poor running jreg crm

[mr dirt lover]

Hi all this is my first post so please bear with me,

Right i hope that some one could please help before i go bonkers,
i have just bought a j reg crm and it did not run right,but i found a hole the choke channel
on the carb,sorted that BUT she goes good at mid range but if you go slow and wind her on she bogs
and seems to lack power at the top as well,just can't get my head round it.
any body got a idea.

thanks Steve.

[back off road]

whats the jetting ? sounds like a carb issue

[knackeredMk1]

Also check the powervalve is moving.

[mr dirt lover]

Hi and thanks for reply,
looks like running standard jets no numbers i think
power valve is working fine, got a fmf fatty on with fmf back box,when cold she works better,

thanks steve.

[fallenmikethebike]

Check the plug PDQ, you may be running ruinously lean.
2Ts have a habit exhibiting one trait that then turns out to be something else entirely.
Mike

[knackeredMk1]

Quick check - does she run better with the choke on when she's bogging down.

I.e. click the choke on when she is bogging. If she comes immediately back then she's running lean. Only works of a second after you put the choke on though.

[SkidMark]

Am I right in saying that with a FMF system you need to rejet?!?

[knackeredMk1]

How can you say that you have standard jetting when you also say there is no numbers on jets .

FMF doesn't usually need rejetting. When it does it means going leaner.

[mr dirt lover]

Hi
when i took out the main jet Saturday it had no numbers on i think but to be
honest i didn't check properly as i was just cleaning the carb ,but will check
this weekend.
some one said it may be an air leek as it runs on when you shut the throttle
and sounds like it's pinking like a four stroke,
will try spraying some carb cleaner round flywheel and reed block on Saturday
and let you guy's know how i get on,but any other suggestions wold be very welcome.
Thanks Steve.

[knackeredMk1]

Air leak is very possible. Running on and pinking are signs of running lean.

For some reason some Mk2s do make a sound very much like pinking but suffer no ill effects .

Another factor could be too high compression ratio for the petrol you are running. Very unlikely I know, but the bike I'm working on at the moment has had the head skimmed to within a thou of the engine's life . You might think of emptying the tank and putting some super unleaded through if the problem continues.

[knackeredMk1]

Going to move this post to 'Technical'.

[mr dirt lover]

hi
as i'm a new member,when you say your going to move this to tecnical where is this.
thnanks steve

[knackeredMk1]

In the section marked 'Technical' rather than 'New Members Intro'.

[fallenmikethebike]

Just South of Scunthorpe, , no not really, it's just another area of the forum, scroll down the home page to view, then click on.
Running lean sounds the most likely cause, which needs sorting PDQ.
Mike

[fallenmikethebike]

Bugger, you beat me to it.
Mike