Custom/Hybrid Billet engines blowing up??

[Seanc]

Not necessarily, if those strokers are pump gas motors on stock ignitions they are not being stressed more than a sea doo that has a 12 year old kid holding it wide open from cold start until dark....

you and i are not talking about the same stress. yes holding it wide open is stressful on an engine. im talking about the forces on the wrist pins and all the bearings being much more in a stroker due to higher piston speeds and the rods pulling on the pistons at a much higher angle than a factory stroke crank shaft.

 

[GIL]

Who runs cheap oil in a billet engine? That would be stupid!!!

 

[shawn_NJ]

I had my 865 backfire about 3-5times on startup, and try firing backwards..... Once bad enough to blow up a waterbox. But my wiseco wristpin bearings looked perfect, and thats after about 100hrs+ of use. Unfortunately my 100hr old OEM crank had 2 bearings that were noisy/ticking when spun, with the races starting to come apart. The ski was never sunk and never had water in the motor. So far ski has not backfired after the total rebuild. I got lucky that I was worried about the wrist pin bearings, and opened the motor up to replace them. But I think the moral of the story is that you have to inspect these high dollar motors more then a 701.

 

[steve-uk]

ignition is def not the place to be looking for these backfires, ive been having a backfire on my SS 865, have replaced the brain, double check TDC and timing etc, no difference, and i also took some phone calls from people having the same backfire issues with all different levels and brands of ignition

ive changed the pop off on my carbs and down jetted, will be water testing tonight

 

[DAG]

For starters, it doesn't come with wrist pin bearings that this thread is talking about.

That exactly my question, so what’s the difference between the 2 wristpins? How can one visually or dimensionally tell which wristpin bearing they have?

 

[BruceSki]

Those seadoo wrist pins have a ton more bearing area and way less plastic "cage" area. Hopefully they last a full season for me this time.

 

[QJS]

That exactly my question, so what’s the difference between the 2 wristpins? How can one visually or dimensionally tell which wristpin bearing they have?

The Xscream and sea doo pistons use 21mm pins with the same O/D wrist pin bearing as Yamaha which use 20mm pins.
Chris.

 

[Christian_83]

Dosent Xscream engines allso use Wiseco pistons (Honda CR500) pistons for their engines? I mean, dosent the Xscream and DASA engines use same pistons? And therefore same wristpin bearings?
Does anyone have some pictures of these cageless seadoo, and maby wiseco, OEM and Seadoo so one can tell the diffrence?

 

[shawn_NJ]

Dosent Xscream engines allso use Wiseco pistons (Honda CR500) pistons for their engines? I mean, dosent the Xscream and DASA engines use same pistons? And therefore same wristpin bearings?
Does anyone have some pictures of these cageless seadoo, and maby wiseco, OEM and Seadoo so one can tell the diffrence?

I believe the XS pistons are custom Wiesco's (not CR500). They come with XScream stamped on the box. The XS Wiseco bearing does not look very different from a stocker. The seadoo cageless are shipped in 2 plastic sleeves (inner and outer) that hold them in place. They are literally just a bunch of loose roller pins with 2 thrust washers.. You cannot remove them once installed without using the plastic shipping sleeves to retain them. Otherwise you will just have a pile of rollers when you remove the piston.

 

[JetManiac]

Dosent Xscream engines allso use Wiseco pistons (Honda CR500) pistons for their engines? I mean, dosent the Xscream and DASA engines use same pistons? And therefore same wristpin bearings?
Does anyone have some pictures of these cageless seadoo, and maby wiseco, OEM and Seadoo so one can tell the diffrence?

No, xscream billet motors use custom designed XS Wiseco pistons. Their stock stroke piston is the same weight as an oem cast piston.

 

[Kawastyler]

A little bit offtopic, but i had a discussion with a friend weeks ago about smallendbearing on 760er 62t . I allways use the oem washers on pin but he say is not needed???
But he use other bearings i dont know...... Cr500, 6m6???

Somebody knows more about it because i build on a engine at moment and have to order parts.


Thanks, Andy

 

[QJS]

A little bit offtopic, but i had a discussion with a friend weeks ago about smallendbearing on 760er 62t . I allways use the oem washers on pin but he say is not needed???
But he use other bearings i dont know...... Cr500, 6m6???

Somebody knows more about it because i build on a engine at moment and have to order parts.Thanks, Andy

Bin the washers and use 6m6 650 yam bearings....Standard practice.
Chris.

 

[Kawastyler]

Bin the washers and use 6m6 650 yam bearings....Standard practice.
Chris.

Thanks, what is the difference in 6m6 and 62t????

Prox ordernumber is the same:-(((((


Andy

 

[Matt_E]

The OEM 6M6 bearings are wider and do not need thrust washers.

 

[Cannibal]

I remember using Wiseco Small Pin Kawi bearings on a Yamaha engine with no thrust washer as well.

 

[BombThreat]

Who runs cheap oil in a billet engine? That would be stupid!!!

heh heh heh...

 

[BruceSki]

I remember using Wiseco Small Pin Kawi bearings on a Yamaha engine with no thrust washer as well.

Just put them in my 771.