Are SPI Pistons any good?

[RobertTrivanovic]

I feel like i've seen a post about these pistons before but couldn't find any when I tried looking for them, so sorry if this thread is already out there.

Who's running SPI pistons these days? And are they any good (reliable)? For $84.95 its a steal to rebuild my M8... But is the price to good to be true for the quality of the product?

 

[mortelec]

I put them in my last rebuild. 1000 miles and no problems.

 

[diggerdown]

Like any forged piston you need plenty of clearance between the piston and cylinder, other than that they work fine. I don't think they will last like the oem, but as good as weisco. I usually give them a little extra ring gap and a litttle extra warm up time before each ride.

 

[madsledder]

We had a couple go down with them here. ! was the wrist pin clip let go, and 2 were the top of the piston breaking off above the top ring. Maybe like said above with extra ring gap may be ok. But oen are better and not that much more money. I got mine from Oregon Trail sports last year and it was aroound $250 if i remember right and that come with top end gaskets.

 

[Phizzer]

My buddy has rebuilt multiple sleds with the SPI pistons and never had a problem. I plan on getting a set when I do mine.

 

[Snowmow]

I don't like em. Just buy oem if you can.

 

[sled_guy]

I've installed a couple of hundred sets of them in Cat, Doo, Polaris motors in the past 10 years, never had a failure that wasn't self induced. Great pistons in my opinion.

sled_guy

 

[RobertTrivanovic]

I want to buy a set but I can't afford to get a new set of pistons if these ones were to fail. Tough choice hearing mixed opinions on them.

 

[ezra]

I have rebuilt 10 with them in the last 5 yrs .
I slapped them in my old f7 1st set I used. quick and dirty job. used that yr then sold to my bud for his 16 yr old kid. well they have 5k of hard teen abuse on them no issues.
I have no prob with them. I have weighed them all and they are closser in weight more times than not than oem.
oh btw the yr I put them in my f7 the f7 was on spray prob over 12 bottels that winter. pulled nos before the kid got it but still

 

[RobertTrivanovic]

Seems like most people have no issues but the od few do, might just need to go with it and be done with it for another season till I sell the thing!

 

[DAKOTAKIDD]

I ran them on my old REV chassis and had nothing but problems with them. With that being said it was a REV and they like to blow engines. As for SPI in a Cat, I have no idea..Just my .02

 

[ezra]

what problems were piston related in your rev?

 

[DAKOTAKIDD]

The problems I had were first, the crank bearing went at 1500 miles and that caused bad bad damage almost entire engine toast including the cases. So I changed everything and put SPI's in and less than 500 miles later one side went down because the locating pin on the ring gland went and the top of the piston lost a chunk. Replaced that one and 200 miles later, the exact same thing happend top the other side. All measurement and clearances were within limits when I rebuilt it..I did notice they are very light compared to the stock BRP pistons. Then I rebuilt it and sold it. enough was enough. The REV's have a bad rep for blowing up and I guess I shouldn't have bought it in the first place..my bad..Like I mentioned above in my post, I have no experience with them in M series sleds but if I were to rebuild, I would spend the few bucks extra and replace with OEM.

 

[Rixster]

I have run them many times with no issues. Mod motors, NO2 motors, And someone above stated that they are forged, They are not (as far as i know) unless they have started build a different piston. That is the beauty of SPI pistons, they are a cheap alternative to a expensive stock cast piston.