Swapping SM wheels onto WR426

Hi All

1st post so here we go.

I have a YZ250 (Yes 2 stroke) SM which is street legal and a street Legal WR426 with MX tyres on it. I have a spare set of MX wheels and tyres for the YZ. The YZ is rather impracticle for touring around mainly for the petrol problem.

So. I am going to put the YZ MX wheels back on the YZ, and want to put the SM wheels on the WR. To be honest looking at some of the WR426 SM conversions, it can turn out quite stunning !.

The question is:

Can I put the SM wheels straight on the WR without any different parts or modifications ?

Both bikes have standard brake systems, but the SM wheels have been upgraded with new discs.







As with most bikers, impatience got the better of me, and with advice from elsewhere I went ahead. Both bikes now have swapped wheels and all looks ok. Due to the setting of the sun the test drive will have to wait until tomorrow, not that I can't ride in the dark but that I ain't fitted the lights as yet.......plus I'm knackered.

Piccies as below and hopefully for future ref that this can be achieved.





Picci in the grim light of day. Test drive in 5 :doh:



Welcome to what is fast becoming a blog rather than a thread :doh: (please join in in you feel the need)

The test went brilliant, it drives like a dream. Hugs the bends and opens up nicely.

One slight problem though.

It seems to be misfiring once I hit top gear and open up. It coughs about every couple of seconds and then carries on again. Seems to be 1/2 to full throttle and if I go lower than this its not a problem. It then starts to affect lower gears. Its as if there's not enough fuel getting through. I lowered the needle from 4 to 3, upon advisement, but it doesn't make any difference whatsoever.

Any thoughts would be appreciated ?



Hmmm, wonder if the 426's had the TPS stutter problem? Maybe try unplugging the TPS and taking it for a spin. If it's like the new models, there should be a three prong grey plug under the gas tank that you can just unplug. Someone correct me if I'm wrong. I know the WR's are notorious for this. Mine does the exact same thing when steady cruising, it's not so noticeable while off-road. I can unplug mine and the stutter/missfire goes away. You may sacrifice a little low end power, but for the road cruising it will be well worth it.

Cheers for that. I unhooked the TPS and took it for a raz. Unfortunately it made no difference to the stutter and has now gained a bit of a backfire when I throttle off.........bugger

God. This is turning into a bleedin saga. Another question.....From a small patch of oil on the garage floor I have located an oil leak from the breather pipe as per number 22 or 23 on the drawing as below. Not a problem if its meant to be, but it is a problem when on the road as the leak then goes onto the SM tyres.....and at high speed, having my own oil slick chasing me around is a little worrying. Any ideas why I may be leaking from these ?


Have you turned the bike over lately? Is the oil level correct and not to full?

As for the other problem, if unplugging the TPS, or adjusting it to specs doesn't correct the problem, then you may want to check all electrical components, make sure they are clean and fitted right, even check the gas tank vent, and lastly it could still be a jetting problem. Check float height, and maybe give the carb a good cleaning.

Hopefully someone who knows more about the 426's will chime in.

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