Suzuki RG500 GAMMA

Subject: Gamma pilgrimage   part three: Stan Stephens

Stan's pricelist has already been posted some time ago by Youngie, and
when you manage to retrieve it from the 2-stroke Mailing list archives, 
you'll notice that Stephens tunes a wide variety of engines; road, off-road, 
water etc.  I can only agree with John that Stan & Co are very helpful indeed.

RG500 specific info:

Float heights on any RG500 with stock float needles should be readjusted to
19.5mm in stead of the 17mm that is recommended in the manual

Stock oil pump setting is not too rich.

The RG500   D O E S   N  O  T    H A V E   A   R E V - L I M I T E R.
(Phew, slowly things are getting clear, Arno Schobloch (Suzuki Germany)
and Stan Stephens are both absolutely sure of this, all we need to do now 
is figure out the Roserunner effect)           
    
The stage I tune is mainly about modifying the exhaust port and valve.
For stage II, the transfers are modified too, and .10 mm is taken off
the head to increase compression.
Stage III consist of more porting work, .20 off the head, and taking
6mm off the leading edge (measured at the outer radius) of the rotary 
valve. 

If a stage III engine is converted to 570 cc, heads have to be machined
to regain the original depth, since otherwise the compression would become
too high. 4 oversizes are available for a 570.

I have chosen for a stage III tune for my (500) engine, so you'll hear
from first hand what the end result is!!

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From: Rob Koopman 
Subject: Stan Stephens Stage Three Tune (RG500)

> Rob,
> So where in blazes is a long detailed report on the SS Stage 
> III???????????????????????????**&*^*&%&**^&*&*&
> Bob T.

Comin up Bob, problem is not only time (sailing weekends with, as
Lucy would put it, my pizza collection :-), etc) , but also the fine
tuning of the bike, at the moment it's not running 100%, although it
did run perfectly in an earlier stage of the break-in procedure, when
I didn't wind it open yet. If I'd have  the part-throttle response
that I had shortly after the tune, plus the high-rpm power that I've
just had a taste of at Zandvoort, THEN I'd be very impressed with the
Stan Stephens tune, but I still have to fiddle a bit to achieve this state.

I can provisionally sum things up as follows:

1) Quality of work is mostly excellent, I've seen the workshop, and it's even
a worse mess than my living room, but I felt and looked at all modified
areas of the engine that I could reach, and things feel very smooth,
and the way they modified the exhaust port and valve looks very
slick, much better matched than stock. 
An exception was one of the Swarbrick exhausts: one of them simply didn't fit
AT ALL, and I had to take it to a welder.
I also have to withhold judgement on the performance, but my
impression is that it's excellent. The extra performance seems to have
been achieved without stressing the engine a lot more: fuel
consumption has hardly changed, no overheating on a very hot day, 
smelled nice after an outing on the race track etc.

2) Price level is high, although this is a personal feeling, not based
on comparison with other tuning shops. I did notice that the Swarbrick
exhausts are quite a bit more expensive when they carry the Stephens
badge.

3) I have mixed feelings about the service. Without exeption, everyone
was very kind, forthcoming with information and helpful. But other
aspects of their service were insufficient.  Just a few examples:
- Exhausts were not in stock, in spite of promises by phone that they
would be. In the end, I had to leave the engine behind and make an
other journey to England, since the engine work could not be finished
within the time agreed.
- I had mentioned twice that I had to leave by ferry, and yet the
engine was AGAIN not ready when promised (even though this was almost
am month later, Stan's staff did do their best to correct the situation, 
and in the end I just caught the ferry.
- I have mentioned three times that I wanted my original pilot shaft
back, but they did not not supply it with the engine, and not with 
the silencers which were sent by mail later, in spite of phone calls. 
I asked a friend to pick it up, and he was told it had been binned. 
(this shaft had only two minor dents and was still in such good shape 
that they had recommended not to replace it. It's the obscenely 
expensive shaft that links the two crankshafts). 

All in all, considering their international reputation, and their
price level, the service is simply insufficient. (at least it was
so in early 1994, I don't know what has changed since then)

When I have a more accurate impression of the performance, I'll post.
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Rob Koopman ( Rob.Koopman@inter.NL.net ) ^{RG500 Index}