Hi-Perf longevity

[Pushrod]

I had the good fortune to purchase a modified street bike, runs great, no problems at all. But I am curious...

It's a VTR 1000 F with Moriwaki pistons, cams, TBR cans and a dyno'ed jet kit. This ten year old bike keeps up with the local sporty boys with ease. The question is; do sport mods in a motor decrease expected life? Does anyone out there have long term experience on a modified bike to relate?

Having removed the stickers from the bodywork it's fun to be asked, "What IS that?"

 

[Haket]

Sure it does, more power = more wear. However imho how much the rider trashes the bike and how well he/she maintains it will have considerably more effect.

 

[396]

Depends on how "modified" it is. A all out race engine may very well have a shorter life span than a stock motor. If it spins life at the limit all the time, then plan on a shorter life span. If it is a mild build, than it may last just as long as a stocker.

 

[Burning1]

Most of those engine mods achieve higher power by re-tuning the engine for a better breathing and fuel mixture. I don't expect any of them are aggressive enough to noticeably effect your engine longevity, and I fully expect the bike to be worthless before the engine falls apart.

I suspect you may see slightly increased chain, tire, and brake wear though. :thumbup

 

[afm199]

Yes. If the pistons increase the Compresson ratio more than a half point or so. Every HP you add takes away motor life. It just is a matter of degree. Adding 15 hp to a 100 hp motor is no big deal. Adding 15 hp to a 60 Hp motor will definitely shorten motor life.

 

[Ironbutt]

This is up for great debate..

At this point all I think the difference is, is that you have to wrench on it more than a stock machine. I mean, little things that can turn big happen quicker. So as long as it's built correctly and maintained like you would maintain a motor that you just dropped a few grand into.. it should be okay..

Case in point: My XR, I got it hopped up but it was built wrong and the PO blew it up and then fixed it without finding the root cause and it blew up again, on me.

So then I had to figure out what happened and the whole disassembly and parts sourceing took much longer that it should have.. Runs great now.. Then somthing unrelated broke.. and there it sits.. untill I get the motivation to take it all back apart again. It's a project..

Personally I think working on it is half the fun of riding it but if it were my daily rider.. I'd have dumped it long ago.

 

[afm199]

Big twins are customarily hard on cranks. When you bump up compression you are asking for trouble.

 

[396]

Again, it just depends on how far you go. You can have the best of parts and the best builders and it still breaks or wears out quicker if it is built and used to the limit. Case in point:

Any of the racing you see on TV, whether, it be cars or bikes, the quickest of the quick and fastest of the fast are constantly being torn or blown apart. Speed cost and that is the price you pay.

Knock it back a few notches and a mild build can last a long time.