numbers on icm / cdi

[benny hedges]

assistance please!

yesterday, in an attempt to cure an annoying low rpm misfire, after trying everything else ie new plugs, cleaned air filter, messed with carbs, checked balance, cleaned air jets, checked diaphragms, air cut-off valve, new rubbers, checked vac relief valves and hoses, different pilots, mixture screw, mains, needle setting etc, did everything i could think could cause it, with no difference so i concluded it was not a fuelling issue.

as a last resort, i swapped my icm & cdi for a spare set off an older storm.
so later, on test, fires up the same but tickover was noticeably higher, over 2k and i had to turn it down...
instantly noticed a LOT more pull at low rpm and was surprised how quick it hit the limiter
(always gets there in every gear but this is different!)

the numbers on the cdi were identical (the smaller unit under the tail)
the number on my original icm (larger 16 pin unit) is MBBA ED 001M 9018 - thats off a 2001.
the number on the new one is MBBA ED 001A 8018 - off a '97 donor.

so i was wondering... that doesn't look like a serial number.... what difference is there.
does the older one have different advance settings or something - or does the cdi put out a fatter spark?
usually ive found that cdi's etc either work or they dont work, you will rarely see an intermittent or rpm specific fault?

the misfire has gone btw and i can now ride the bike in any gear at 20 - 30 mph, whereas before it was chugging and snatching the chain.

[tony.mon]

Haven't heard about any differences at all re the control electronics on these, but if there is any it will be to the advance curve, what advance for what revs.

Maybe you had one of the limited French ones!


But it may just be a better or cleaner connection once the unit was swapped out.

[benny hedges]

But it may just be a better or cleaner connection once the unit was swapped out.

doubt its that as i've had the original one off already a few times looking for corroded connections... especially after my chain snapping incident as it smashed the undertray under the icm so thought that couldve damaged the wiring?
possibly couldve damaged the unit by shocking it, but doubtfull as it's encapsulated and there is no obvious sign of external damage?

definately pulls stronger though - it actually scared me yesterday for the first time lol!

[tony.mon]

We could swap them over at the Bulldog and see if it makes any difference, if you want?

[darkember]

Tony one thing you should do would be to put the old one back in & see if you can recreate the issue just to reconfirm it was that unit & not something freaky & delayed after all the other work you did on the fueling side.