Wiseco Piston longevity ???

[atgreg]

Hi All,

whats the consesus on the longevity of the 82mm Wiseco piston & rings ??

The reason i ask is that I fitted a pair to my Africa twin 750, they make a 1mm OS on the AT and I had to machine the skirts so they wouldn't hit the At crank. The clearances specified for the pistons were about twice the standard Honda.

Initially the 1mm OS and higher compression ratio were greaty with a big boost in power over the whole rev range but after 45,000km the engine was using so much oil I had to replace it with my standard spare engine.

Is this sort of thing usual when you fit the pistons to a Hawk ?? . I havent pulled the engine apart yet to check whats worn either the pistons and or rings.

I'd be interested in hearing any of your experiences with a lot of miles in your Hawk engines.

thanks

Greg

[tkm433]

Re: Wiseco Piston longevity ???

Hi All,

whats the consesus on the longevity of the 82mm Wiseco piston & rings ??

The reason i ask is that I fitted a pair to my Africa twin 750, they make a 1mm OS on the AT and I had to machine the skirts so they wouldn't hit the At crank. The clearances specified for the pistons were about twice the standard Honda.

Initially the 1mm OS and higher compression ratio were greaty with a big boost in power over the whole rev range but after 45,000km the engine was using so much oil I had to replace it with my standard spare engine.

Is this sort of thing usual when you fit the pistons to a Hawk ?? . I havent pulled the engine apart yet to check whats worn either the pistons and or rings.

I'd be interested in hearing any of your experiences with a lot of miles in your Hawk engines.

thanks

Greg

If you machined the cyclinders to Wiseco Specs and you let the motor warm up before yopu ring the hell out of the bike they will last forever.

The most common mistake with Wiseco pistons comes into play when the machine shop machines the cylinders for oem case pistons and you use forged pitons.

If you machine shop will machine cylinders without the pistons in their hands at the time of them doing the work find another machine shop.

As you know the forged Wiseco pistons require a loser fit than an oem cast piston.

[atgreg]

we had the pistons in hand and bored to the correct clearances, Im just surprised that after 45,000km (30,000 miles ) the bike was using so much oil. I havent pulled the top end of to check it yet as Im not desperate as I have the spare engine in the bike.

I guess Im looking for info as to what the normal service life is of the Wiseco rings / pistons. If I replace the rings , will they be stuffed after a similar KM.

Obviously Ive been spoiled by the standard engine which did 190,000km before needing rings

[NT696]

FWIW:
Ive got the Wiseco 700cc pistons in mine with 25K kms on them with no issues at all. The cylinders were bored with 0.002" clearance. No oil burning, and great compression.

[jensen]

To atgreg; I think you have to just replace the rings with the new type. (a rumour says that they are the same as Suzuki ) Standard japanese stuf so that should be fine. On the other hand my experience with single cylinders bikes is that there pistons and rings are done after apx 40,000km, but they also have a bigger bore, so!!