam and timming chain..and you will need a special tool to remove the flywheel. when you get to your timming chain..and you re-align it..make sure you don't do what i did..and use the wrong timming mark on the cam sprocket !!!!..to make sure you got the right mark..after you think you got the right one..look on the lobe side of the cam sprocket..there should be a letter U on the very top of the cam..just make sure you get it facing up.

 

[jeffnott]

i got flywheel and clutch pullers. the manual shows the 450 timing chain in front behind the clutches. sounds like it gonna be a fun afternoon

 

[shadetree]

i got flywheel and clutch pullers. the manual shows the 450 timing chain in front behind the clutches. sounds like it gonna be a fun afternoon

that's odd..the timming chain on my 2000 rancher was in the back of the motor..where the pull starter is..did they move the timming chain on your bike to the front ?.

 

[jeffnott]

its not the 350 rancher its 450 foreman. according to the book i got to pull both clutches to set timing and change the timing chain. its prob the original and stretched so it prob gonna need a new one

 

[shadetree]

its not the 350 rancher its 450 foreman. according to the book i got to pull both clutches to set timing and change the timing chain. its prob the original and stretched so it prob gonna need a new one

yes..i understand yours is a foreman..but..if it's got the same engine design..front to back..instead of the old school..side to side..then i'm thinking the timming chain and cam are in the back..where your flywheel and stator are..if this is the case..your going need to remove the rear covers..unless they changed the design again ??..which doesn't surprise me !!..your going to be taking off the wrong covers to get to your timming chain.

 

[jeffnott]

i looked at book again and it shows the only thing behind rear cover is the flywheel. the pics of front show the chain coming up behind the centrific clutch to cam. its one or the other good odds 50/50 shot lol. either way it gonna b a job

 

[shadetree]

i looked at book again and it shows the only thing behind rear cover is the flywheel. the pics of front show the chain coming up behind the centrific clutch to cam. its one or the other good odds 50/50 shot lol. either way it gonna b a job

hmmm..well..the flywheel is in the rear..and thats where my timming chain was..under the flywheel..then over to the top right..to the cam..anyway..your right..it is a job !..just make sure you line the right timming marks up on the cam sprocket..it really suxs to have to pull the motor out over and over..just to find out you lined up the wrong timming marks..lol.

 

[Helmut]

Yeah, on the 450 Foreman, the cam and chain are behind the front cover, behind the two clutches. It has the longitudinally mounted engine, like the 350 Rancher, except the cam and chain is behind the front cover instead of the rear cover. I don't have any idea why they made them different, but they did.

 

[jeffnott]

i can check clutches and timing all in one lick. this bike aint even mine its the neighbors. i spend as much time workin on it as i do all mine

 

[Helmut]

On the 450 Foreman, you can just stand it up on it's back end and take the cover off. You don't have to pull the engine off.

 

[jeffnott]

is it like the ranchers gotta loosen front end to get driveshaft off

 

[Helmut]

is it like the ranchers gotta loosen front end to get driveshaft off

Yeah, loosen front diff and slide it forward.

 

[Honda3004x4]

Was the timing chain your problem??? Did you fix it

 

[cmanningjr]

Was the timing chain your problem??? Did you fix it

Thread is almost 4 years old...he may not remember.. lol