ok either i am really stupid[img]i/expressions/face-icon-small-confused.gif[/img] or this has no fix my trailboss still backfires through the carb and my freind says my cdi is bad but before i pay 230 dollars on a new one
i wanted to ask could crank seals be doing this too because they are a helluva
lot cheaper and they are as far as i know 19 years old.and how can u check them
thanks in advance.

 

What model of Boss do you have?

You must be getting a price on the cdi from a dealer.

Ebay has ones for 2 stokes for under 100 bucks. Those are new performance ones at that.

I got a working used one for my 4 stroke Boss for under 50 bucks from ebay as well.

But, I'd check the carb out before I bought a new cdi. Check the jetting and make sure there aren't any cracks in the intake tubes too.

 

its a 89 two stroke 250,and we checked the carb its perfect and yes that was dealer price but i will keep ebay in mind but is there a way to check the seals?
thanks again

 

Maybe someone else knows on that. Only thing I can think of is a visual inspection, and at that point, you're there, might as well change them.

Don't know if a leakdown test would work for that.

 

start it up..STAND BACK!!..spray carb clean ay the seals if it revs up is got a leak..MIND YOU THIS IS DANGEROUS AND YOU COULD BE A FIRE BALL..but his is how i check for vacume leaks ..its not too safe but works great..i have never known anybody to get hurt from this BUT SOMEBODY ALWAYS KNOWS SOMEBODY.. you will have to remove your pull start assembly and belt cover to gain a place to spray from to get the seals.. my guess is thery are shot..mine were and now she runs great !!

 

ok i will try this with a firejacket on (right...[img]i/expressions/face-icon-small-wink.gif[/img]when i get it running long enough because it backfires and then dies is this normal if seals are bad?

 

if the seals are leaking its running lean..whats your plug tell ya!

 

the plug looks good actually.And if i gotta take the recoil off to spray the seal AND have it runnin how would i do this u need that for either method of startin on mine
the recoil holds the electric starter in place.

 

The most common seal to go out is the output seal. That is on the clutch side, spray carb and choke cleaner on the back side off the primary clutch while it is idling. If the rpm's change, the seal is bad. Doc

 

YA ,kinda forgot about the bendix on that..i had a 91 tb 4x4 and had to replace BOTH the crank seals and also had to replace them on my wifes 99 tb..20.00 and a 12pk no big deal..