Hi all, my ds started running very badly late last year. It ran as though a jet was clogged. I tore the carb apart, had the valves adjusted and then replaced the rev box. The rev box seemed to be the problem. I took the bike out for a long ride, towards the end, it started crappin out again. What to do now, can a new rev box go bad that fast? Any ideas? Thx.....

 

Have you tried the rectifier? The CDI's on these are picky about the voltage they recieve.

 

yep. The CDI needs good voltage to fire correctly. You cannot run these bikes with a dead battery. Check that the batt is in good condition and that the rectifier is charging the battery properly. If I remmeber correctly, you should get about 13.4 - 13.8 volts at idle, and possible 14.0 14.3 volts when you rev it up. The rectifier is supposed to max out at 14.5 volts, so if you see more than 14.5, that is a problem as well.

After you run the bike to the point it's "crappy", stop, turn off the engine, and check the voltage at the battery. You should see around 13.2 volts or so. If you are seeing low 12's, then the rectifier, battery, or both are bad.

 

I'll give it a try...I hope to go riding soon. Thx....

 

what brand of box ? the procom boxes are junk ... reinstall the stock cdi and see if the problem goes away .....

 

You guessed it....procom. The original cdi box was really bad. I'm going to try what was suggested with the air filter and battery voltage...if they check out, looks like I'll be springin for a new cdi unit. Any suggestions on a decent unit, reasonably priced?

 

There are many stock good cdi boxes around cheap... as a fail safe ($50 or so used)

the big gun cdi seem to have a good following (there procom boxes reprogramed) $139

ron woods is very popular but has no rev limmit at all (kinda risky ) $300

note differant years need differant boxes... the plugs change year to year so order the right year.....

good luck...

 

Just a follow up...I upgraded the Procom box with one from Dynatek. Fired right up, rode 5 minutes and it died. No spark, lights..nothin. Found a blown 25A fuse under seat on passenger side. After replacing fuse, turned key on and have all lights. Smelled something bad and turned everything off...hope I didn't smoke new Rev box. Can't find a wiring diagram and am frustated. Any thoughts or ideas? Thx..

 

start the quad up with a digital meter on the batt ... test your dc voltage when running. it sounds like you might have a regulator problem. (overcharging) make sure when testing and you rev it ,it dont go over 14.5 volts. If it does replace the voltage regulator .. only use a stock one ,not aftermarket ones....

 

Follow that 25 amp fuse to get that problem fixed first before starting.