SV Rebuild

[Dawn]

After two full racing seasons on the stock SV, it is time to rebuild the motor.  I am looking for any helpful hints, do's or don'ts, and tricks that any one may have had with their own SV.

Thanks in advance....

Dawn   ;)

[Nate R]

How "Toasted" is the motor? Are you rebuilding based on loss of HP, or just to be safe? Is it drinking oil?

I guess my question is: What factors do YOU consider in questioning whether it's time for a rebuild?

Nate

[Dawn]

How "Toasted" is the motor? Are you rebuilding based on loss of HP, or just to be safe? Is it drinking oil?

I guess my question is: What factors do YOU consider in questioning whether it's time for a rebuild?

Nate

The motor is not toasted and is still extremly reliable.  It is not drinking oil and nothing indicates that we should tear it down and rebuild it.

However, with two years of racing (one with the previous owner and one with us), we feel that it would be a good idea to go through the motor for a couple of reasons.  One, just to be on the safe side, checking out the bearings, rings, valves, cams and cam chain tensioners.  Second, the supersport rules allow for a 1mm overbore...  So why not see if we can get a few more HP.

Dawn   :)

[roadracer797]

Dawn
Do you remember what happened to my 600 well the motor decided to expire and it was because in was milled out making it less reliable, my advice would to just push as much hp out of it you can with out milling. Unless you like spending money on a new motor. I know what you mean by wanting to run with the faster sv's I too want to. But ultimately it is up to you what you want to do.
Craig

[Super Dave]

I'n sure that you've got to have some wear on the SV by now.  Probably not a bad idea to check it all out just for maintenance.  The valve seats are probably pounded a bit.  As for over bore, you can gain some HP, but you'll usually sacrifice a bit of torque.  

If you don't have to bore it out, just re ring it and you should be good with some good consistent prep and maintenance.

[CCS424]

You might want to consider undercutting and or backcutting the tranny while you have the motor torn down. It is a notorious weak spot with the SV.

Wayne
#424

[Super Dave]

Did you have problems with yours?  If so, what oil were you using?

Having that kind of work done can be scary.  Some people that claim to know how to do it often don't and wreck the transmissions.  And there are differences between having it done for a drag bike and a road racer.

Did you have yours done, and, if so, by whom?

[CCS424]

I had mine under and back cut by Fast by Gast. It was expensive, but they did a fantastic job. I don't know how I ever rode the bike without it. Each gear engages with authority and no more false neutrals or popping out of gear.

I don't have the info here at the house, but they are in New York or Jersey if I remember correctly.

Wayne

[CCS424]

I did have alot of problems. It started with popping out of lower gears, progressed to losing fifth and sixth. I'm running Mobil 1 - 10W40.

Wayne

[Super Dave]

Mobile 1 seems to be a good oil.

However...

Back in the early 90's, we dyno tested some Mobile 1 and gained some HP.  Later that motor ran primarily with Mobile 1 and when it got torn down it had funny wear marks on the cam cam journals, as I remember.  I didn't look at the rest of the motor, but I remember that.  

Might be relevant, might not.

[schpreck]

I used to use Mobile 1 too, but then tried Motul.  It's good for 1-2 HP over the Mobil 1, even!

[tshort]

FWIW, there's a downloadable shop manual available here:  http://www.socalsvriders.com/download.php?op=viewdownload&cid=2

They are .pdf files, and appear to be '99 vintage.  Don't think things have changed much up to '02, but for motor rebuild could be wrong there.  They do provide a step by step set of info on rebuilding the engine.  Might be worth a look if you don't already have shop manuals.  Good luck.