Yamaha TRX850 Enthusiasts Forum

Hi all,
Im after borrowing a CDI for my trx to see if it solves a problem that i'm having with the ignition timing.
I'm near gloucester, if it fixes the problem i will be after buying one.
Cheers, Jay

I've got a '96 import (4NX) one if that's any use? It'll plug in to your standard UK loom and make the engine run, if that's all you want it to do.

yeah all i'm after trying is to see if it is the electronic advance unit within the CDI on mine that is playing up.
When opening the throttle the power picks up but then it dies down just like the ignition is retarding.
Would be great Kayla if i could give it a go please. Gotta pop to germany for a couple of weeks on friday, can i send you a PM towards the end of the month?

If i find the problem i'll stick it in the tech. probs. section in case others have a similar prob.

Also, if there is anyone around gloucester area got one that would help out with the postage.

Cheers, Jay

what about if you do the mod to the unit you have now on the bike and just set the ignition to full advance.. takes five minutes to do couple of wires and 2small female blade terminals and a round terminal to fit your battery.

Hi Jay,

Yes, of course, just send a PM if you need it. It won't pull past 7000 without a derestrictor box though, but it will run your engine.

You could always try Cobba's suggestion though

does that stick it on full permanent advance so it wont retard itself once flat out?
jay.

No advance OR retard curve is applied to the timing, it becomes fixed at full advance if you do the CDI mod.

what do i need to do to that then?
i think this thread should be moved to the tech probs page now
cheers, jay.

You`ll find the details on several threads but recently it`s been posted again on this one:

http://trx850.motomaniac.net/forum/view ... it=CDI+mod

perfect, will give that a go before anything else.
thanks all. jay.

biker_jay wrote:i think this thread should be moved to the tech probs page now
cheers, jay.

Done

Ok, taken some time to get round to trying it but i have tried the cdi mod and still getting the running problem. I do think its the advance part of the cdi broken down.
Going to stick the strobe on it on the weekend.
Jay

just want to confirm i've done the mod right with people that have done it. As you look at the cdi connections, right connection (smaller one), earth the top left and top middle 'tags' (cant think of the word atm). Pretty sure this is the right thing.
Jay.

ok, so i got a new cdi and still have the same problem.
I think the next thing to try is have the carbs cleaned properly. I know someone with a ultrasonic cleaner.
Apart from that, anyone got any other ideas?

Just to be clear what is happening.
1st thing, when cruising along mid throttle the motor feels like its hesitating a little. Wondering if its too rich?
Only really noticeable when in top gear.
2nd thing, cruising along (4th or 5th gear most noticeable) any revs, shut the throttle off then just crack it open. The power comes on but then dies off and hesitantly comes back on.

I thought i had got rid of it once but when i turned on the reserve part of the tank, it started again. Thats what makes me think carbs.

Jay

It could be water in the fuel, or crud in the carbs. I had a similar problem that only showed at or near full throttle and running a capful of acetone through with the fuel cleared it up.