Max revs when starting up.

[Todd5774]

Right..

Got a 02 ec300 bike has been fine until today, when to start the bike it it went to max revs straight away with out touching the throttle.

Ok.. Stuck throttle cable or slide? Took the carb apart and cleaned everything up, looked like there was abit of moisture in there, so drained the tank and flushed then added new fuel, made sure the throttle cable isnt binding or stuck, thats all fine put it all back together and same problem still..

Can the CDI affect the throttle at all?

Can the slide be not returning? but then im not touching the throttle so it shouldnt be moving anyway?

I'm at my wits end, and out of ideas i'm supposed to be racing tomorrow!

Anyone have any ideas?

 

[iajim]

It sounds like the slide is hung up in the carb. does it gain revs over a minute or is it more like one second? If it's only a second it almost has to be a hung up slide. This was common old Yamaha enduros. Start with the carb/ slide, after you're certain it's correctly assembled and the engine shut off, try twisting open the throttle and letting it snap closed on it's own. If the throttle won't quickly close on it's own, keep looking into the slide, the cable and the throttle barrel on the end of the handlebar. Let us know what you find. Jim

 

[Todd5774]

Well spent all day fiddling with the carb, with no joy so decided to move on to the throttle housing/barrel, when i took the cable completley out of the hosing and started the bike with a bit of wiggling of the cable got the revs to drop right down to idle, but when i put the cable back into the housing it revved out straight away. Plus the throttle didnt really snap closed more of a gradual shut off.

Took the cable right off the bike and stripped the outer sheath away and could see a slight kink in the cable about 5" from the grip end of the cable, so bent it back abit and reasembled and it seems alot better although it still grabs abit, so have ordered a new cable. So will see if that does the trick, also decided to clean the housing and tube as they were quite gunked up.

I'm wondering if i caused all the problems when in a fit of cleaning decided to lube the cable last week? Dont normally do that as prefer to run them dry and replace once a year, but after riding in the snow felt a bit of tlc might work..

I think in future i'l adopt the normal method of cleaning in that if its not broke leave it alone!!

While im at it is it worth changing the slide? Can you buy them seperately? Or would people recommend changing the spring in the carb? The bike is an 02 so i guess parts are starting to wear out now so a overhaul would'nt hurt.

Has anybody got any part, no's for the slide/spring? 02 ec300.

Ta

 

[Diddel]

I'll post the suggestion of a defective ignition side crank seal for future use/searches.

 

[stay_upright]

I'd recommend buying a spring for piece of mind if nothing else - some people say that they do weaken/shorten and they should be cheap. I've not replaced my 05 spring as the throttle always snaps closed nicely and I check it fairly regularly out of habit.

I've never heard of anyone replacing a slide due to wear and I'd only replace/change carb parts for jetting issues or improvements. If you wanted to do that the best thing to do IMHO is buy the JD jetting spreadsheet, a couple of different needles, a couple of different pilot jets and a couple of different main jets and go and experiment. Plus check your float height first.