Feedback on 426 hard starting

Seems my bike is jetted rich on the pilot as it would take 5-10 kicks with fresh fuel+plug to start hot or cold (cold here means 59 deg F)

I live at alt 4500, and got the bike with GYTR pipe + header. The prev owner said he had it jetted, but I doubt it.

I have the hard start, 1/4 throttle stumble and high idle only.

My wife has a CRF230 that idles like a sowing machine, but my WR just wont idle low for long, so I keep having to gun it to keep it running.

As soon as time allows I will pull the carb (never done it before), clean the inside (the float chamber (?) was clean on Saturday) to see what size the pilot jet is, and buy+fit on size smaller.

Did the light blue wire conversion, but felt no real difference.

my 2c

more cents to follow

First search this forum for more information, in particular look for jetting specs and cracked throttle slide. When the carb is apart look carfully at the throttle slide for cracks. Be very carfull to get the slide reassembled correctly ( it will go in upside down) search for more info on this subject. Get the carb and all jets very clean and note all jet sizes and needle position for future adjustments (and discussion)

Make sure the valve adjustment is in specification.

If the previous owner had the bike in storage for some time start with the carburetor.

As soon as time allows I will pull the carb (never done it before), clean the inside (the float chamber (?) was clean on Saturday) to see what size the pilot jet is, and buy+fit on size smaller.

You don't have to remove the carb for main or pilot jets.

Just loosen it, and rotate it, then take the cover off the bottom of the float bowl.

It only takes minutes.

Don't know about were you are ,but i ended up using smaller pilot than standard,was hunting and stalling with standard pilot jet, a right pain.

Now it idles perfect.

Pulled the carb:

the 3 jets at the bottom were:

pj - 40

mj - 165

other jet - 65

The screw at the bottom was turned 3 times out

The jets seemed clean, but I cleaned it with carb cleaner aerosol anyway.

Also cleaned everthing else incl the slide.

Had a look at the slide, seems fine.

Changed the oil (but not filter) for the first time since I got the bike (I did 360 km).

Oil was black.

Also, I measured the amount of oil that came out, and it was approx 2000cc!!


How is that possible since all oil capacity posts indicate 1300cc - 1700cc, if I recall correctly? :thumbsup:

Well I put in 2 liters of Mobil S1 semi synthetic 15w50 which is what I used on my Honda Blackbird for 70 000 km without a single problem.

Oh, and fitted a long range Acrebis tank I got for the price of 2 liters worth of Mobil S1!!! :thumbsup:.

Bike started 3rd kick with choke.

Took it for a 6km ride, and it seems back to normal, but still idling higher as eng temp goes up.

I would still make sure the valves are in spec.

When they get tight they can cause starting problems.

Bamster, is checking the valves a tough job?

My tech skills: can do oil change, chain change, sparkplug, carb dismantle.

What tools would I need for checking valves?

All you need to check the valves is a good set of feeler gages and your standard all around motorcycle tool kit. By this I mean metric wrenches and pliers and such. Just pull the seat and tank, pull the top cover and you are in the cam area. Get the engine at TDC with the cam lobes facing away from each other and measure the valve clearances. The front cam will be exhaust and the rear is intake. You can get a pretty good idea here, and if you don't have a manual for your bike yet, you will want to get one. You can usually pick them up on E-bay pretty reasonable. But where ever you get it get one, they are invaluable and the yamaha factory manuals are very good. Hope this helps.


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