bike will not reach full revs!!! grrrr

[cr85*]

need help urgently!! i have a cr85, 2003, which will not reach full revs. its fine half or 3quarter but full throtlle it will not have it and when riding will not hit the bands. ive started with the simple, new plug/plugs, cleaned carb, airfilter with no change. then i thought electrical so changed coil, cdi unit, stator still with no difference what so ever. ive tryed changing carb settings, the reeds are ok, different jet in the carb. has anyone else had this problem or known of this problem?? an obviously any help on what it could be??? many thanks

[Off Course Spags]

Do the smaller bike's have a power valve?

I had the same thing with a 250 2 stroke, and my power valve was'nt opening fully

[Still-MX]

I have a similar problem with my YZ250, but it's the rider that won't let it reach full revs

[cr85*]

these 85's dont have a power valve just reed valves??

[Liqueur]

Spags is quite right, a power valve which isn't working causes that problem but being that the 85 dont have one i think you need to check Exhaust and Silencer for a blockage.

[GeorgeMair]

Whats the plug like? Check air in gases out, ie filter through to silencer return carb jets and needle to standard, and work from there. Has there been any modifications to her, is it a new bike to you? If not has this problem only just started?:confused:

[cr85*]

ive done absoultly everying suggested here?? new air filter on it, had the carb apart and everythings normal. plug is near on perfect, theres no mods to the bike apart from a dep exhaust. the bikes new to me but i got it from a mate who i ride with and he had no such problems with it at all. the bike was running perfect then all of a sudden just started doing this?? the spark is perfect, it starts first time everytime just wont reach full revs when in neutraul or a band when riding

[Dobstar#5]

have you checked your top end....
whats the compression like etc

[Gaylord_Fokker]

...it sounds like you have a fuel/air mixture problem..could be many things...sounds like youve covered the basics though


sounds like its fuel starved though.....simple things first

check ...the fuel line isnt clogged...fuel tap isnt clogged...fuel tank cap air vent isnt obstructed...and also check the Carb holder isnt loose .....if all clear you may have to check a little deeper...

check...the choke plunger isnt stuck open....main jet clogged or wrong size...air cleaner may be clogged or poorly sealed or missing...


:xbeer

[cr85*]

again thanks for everything suggested lads but ive done all that too!! the compression is unbelievable on that thing, you can stand on it and it hardly moves, in a good way, obviously not in the way that its nearly seized or anything!! so compression, internals isn't the problem. ive had the carb apart 3-4 times to check and double check things. ive cleaned the tank out as i thought that may be the problem, it has a new filter on it, nothings loose or has any breaks in it. i even took the flywheel off and cleaned the generator plate and stator so all the electric were fine. its a total mystery as this just happened and wasn't a gradual thing??

[Liqueur]

again thanks for everything suggested lads but ive done all that too!! the compression is unbelievable on that thing, you can stand on it and it hardly moves, in a good way, obviously not in the way that its nearly seized or anything!! so compression, internals isn't the problem. ive had the carb apart 3-4 times to check and double check things. ive cleaned the tank out as i thought that may be the problem, it has a new filter on it, nothings loose or has any breaks in it. i even took the flywheel off and cleaned the generator plate and stator so all the electric were fine. its a total mystery as this just happened and wasn't a gradual thing??

Are you taking the p1ss? Why take the stator off and clean it when you had already said in your first post that you had changed all the electrics? As for the compression, you just made me :lol:

[cr85*]

Liqueur - MUG. obviously i changed the stator to rule that out incase cleaning it didnt make a difference and it was that, and as for the compression, theres nothing to make you laugh about that, perhaps you need to get out a bit more i suggest.

[Gaylord_Fokker]

...what ratio you running fella ?

[cr85*]

25mls to every litre. mx7 oil

[Gaylord_Fokker]

25mls to every litre. mx7 oil




...an excellent choice :xbeer




...has the bike been like this since you bought it.....have you changed anything at all ?



..have you spoken to the previous owner about this matter ?

[cr85*]

the bike was fine for about 10 - 12 times of riding until this happened. it just happened as i was riding it, not a gradual thing. when it did happen i hadn't done anything different or changed anything other then a plug and filter which would be the norm after a few rides. its not the plug as since this has happened ive tryed numerous new plugs and checked the filter. i got the bike from a friend and he never had any problems at all!!

[Gaylord_Fokker]

..i dont know matey...if the compression was low ..it would offer a whole new range of possibilities

have you inspected the cylinder head gasket for damage ?

[Off Course Spags]

Is throttle cable routed correctly, if not the slider in the carb wont open fully

[cr85*]

its doing my head in mate, ive asked just about everyone i can, most people say its fuel/air, maybe the wrong carb jetting but it wouldnt have run so well all the other times if it was? i haven't had the head off but would it be that under the curcumstances here?? ive checked the water and theres no black specs or oil or anything un to ward with that??

[cr85*]

yep thottle cable is fine, returning properly if you let go of the grip. could it be electronic advance or anything like that??

[Gaylord_Fokker]

... if compression was low ..it mat be head gasket damage...but with good comp, probably not.


are there any knocking noises when it fails to rev ?

[cr85*]

oh rite. nope no noises, rattles or anything! thats whats so annoying, the bike is totally mint an perfect in everyway apart from it wont reach full revs!! so annoying. it starts first time everytime too

[Gaylord_Fokker]

oh rite. nope no noises, rattles or anything! thats whats so annoying, the bike is totally mint an perfect in everyway apart from it wont reach full revs!! so annoying. it starts first time everytime too



... is the Compression really high ?


this may be down to a carbon build up .... may be worth taking the head off

[cr85*]

yeah compression is excellent. always been like that since i got it. ive never known a small cc bike to be as strong as mine?

[Gaylord_Fokker]

... no offense intended....but at 24 ... arent you a bit big for a 85cc ??

[cr85*]

ha yh you could say that! i have 2002 cr250 aswell but the 85 i use over the fields and up the forest. i dont always have time to go tracks so easyer to take the 85 out. got it dirt cheap too so couldnt refuse the buy!

[Liqueur]

Liqueur - MUG. obviously i changed the stator to rule that out incase cleaning it didnt make a difference and it was that, and as for the compression, theres nothing to make you laugh about that, perhaps you need to get out a bit more i suggest.

MUG? I dont think so, ive done more hours riding and preparing bikes than what you will do in a lifetime.:p

As for compression, its an 85 not a flippin 500, they dont have loads so by the way you describe it something aint right.

One thing that can make a bike not rev out is the breather pipes from the carb block up with crap. Another point would be that if you have been riding it hard 6 hours and it would want a top end overhaul anyway. If you cant fix it take it to your local dealer and pay them to do it for you.

[Eric]

Has spec.

Edited fukc em

[Eric]

Eerrrrrrrrrrrrr hang on, ignore my advise.

I just noticed you ride over fields and in the forrest.

That be illegal riding then ?

I don't like illegal riders bringing down my good name. :mad:

[Gaylord_Fokker]

...and youve never none any illegal riding then Golden Boy ...aye



just cos you dont know whats wrong with his bike....no need to through a nic nac paddy wack ...is there



:lol:

[Eric]

Actually I can say that apart from a 100 yard dash up the street and back ONCE after washing my bike I have never ridden illegally.

NEVER


and I do know whats wrong with it.

[Gaylord_Fokker]

...no ya dont

[Eric]

I very much do so !

[Gaylord_Fokker]

.... he may only have done one ...hundred yard dash into the woods.... so why cant one illegal rider (you) help another off roader (he may own those woods btw)



... ?

[Eric]

If he owns a forest he can chuffin pay me to fix it.

I doubt thet even if he owned a forrest he'd be allowed to ride in it.

[Gaylord_Fokker]

... he may have a wood.... or even a small orchard

[Eric]

Orchard, apples n cider n stuff. cool.

He said "up the forrest"

Hes a notts forrest supporter. :mad:

[Gaylord_Fokker]

Orchard, apples n cider n stuff. cool.

He said "up the forrest"

Hes a notts forrest supporter. :mad:



no such word as forrest




its Notts County ...or Nottingham Forest





ever call Forest ...Notts again...i'll kick ya face in .... mate




alright....lets breath :xbeer

[Eric]

Notts Forest

Nottingham County

:lol:

http://www.mcfc.co.uk/


.

[Eric]

anyway back to a non running CR85 :lol:

[Eric]

sod the illegal wanker

[Liqueur]

sod the illegal wanker


:lol::lol::lol::lol::lol::lol::lol:

My thoughts too after i got called a MUG.