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Re: Mk2 starts but wont rev

Posted: 10 May 2014, 14:18
by helisupp
This is very strange, if its not the plug.

Had the piston been out before you bought it, and is it all assembled correctly as things are now sounding abnormal

Re: Mk2 starts but wont rev

Posted: 10 May 2014, 14:45
by Parky265
helisupp wrote:This is very strange, if its not the plug.

Had the piston been out before you bought it, and is it all assembled correctly as things are now sounding abnormal
The bike was running normally until it was dropped in a river by the previous owner (I know the guy and he's not prone to exaggeration). I think at that point the CDi gave up and he put it in the shed. I diagnosed the CDi a year ago and he got a new one but by this time he'd bought an AR so the MK2 was left to rot. I offered him silly money for it and now it is mine and so is the problem. I must say it's puzzling to say the least.
The engine sounds crisp and rumble free and the exhaust smoke clears nicely when it's warmed up. I did notice the temp light is on, on the dash, even though it's not warm.
Gonna go back at it in a moment. Think I might get a trigger sprayer and mist some fuel down the carb and see what happens. :?

Re: Mk2 starts but wont rev

Posted: 10 May 2014, 17:52
by steveb
Could it be the wrong mk cdi has been put on? Worth checking the number on it matches the mk2 number in the FAQs

Re: Mk2 starts but wont rev

Posted: 10 May 2014, 21:12
by fallenmikethebike
Try taking the filter off, it looks very oily.
The bike does look and sound exceptionally rich.
Have you set the float height yet?
Who put the piston in? any chance its in arse about face?
Was tank drained of all the old fuel post it's dunking?
Mike

Re: Mk2 starts but wont rev

Posted: 10 May 2014, 22:20
by twistednuts
Are you sure thats an air filter and not a duck? :?

Re: Mk2 starts but wont rev

Posted: 10 May 2014, 22:26
by knackeredMk1
Change the fuel - quick and easy and removes doubt about excess oil etc. Have you checked the oil pump is set right and returning with the throttle?

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 00:25
by twistednuts
Been thinkin about this all day, really need some kind of a life :D

Keep watchin that vid, its tickin over so well, so the fuel must be kinda good - an surely youve replaced it all after the dunking session.

Sounds like its getting loads of air with the induction stylee, so its either fueling or electrical. I still think it could be either the plug, wrong carb float height or possibly coils? Its the under load part that rings a bell, remember having this problem years ago. Could it also be the ignition windings after getting a good soaking? Just thinking out loud really...

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 08:28
by Parky265
It's torturing me too. Every time I try something new the optimism as I start it is dashed against the rocks of reality.
My plan of action today.
1.Stop crying.
2. Check CDi numbers (if ok start crying again)
3. Swap plugs again (just in case)
4.Tear what is left of my hair out and ring the Samaritans :cry:

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 08:40
by pudzie83
have you tried unblocking the exhaust? seems like something's choking her! is your down pipe standard?

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 09:06
by Parky265
pudzie83 wrote:have you tried unblocking the exhaust? seems like something's choking her! is your down pipe standard?
Yeah I checked the pipe yesterday. It's a DEP and is clear. I even started it without the zorst on it. Bugger innit ? :cry:

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 09:57
by Active Rascal
Are the PV cables definitely connected the right way round?? See if you can whip the cover off and show us a video of the PV movement whilst revved.

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 10:29
by Parky265
Active Rascal wrote:Are the PV cables definitely connected the right way round?? See if you can whip the cover off and show us a video of the PV movement whilst revved.
Cant show that as it wont rev! I checked that it was free and not stuck but cables are on the right way round and I have run and revved MK1's without the RC valve connected at all. :cry:

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 10:42
by Parky265
OK here we go again. I took the air filter off and all the symptoms persisted. So back on with the air filter and let it warm up. I really concentrated on what I could hear and I think I've narrowed it down to an electrical issue.
Look at this latest vid with the choke off. The bike seems to fire with more regularity at low revs but as the revs rise it appears to fire every other stroke.
Plugs have been swapped so it's not that. :?
Any more thoughts fellas?
http://youtu.be/_QEukScqfbI

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 11:57
by twistednuts
Sounds like you might have to change each part of the ignition to cure it, as it could be any :?

Do you know anyone with a mk2 who'll let you borrow thier bits to try?

Re: Mk2 starts but wont rev

Posted: 11 May 2014, 16:47
by Parky265
twistednuts wrote:Sounds like you might have to change each part of the ignition to cure it, as it could be any :?

Do you know anyone with a mk2 who'll let you borrow thier bits to try?
That's what I feared. The lad who I got the bike from is gonna have a dig around for some bits but doubt if he has pick ups etc.
Is there an easy test for the windings and pick ups?