My buddy finally got around to building me some valves...they are pretty!
Hopefully this wont happen to me anymore!!!
Hopefully this wont happen to me anymore!!!
Stainless Steel Power Valves
- Thread starter sideshowBob
- Start date
wow, seen alot of damage but never a valve broke off there
shaggyzr2
Active member
What causes them to break off like that?
BETHEVIPER said:
I have broken three different valves like this over the past 5 years and not always on same cylinder.
I think it has a lot to do with my sleds mileage, riding style, and the RPM I am running at.
The valves have always broken after a very long [15+ mile] high speed , consistent 7500-8000 rpm lake or rail bed run.
Last year I pulled the cylinder head off on the trail 100+ miles from home to remove the broken piece from the cylinder so I wouldn't need a tow!
If I couldn't have gotten these SS valves I was going to remove the valves, build plugs and clutch my sled like my ported read heads.
Bob,
I am guessing you have tried new valves? There must be some fatigue in these? How many km's are we talking?
I find it hard to believe anyoencould be harder on their sled than I was on my '01. My problem was keeping the rear suspension in one piece. It kept breaking and shearing bolts off! oops.
I am guessing you have tried new valves? There must be some fatigue in these? How many km's are we talking?
I find it hard to believe anyoencould be harder on their sled than I was on my '01. My problem was keeping the rear suspension in one piece. It kept breaking and shearing bolts off! oops.
These were built by conventional machining...no CNC machine so they were very labour intensive. He built these more as a favour to me so even if he were to make more they would be of a very limited amount and may be too expensive. They were made from SS 2" round stock.
chris189 said:
One valve I broke had less then 1000 miles on it...others were higher mileage.
I believe its the sustained RPM, heat and vibration that breaks these when they are not in the fully open position. My 2002 SRX does not fully open the valves until almost 8000RPM[yes I've tried different CDIs]. I run a TEAM Tied secondary and my high speed 3/4+ throttle cruising RPM is 7600-8000 RPM...great for gas mileage.
Polaris and Cat had the same problem with their big twins until they went to steel valves.
superfan75
New member
Those SS valves are a work of art. If your friend had access to a CNC machine he could make some good money selling those. I hope they work as good as they look. Their almost to pretty to use......almost. LOL
mile9c1
New member
What happens when a valve breaks? Does it drop into the cylinder?
yesss it does ..motor chunk the valve then jam..all depend at what rpm it happend ...for me I didn't have choice to remove the head to remove the broken valve ...sucks went your far from home ..I think it a vibration effect that cause the failuremile9c1 said:
mile9c1 said:
Yes. Every time this happened to me I was coming off a long high RPM run and as I decelerated and went to idle you could here the valve banging against the piston...once I shut it down the piece of valve locked the piston so sled became unstartable.
These valve failures are the only issue I have ever had that has left me unable to ride my SRX home in over 8 years and well in excess of 20,000+++ miles.[obviously most of sled has been renewed in those years].
Yamahakid01
New member
Is that on all or just bigg bores because I could have sworn that my cylinders have stops maybe I'm wrong
On stock cylinders, there are stops that won't allow blade to enter combustion chamber. I remember testing this on my last cleaning. If I remember correctly, the sleeve itself isn't cleared away enough to allow the valve to drop thru.
You would have to break a blade off of the shaft below the stop, like in pic, to find out if the blade would slide into the cylinder...I'm willing to bet the blade would drop down enough to contact piston, even on a stock cylinder.
The power valves have the stop built into the shaft...not the blade.
The power valves have the stop built into the shaft...not the blade.
I see what your saying now after looking at your broken valve again. Yikes your right, hopefully those beautiful new valves will hold up better. It's just all that extra weight from being stainless will probably just snap the cable now lol.