Does Vertex Piston Require Race Fuel?

[Racer_x4]

I ordered a Pro Circuit Vertex race piston and one of my friends told me that I have to use race fuel with this high performance piston. I have never heard that before, but I was wondering if maybe anyone else knows any info. about having to use race fuel with the Vertex piston? Thanks :)

 

[spanky250]

It depends on which Vertex you got. They have two lines of pistons. One is an OEM replacement that is a clone of the stock piston, and will work fine with whatever octane fuel you use with the OEM piston. The other line is a high-compression racing-only piston. Not only does it require race fuel, it won't last more than 8-10 hours of hard racing.

 

[Racer_x4]

I'm not sure which one I am getting, since the company that fixed my cylinder just gave me what they had in stock, and only told me it was a Vertex but didn't tell the type. I hope it's just the clone, even though I would like to run race fuel, but 8-10 hours isn't a very long time at all on a piston... :silly: I guess I'll see what kind it is tomorrow when it comes in. Is there a way to tell which one it is in case the piston isn't marked?

 

[marcusgunby]

I think the remark you friend is dealing with is the 00-02 cr had a very loose piston ring (large ring gap)and low volume head and when you fitted a vertex it tended to make it detonate just because it was doing a better job of holding combustion in the head.A yz doesnt have this problem.

 

[Moto Madman]

i have a Vertex in my 98 RM 250. I just got done breaking it in and it worked fine on 94 octane. I dont think its anything to worry about.

 

[Durt Cycler]

Originally posted by spanky250
It depends on which Vertex you got. They have two lines of pistons. One is an OEM replacement that is a clone of the stock piston, and will work fine with whatever octane fuel you use with the OEM piston. The other line is a high-compression racing-only piston. Not only does it require race fuel, it won't last more than 8-10 hours of hard racing.

Sorry spanky but even know you know your stuff I have to disagree with ya! :moon: . I am currently running a Vertex Race piston in my CR and I have about 20-25hrs of riding time on it and I still have a ton of compression left (180lbs) and I have no buildup on the piston past the ring (blowby). I was running VP C-12 before because I too thought I needed race fuel untill I got tired of spending $40 for 5 gallons and switch to 93/94 pump fuel. I have noticed no difference in engine noise (no knocking or pinging even at max RPMs) or basically any performance/throttle performance gain from C-12 and pump 93/94. Basically if a stock CR125 runs a compression ratio of 8.5:1 stock then how much compression can you get off a just a piston? I beleive pump 93 fuel will work good up to 11.5:1 - 12:1 compression ratios. If i'm wrong feel free to correct me :cool: .

 

[Racer_x4]

I got my piston in today and it says 'Vertex Racing Parts' and 'For Competition Use Only' and also that it will only have a life of 10 hours max :think: I didn't find anywhere on the box or the piece of paper inside that tells me that it is imperitive that I run race fuel, but someone just told me that Pro-Circuit reccomends it. I'm going to do a check and see where the closest dealership that sells the race fuel is. Anyone from the Dallas/Fort-Worth metrolplex know any dealerships that sell it? I know there has to be some down here. I wonder if Central Yamaha in Plano sells any?