dunny29er
Well-Known Member
its does run fine when i turn the idle (way to high) up but when i put it back to normal idle it cuts out
how do u check for cracks
and no i was there with him at the time he didnt touch that
engine cutting out (not the valve clearance)
- Thread starter dunny29er
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its does run fine when i turn the idle (way to high) up but when i put it back to normal idle it cuts out
how do u check for cracks
and no i was there with him at the time he didnt touch that
dadof2
Well-Known Member
post a video of it running the more info you give the better
if it runs fine but needs a higher idle id say its carby how high do you consider it to be as in revs
where is ya mixture screw set at, what pilot and main you running,
have the idle so it will just run and spray wd40 around the carbie and the manifold listen to see if the revs increase
if it runs fine but needs a higher idle id say its carby how high do you consider it to be as in revs
where is ya mixture screw set at, what pilot and main you running,
have the idle so it will just run and spray wd40 around the carbie and the manifold listen to see if the revs increase
sean01
Legend Spanner Spinner
this issue is also caused by shit in the pilot jet or floating around in the carb..
dadof2
Well-Known Member
yeah id put money on this not being a valve
dunny29er
Well-Known Member
i have a 26mm oko fateside race carby kit with 96 main and 36 and i cleaned the main jet but i cant get access to the little jet as i cant get the bowl off because the screws are on way to tight and i dont want to risk stripping as i did the same to another carby and i wish i could get a video but that would mean trying to start it for half an hour and even then im not sure it will start
dadof2
Well-Known Member
well if you cant check youre pilot stop now put tools away and take it somewhere cos if 2 screws have you at a dead end there is little hope you can fix this by yourself
pbk
Well-Known Member
well your going to have to get it off
ask your dad to do it for you, i find those stubby Philip heads screwdriver works best, i have also heard about using a soldering iron on the screws to heat them up obviously do this when there is no petrol in the carby and let the fumes ventilate out of it
sean01
Legend Spanner Spinner
also im 99% sure these engines have factory fitted decomp mech on the cam, which will result in the exhaust valve being held open during some stage in the cams rotation..
but yeah you need to get the fuel bowl off so you can clean the carb out with compressed air..
but yeah you need to get the fuel bowl off so you can clean the carb out with compressed air..
dunny29er
Well-Known Member
ok will do now thanks guys let u know if i get it off
dunny29er
Well-Known Member
ok so i took it off (after drilling out the screws) and cleaned it all and the jets but still nothing but i think because there is hardly any compression and since i saw the exhaust valve had bent so its escaping through it so there is hardly an compression but that just what i think what do u guys think?
sean01
Legend Spanner Spinner
you need to take it to someone that knows what there looking at.
iv already explained that engines can run fine with bent valves so i recon your problem is other than a bent valve..
actually we have been running a 110 with a bent valve for about 6 months or more, at first it was pretty bent but we straightened it in the head with a hammer.. still leaks on a leak test too.
also a bent exhaust valve will pop or sound funny thru the exhaust..
check, double check then re check your valve clearances. they are easy to fudge up.
might even be worth trying another cdi and coil on it..
sorry but thats all i can suggest at this stage since you have no pics/video's to show us, and your responses aren't the easiest to read most of the time.. try some comma's and full stops occasionally.
iv already explained that engines can run fine with bent valves so i recon your problem is other than a bent valve..
actually we have been running a 110 with a bent valve for about 6 months or more, at first it was pretty bent but we straightened it in the head with a hammer.. still leaks on a leak test too.
also a bent exhaust valve will pop or sound funny thru the exhaust..
check, double check then re check your valve clearances. they are easy to fudge up.
might even be worth trying another cdi and coil on it..
sorry but thats all i can suggest at this stage since you have no pics/video's to show us, and your responses aren't the easiest to read most of the time.. try some comma's and full stops occasionally.
dunny29er
Well-Known Member
lol sorry, yer will try that
dadof2
Well-Known Member
get ya phone out or bloody well borrow one
i rebuilt a 150 head 4 days ago
the exhaust valve was held open slightly by a piece of carbon but the bike still ran fine just smoked on startup initially i thought v stem seals
after a clean up and relap it sits in sweet and passes a leak test
this is what i think you can see on youre valve but without pics its a 50/50 guess
got any mates with a similar size engine
swap carby then test
swap c.d.i then test
swap coil then test
do a check on all wiring, strip it right back make sure its all clean and constant conections .... then test
swap stator plate then test
if you have done all the above to the best of youre abbilities and its still screwed
fork out some $$$$$ and take it to a shop
or ask nice here ,there may be somone in youre area willing to have a look
we wont be able to help you without more detail that we can see for ourselves
these bikes are basic yet can still be a woman at times ,a fault that you cant find may be solved with a fresh set of eyes
ive had an electrical gremlin that had me stumped took it to thumps....... (r.i.p mate and thanks)
had him scraching his head for an hour then he noticed the dry solder joint on the coil, that when it got hot would make it just die re soldered joint and all good
end of essay
i rebuilt a 150 head 4 days ago
the exhaust valve was held open slightly by a piece of carbon but the bike still ran fine just smoked on startup initially i thought v stem seals
after a clean up and relap it sits in sweet and passes a leak test
this is what i think you can see on youre valve but without pics its a 50/50 guess
got any mates with a similar size engine
swap carby then test
swap c.d.i then test
swap coil then test
do a check on all wiring, strip it right back make sure its all clean and constant conections .... then test
swap stator plate then test
if you have done all the above to the best of youre abbilities and its still screwed
fork out some $$$$$ and take it to a shop
or ask nice here ,there may be somone in youre area willing to have a look
we wont be able to help you without more detail that we can see for ourselves
these bikes are basic yet can still be a woman at times ,a fault that you cant find may be solved with a fresh set of eyes
ive had an electrical gremlin that had me stumped took it to thumps....... (r.i.p mate and thanks)
had him scraching his head for an hour then he noticed the dry solder joint on the coil, that when it got hot would make it just die re soldered joint and all good
end of essay
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dunny29er
Well-Known Member
ok thanks guys well only half of the valve is open so its bent if it was carbon build up all around it would be open
dadof2
Well-Known Member
wrong wrong wrong
as i said
not 4 days ago i had a exhaust valve that i could see light through 3/4 of the way around it WAS 1 small piece of CARBON
now sean has said he has a bike with a bent valve that had a quick repair on it and still ran and after repair still runs sean knows his shiiiit i would take his advice
i had an xr 250 nearly 20 years ago that had a majorly bent valve and wouldnt kick over but if enough effort given would bump start and keep running till it was told to turn off
your 140 with a partially sealing valve wont run ........... but a 110,a150 and a 250 do
pack it in the shed or take it to a shop and become one of those ppl that bag chinas and blame there ineptness on it
you have been told it wont be the valve but insist on it being the problem
as i said
not 4 days ago i had a exhaust valve that i could see light through 3/4 of the way around it WAS 1 small piece of CARBON
now sean has said he has a bike with a bent valve that had a quick repair on it and still ran and after repair still runs sean knows his shiiiit i would take his advice
i had an xr 250 nearly 20 years ago that had a majorly bent valve and wouldnt kick over but if enough effort given would bump start and keep running till it was told to turn off
your 140 with a partially sealing valve wont run ........... but a 110,a150 and a 250 do
pack it in the shed or take it to a shop and become one of those ppl that bag chinas and blame there ineptness on it
you have been told it wont be the valve but insist on it being the problem
dunny29er
Well-Known Member
GOT IT FIXED !!! so happy and it was the valve bent it back now has heaps of compression and starts like normal
dunny29er
Well-Known Member
thanks guys for all your help
sean01
Legend Spanner Spinner
i think the most important thing here is being over looked..
he hasnt provided and visual evidence of a bent valve so we can only go by our personal experiences and gut feeling..and try to get him to make sure diagnosis is spot on, specially if he was going to hammer his valve. thats just not something i would want a noob internet taught mechanic to do.
my personal experience has already been told in here with bent valves, and i still stand by what i said.
and as it so happens i repaired another members 125cc engine a while ago (chinaboy) it ran sweet but had a stripped barrel stud and leaked oil bad..
i pulled that engine apart and found what i would call a decent bend in the valve.
sht i recon i still got it in the shed.. again it ran sweet, idled fine, rev'ed fine..
i seen what you deleted cactus hence my post about the decomp mech on the cam.
now about the compression loss...
iv seen heaps of china engines feel like they got no comp, and guess what!! its because the decomp is holding the valve open ALL the time or the valves are set way to tight..
i still cant see how the valve has hit the piston, lol definitely not from a stick..
like i said we flog the absolute piss out of the same engine every weekend and we have NEVER bent a valve..
so you can see again how i wasnt real sure a bent valve was at fault..
next comes carbon build up... an engine that isnt 100% in tune will carbon up quicker than anything and also we cant hear or see the engine is question so we have no idea on its ring quality or oil consumption .. again carbon build will hold a valve open...
and if you notice i wasnt real keen on letting him try and straighten his valve, i still wanted more evidence. which i didnt get or see.. so the next best thing is to check everything else over and over or get him to take it somewhere for a second opinion..
ill tell you what shts me the most tho...
people coming on here asking for help and only providing half the information we need to picture the situation in our heads..
so if anyone is reading my dribble here and is going to post a problem in the future on here, please explain everything good and proper and add as many photos or video evidence as possible... it helps 300%
he hasnt provided and visual evidence of a bent valve so we can only go by our personal experiences and gut feeling..and try to get him to make sure diagnosis is spot on, specially if he was going to hammer his valve. thats just not something i would want a noob internet taught mechanic to do.
my personal experience has already been told in here with bent valves, and i still stand by what i said.
and as it so happens i repaired another members 125cc engine a while ago (chinaboy) it ran sweet but had a stripped barrel stud and leaked oil bad..
i pulled that engine apart and found what i would call a decent bend in the valve.
sht i recon i still got it in the shed.. again it ran sweet, idled fine, rev'ed fine..
i seen what you deleted cactus hence my post about the decomp mech on the cam.
now about the compression loss...
iv seen heaps of china engines feel like they got no comp, and guess what!! its because the decomp is holding the valve open ALL the time or the valves are set way to tight..
i still cant see how the valve has hit the piston, lol definitely not from a stick..
like i said we flog the absolute piss out of the same engine every weekend and we have NEVER bent a valve..
so you can see again how i wasnt real sure a bent valve was at fault..
next comes carbon build up... an engine that isnt 100% in tune will carbon up quicker than anything and also we cant hear or see the engine is question so we have no idea on its ring quality or oil consumption .. again carbon build will hold a valve open...
and if you notice i wasnt real keen on letting him try and straighten his valve, i still wanted more evidence. which i didnt get or see.. so the next best thing is to check everything else over and over or get him to take it somewhere for a second opinion..
ill tell you what shts me the most tho...
people coming on here asking for help and only providing half the information we need to picture the situation in our heads..
so if anyone is reading my dribble here and is going to post a problem in the future on here, please explain everything good and proper and add as many photos or video evidence as possible... it helps 300%
sean01
Legend Spanner Spinner
sorry guys i just had to add to this..
theres no way in hell the gap mentioned above can bleed out as much comp as he is saying.. or make an engine run like he is saying...
to clarify, i said this regarding his idle quality..
one more thing i noticed.. early in the thread he said he has taken the head off before, until now i thought nothing of it because the engine was obviously in a running and decent condition before this problem... now im not quite so sure... (off cam timing maybe)
question... how long ago did you have the head of the first time and for wat reason?
theres no way in hell the gap mentioned above can bleed out as much comp as he is saying.. or make an engine run like he is saying...
to clarify, i said this regarding his idle quality..
one more thing i noticed.. early in the thread he said he has taken the head off before, until now i thought nothing of it because the engine was obviously in a running and decent condition before this problem... now im not quite so sure... (off cam timing maybe)
question... how long ago did you have the head of the first time and for wat reason?
Cactus Jack
Master Spanner Spinner
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We can only go off what the guy tells us ... Who knows ? ... He could have made the entire story up and be having us ALL on ... LOL ...
Some goons flog 4 strokes down a straight in top gear then go into a corner too fast without using the brakes ... frantically tap the gears down to first ... peak rev the engine and let the clutch out to "engine brake" and rail thru the turn ...
So an engine that revs to say 12,000 before the valves float and act as a rev limiter ... now revs thru the roof from the negative force of being pushed ... the valves stop following the cam profile and run out of time with the piston ... then either tap the piston and bend ... or cause a complete Kabanga disaster that wipes everything out ... It all depends on the degree of forced over rev ...
I've had goons do it to my engines and seen countless others do it to theirs ... (mainly ex - 2 stroke riders who get on a 4 stroke) ... As a matter of fact THAT's why springs such as S&W's were so stiff ...
It's more about making the engine idiot proof rather than using the lightest spring necessary to do the job and avoid power loss or a loss in cam lobe life ...
Some goons flog 4 strokes down a straight in top gear then go into a corner too fast without using the brakes ... frantically tap the gears down to first ... peak rev the engine and let the clutch out to "engine brake" and rail thru the turn ...
So an engine that revs to say 12,000 before the valves float and act as a rev limiter ... now revs thru the roof from the negative force of being pushed ... the valves stop following the cam profile and run out of time with the piston ... then either tap the piston and bend ... or cause a complete Kabanga disaster that wipes everything out ... It all depends on the degree of forced over rev ...
I've had goons do it to my engines and seen countless others do it to theirs ... (mainly ex - 2 stroke riders who get on a 4 stroke) ... As a matter of fact THAT's why springs such as S&W's were so stiff ...
It's more about making the engine idiot proof rather than using the lightest spring necessary to do the job and avoid power loss or a loss in cam lobe life ...
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