My Bike doesn't want to rev, it's doing my head in. Only just bought the bike and this problem was there. It pulls off nicely, first gear is non existent as it revs up to quick and splutters. If I go through the box it's pretty quick, but it only feels like it's revving to bout 4k. It Starts to fart.

This is what I've done to try and rectify it:

The Air filter is brand new
Brand New plug
Stripped Front pipe and cleaned inside
Stripped Tail pipe and re packed it
New Main jet and pilot jet
Carb stripped and cleaned, even emulision pipe
Air/mixture screw checked and ok
Oil pump setting is ok
Fuel Tank drained and cleaned, fresh fuel

A lot of smoke comes out the tail pipe, like it's running rich. The old plug was very oily. I just don't know what else to check, please help

cheers, adam

Did you check.

timing ,, tdc and all that
reed valves
choke actuator,opening/closing
air box is sealed along joints
power valve ,, actuator..does it freely move
is you oil mix pump set right ,,..you could disconnect this and premix oil with your petrol to see if engine revs better?
To me the spluttering sounds like theres some air getting into the carb from somwhere or by the reeds ,,

does it act and sound like your trying to rev the tits off it with the choke on??cough/cough splutter/splutter

if all else fails give the engineers a ring at leisure trail

Cheers for the reply. You've given me some good things to think about.
I was wanting to check the reeds, as the bloke said they were after market ones, maybe they;ve worn out etc..

I haven't checked the timing, I guess that's a good place to start

The Air filter is sealed well with a type of filter sealent

There is a pipe tapped off the secondary side of the carb, just before the reed block. Wonder if that could be slightly splt.

The oil pump is set right, if all else fails then i'll disconnect the oil pump like you say. Any idea on what grade the premix should be (50/1?)

It sounds just like you say, like the chokes jammed on. The choke operates fine though. Just wanna be able to ride the bike, when this is sorted it'll be a nice bike. Thanx for the reply mate. I'll spend my saturday giving it another go. gotta get me rear sprocket bolts off, some monkey has rounded them all off, and I got a nice shiney renthal to slip on it.

speak soon, adam

I *think* the pipe you are on about to the carb is a coolant one, if so there would be a coolant leak, Go with CRMrs suggestions - all the right places to start... though I'm not sure you can alter the timing if it's out can you ?

edarter wrote:I *think* the pipe you are on about to the carb is a coolant one, if so there would be a coolant leak, Go with CRMrs suggestions - all the right places to start... though I'm not sure you can alter the timing if it's out can you ?

sortof........... viewtopic.php?t=874&highlight=

get the files out guys - time to tinker with the timing !!!

lol

Now then, gonna have an interesting read tonight with that one. Cheers for that, i'll set about reading it later. It aint the coolant pipe on the carb I meant, it's actually on the rubber connectter pipe which connects the carb to the reeds. Cheers for help though. This saturday i'll hopefully check

Powervalve, make sure cables free etc.
Timing, gonna skank one of these guns from somewhere, or get someone else to do it (easier)
Check the reed block

I was hoping to go out on it this weekend, looks unlikely. Can't wait to poo myself on it though,

Don't ride behind me, gonna be some poo flying

Hiya,

Sounds like a fractured reed to me but best to check all the obvious stuff first, plugs, air filter, etc.

Timing is fixed on the CRM so no need to worry about that.

I would also check float height, see whether the floats are punctured or not.

Give me a shout if you need more help. B.

cheers for that. I take it it's easy to tell if a reeds knackered or not. There supposed to be boysen, but u'll get told anything when buying a bike. Fingers crossed it's something fairly cheap, don't fancy buying a new CDI etc. i'll post a message tomorrow night with my findings.

Thanx again people for comments

regards adam

Just checked the reed pettles, look fine to me, snap back fine and no sign of fracturem, was kinda hoping it would be as easy as that.

Gonna check float height now, not sure what kinda height i'm looking for, anyone there for a quick response?

Failing that, it's time to check the powervalve.

speak soon

Slip the side cover off the powervalve and check it's movement mate, see what happens there?

There are loads of threads about how to check your powervalve is working so have a look at these? Might help.

Cheers....Let us all know what you find?

Pearse,

LT will be able to tell you the float height.

I re-read your original post, have you tried a compression test? Anything over 100 psi is fine. If you are local to me in West Sussex I am happy to lend you a compression tester.

Let me know how you get on.

Bargos.

Hi Adam,

I have a mk3, which has the exact same problem/symptoms !!.. This is what i have done so far to rectify it:-

1. Isolate the cut-out switch
2. Isolate the sidestand switch
3. Piston rings bore wear all OK (in amazingly good original condition, confirming its 10K Japan commuter history) checked for cracks/faces/gaskets etc.
4. New air filter and checked all banjo's/airways etc.
5. Thoroughtly cleaned carb and new jets/checked float height/checked the needle
6. Checked the PV open/close (remove the pipe). Fully counter clockwise is fully open. Clockwise at the markers is fully closed.
7. The PV does open fully when revving the motor (but the engine won't clear, like the choke is still on)
8. Swapped pipes and silencers with new DEP/Originals
9. New coil/HT/Cap/plug
10. Tried new reeds
11. Its not using ang gear oil...so the crank shaft oil seals seem OK.
12. I have tried disconnecting the autolube and running 40 - 1.

With no success....the bike sounds great in the garage, unless its help 'wide-open'.

Next steps......

1. Strobe the ignition timing marks & check the woodruf key. Check the voltage from the lights (my bulbs are not blowing...) making sure its DC not AC. Should be apx 12v at the lights. Out from the generator it should be 15 - 20 volts AC (not sure how you can measure this)
2. Re-wind the AC generator (£90.00)
3. A new PGM unit (although the PV part of it works OK) & rectifier. David Silver £240.00 and a rectifier from LT at £175.00
4. Ignition pick-ups should produce alow voltage pulse of apx 10w. You need a peak voltage tester, to measure this.

Let me know how you are getting on/have you fixed ther problem yet ?. Found myself looking at a new KTM 400 EXC, at the w/e.......

Anyone else....any idea's ?.

Chris
Mobile: 07740 424094

Hi there, sorry bout the late reply, computer has been down for a week, what a nightmare.

Sounds like you've tried everything mate, I checked the powervalve movement, couldn't get back on computer to see what's a cprrect movement so gonna have to research now. Basically........

I took the cover off and started revving me bike. The PV turned slightly, prob bout 10mm max. Thought, yep that's fine. Kept doing it and i noticed it wasn't moving all the time. Like it was when it felt like it. It doesn't seem to open very smoothely either. Checked the cable pully and it seems to pull it with no problem. It's just when the bikes running.

Float height should be 16mm.

Someone did say it sounded like my exhaust was starving it top end, it's got a standard front pipe with an RSV silencer, LT said the RSV wasn't designed for the CRM, it was just modified to fit. But they said it could be down to anything. Think I'm gonna have to pay a bike shop now. I've taken it as far as I can go. Gonna have one last crack on it today. I'll keep yall informed

cheers, adam