i was running br8es this year.. ( the manual mentions 7es and 9 es as well )

and one of the guys I ride with is a menchanic and has 2 crm's he's saying he uses br9es's

he's on mark 1 and mark 2 tho?

The number on the spark plug relates to the heat range of the plug.

http://www.youtube.com/watch?v=LbR75wq9nmM

You might think that a 7 plug would reduce your fouling but I can't think of anyone who has used a 7 on a CRM. 9 is more usual if racing but that would probably cause more fouling.

For technical slow going a 7 might be the cure, but extended high speed work on that will qiuckly lead to a seizure.
An 8 plugb is the optimum compramise.
It's almost certainly the case that your still running rich, hence the black plugs.
Has the exhaust been decoked, ever?
Mike

yep - I repacked the end can about errm well this year anyways... ( 4 months ago perhaps? )

the DEP expansion chamber.. seemed very light and clean, and has only been on the bike 4 months ( then the rejetting )

the power valve moves freely - its a bit gunked- are they supposed to want to "float" or move to one end or other once the cables are unlinked?


interesting video.. I had no idea what the numbers meant til now.

and I thought the suggestion it was the wrong plug was a bit odd - cos I've been running those plug without issue since I got the thing in january...

I suppose I will find out that its an intermittant electrical problem right after I rebore - new piston etc...

Didn't you recently have some issues with float height?, did you reset it at sometime recently?
Would that coincide with the current problem.
Mike

fallenmikethebike wrote: Didn't you recently have some issues with float height?, did you reset it at sometime recently?
Would that coincide with the current problem.
Mike

yeah I reset it maybe 2-3 weeks ago,.. and it's done about 150 miles on that setting....

I'm gonna take the carb off this week - and check the choke is working /

I changed the o rings ( idle screw and mixture screw ) and seal for the float chamber at that time..

actually looking at the plug I swopped out about 2 months ago - that also was blackened.....

I'm using cheap as 2stroke ( havoline 2t power ) cos I ran out of nice stuff a few months ago and was forced to grab some of this from a garage forecourt...

I always used Motul semi synth and a BR8EIX, ran sweet.