head work estimate and pistons for G1

Ernest Montague afm199 at earthlink.net
Thu Jun 17 19:53:27 PDT 2010


Stock pistons are the best bet.  The Spears pistons will destroy a 35k 
motor.  (Or a 4k motor). Stick with stock pistons.
Hayabusa if you need to go oversize, but you can still get .5mm 
oversize stock pistons.

It costs a small fortune to do both heads.  8 valves are $250, guides 
and installation are close to $300, labor to pull and replace the heads 
is is $300-$450 depending on how the bike comes to me.  Then a three 
angle valve job will run $300 or so.  Pistons and rings are $160-$200 
plus honing the cylinders.  At 35k you probably need seats reground. In 
other words, $1k won't do what you want.   Plus I did not cost springs.

Plus you are throwing good money after bad with a 35k SV motor. Find a 
used one if you can.

I have a set of low mileage heads I will install for around $500.


On Jun 17, 2010, at 6:03 PM, matthew patton wrote:

> I looked down the intake throat and was greeted with the sight of some 
> seriously caked up valves. I'm not interested in spending a ton of 
> money ($1000 or rather less) but I would like to get the valves and 
> springs replaced, seats checked and finished if needed and possibly 
> pistons replaced.
> How much (hours) should it take to remove the heads, replace valve 
> train parts (valves, guides, springs) and put back together?
> This is a street machine with 34,000 miles on it. It does see track 
> day duty about 5 times a year and did a 4hr endurance race though I 
> expect it's track duty to decrease significantly going forward.
> If I elect to replace pistons, what is the BOM associated with the 
> Busa option? I see Spears has a high comp kit. Any other reasonably 
> priced options?
> I realize any decent mechanic should be able to do the work but the 
> short list is Speedwerks in DE and Rick Beggs' RnR cycles in 
> Chantilly, VA. Anybody else reasonably local to DC that I should 
> consider?

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