Making Powervalves

[corndog]

Hi guys, I have owned a 99 RMX 250 for over a year now. I Really like the bike, cheap to buy, good comfort for the trails and better on a MotoX than my ability, but, I am constantly worried about the powervalves failing, it happend to the previous owner and cost him £600 to fix, and he did the all the spannering!!!

It might be possible for me to have some of the powervalve components replaced by items a machined by a colleague from a stronger material, for not too much money. I have acces to some EN24T bar (that was an offcut from parts we made for the the thrust SSC car, we were a minor sponsor) would this be suitable. I like this material as it is strong but not brittle. I appreciate the thermal expansion differences and are a bit heavier compared to the hard anodized alloy the Suzuki parts are, and im not happy about having Titanium valves made, im sure the Ti will wear the powervalve bores in double quick time. Anyones 2cents appreciated

 

[corndog]

Oops, thats the old steel number system. EN24T is 817M40T in modern speak

 

[chewy]

Mate

I wish !!! I just paid $AU340 for a new PV today on my 98RMX. I pulled down the topend for a look. Went to the local dealer to get the 3 screws holding it in place impacted out and the valve come out in a few pieces too many!

I thought of the same thing today, they don't look that difficult to make with a fair amount of engineering knowledge and equipment.

Good luck if you decide to go on with it and let us know how you go. You could sell plenty in Australia. Common bikes, Common failure.

 

[corndog]

Im having problems getting my prototype department to do the work, Ive called in my favours getting parts for my Ducati 900ss made. I have some more options avalible so stay tuned!

 

[PedroMx]

I've made them from 7075t6 aluminum alloy also for RM, not the best alloy but has 4 mx seasons now no problem.
good luck
Pedro

 

[cujet]

Aluminum is not a good chioce for powervalves as the heat and vibration will fatigue it over time. that is a fact of life with aluminum. Stainless steel of nearly any decent quality will do quite well. As will any "quality" steel. I have stainless powervalves in my Husky. They hold up well, however they do wear the aluminum cylinder. Using leaded fuel has reduced this wear to nil.

Chris

 

[Jbailey]

Replacment power valves

I've been told that a US 1993 RM250 2 peace power valve works. It would seem smarter to just change.

Does anyone know which 2 peice power valve works?

 

[corndog]

Two piece powervalve sounds a good idea, but I will lose the lovely tractable power of the RMX. things are going slower than I would like in making the power valves as i am still sorting my road bike, the fork legs needed rechroming and that is taking some time to sort out. I hope to be having a look at the Suzuki next month.

 

[edstoll]

Has anyone sorted out the RMX powervalve situation? What RM250 power valves will fit in My 1998 RMX cylinder?