Rebuilt carb on '04 RMZ-250 and it won't start

5 replies to this topic
  • petek

Posted November 04, 2012 - 04:43 PM


I bought a pretty clean 04. It ran but wouldn't idle when I bought it. I pulled off the carb and cleaned it out-- it was pretty clean.

Now, it won't start.. I screwed around with the idle speed djustment screw and wonder if that is my problem? I attempted to adjust the idle UP, hoping to just get it running.
I also re-adjusted the idle-air (2 1/4 turns). The previous owner put an aftermaket adjuster screw in.

Any suggestions?? I have read all of the comments about valve adjustment and plan to do that. But I want to get it at least running again first.
BTW- I've been kicking it over as suggested here(in neutral). I've also tried pop starting it in 2nd


  • airbus_a300

Posted November 05, 2012 - 07:55 PM


usually if your idle speed is set to high it becomes very difficult to kickstart the engine, you say your fuelscrew setting is set at 2 1/4 turns out from full in? also what pilot jet do you currenlty have installed? if i were you i'd check the spark plug condition and see if its dry since it can tell you if your engine is receiving at least some fuel

  • petek

Posted November 06, 2012 - 04:33 PM


Carb jets all appeared to be per the book, except the main was a 175. New spark plug, and the bike is getting spark and fuel. I've re-confirmed that the fuel screw is at 2 1/4 turns.

I noticed that the hot start plunger, wher it screws into the carb was a little goofy. The boot appeared to be poped off of the part that screws into the carb. I fixed and also adjusted the cable so that I was sure the plunger is all the way in.

I adjusted the idle setting so that the screw just touched the throttle cam, then I gave it about 1 more full turn, so that it holds the throttle only a little open. *** is this correct??? ****

NOW: If i kick it using the recommended technique, I can get it to fire and run for 5 seconds, then it will die. I found that a quick twist of the throttle while kicking will get it to bump over.

Thing is - I don't know if its carb or valves.. am I wasting my time messing with the carb and should I jump righ into the valve clearance check?


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  • Cutter3587

Posted November 06, 2012 - 05:30 PM


Check the slide, the flat plate on the slide can easily be installed upside down and it will keep the bike from starting.

  • petek

Posted November 07, 2012 - 04:29 PM


The slide looks fine, and I double checked it with the manuals.
My valves are WAY out: both intakes at 0, one exhaust at 0.024 the other at 0.014.

Are these kind of numbers normal ?? Those exhaust numbers seem crazy loose.

  • Cutter3587

Posted November 07, 2012 - 05:40 PM


the intakes are supposed be between .004"-.006" and the exhaust betwen .007" and .009".

Good luck with that bike I had one an it was easily the worst bike I ever owned. After I solved the overheating problem and the valve problem the transmission came apart. Made we want to get out of riding and buy a boat it would've been cheaper\


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