Carb Jet Settings on Comer S-60
David Lloyd
Donald Kerr <don...@zetnet.co.uk> allegedly wrote:
>Hello All,
>
>At the weekend, I noticed that my son had a problem pulling out of a
>slow corner into a fast straight because other karts were noticibly
>faster at the same place. After trying a sprocket with more teeth I
>turned the low jet on the carb in a bit and hey presto - fast out of
>that corner. Now, the only problem I can see with this is that it
>would be more liable to sieze so can anyone offer some advice about
>where this low jet should be set or is there a rule of thumb or other
>method for setting it?
>
It is rumoured that there are two types of Tillotson carburettor for
the Comer S60 - an old type and a new type. Both can be equally
quick, or equally crap. The difference between the two is obvious
when you come to put them on the engine or take them off - the old
type does not have a projecting lip next to the 10mm nut you struggle
with, nearest the driver, making it far easier to put on/take off than
the new type, which is noticeably more fiddly for us ham fisters.
When using the new type, I was always told to set the bottom jet at
3/4 of a turn open, and leave it at that. All further adjustment is
made on the top jet only, by welding a small washer on to it, for the
driver to adjust as he circulates - starting at around 1/2 open.
On the old type, however, you tune it on the stand, starting with the
bottom jet about 3/4 open again. Fire the engine up, and adjust
tickover to around 4,000 rpm using the throttle stop screw. Then
start to screw the bottom jet in slowly - the engine revs will start
to increase, but as you keep screwing the bottom jet in, they will
start to slow down again as the mixture becomes too lean. Now start
screwing it out, and note where the maximum revs occur before the
engine slows down when it becomes too rich. You now know where to set
the bottom jet to get maximum revs, which is the ideal position.
However it is wise to richen it (unscrew it) about 5 degrees from this
position to prevent any seizures (which the driver can counter on the
top jet, but this takes experience), and you shouldn't now go wrong.
If in doubt - 3/4 turn. is a standard, but not always quickest.
Regards
David Lloyd
da...@davidlloyd.com
FKDAN
If you are in the Larkhall area, my main suggestion would be to ask a guy
named Dave Boyce who has many years of experience competing ( succesfully
) in the cadet class, he is at the circuit most days and has a shop at
Larkhall Autopoint situated within a mile of the track. You may have
dealt with him before , but if you havent he is generally helpful.
I have many years racing 100cc Nationally and Internationally in the World
and European Champs etc. And my main to you would be concentrate hard on
the advice given to you only be people who genuinly know what they are
talking about and have proved it on the track.
Its a tough enough game without getting bad advice..
Good luck
Dan Liddle
RR
Hi
Do you have any informations about Comer engines?
If you have the URL's about CRG, COMER, ROTAX, ITALSYSTEM, etc.
engines send me.
Thanks
Rui Ramalho
mailto:rram...@mail.quatrosi.pt
Portugal
Donald Kerr
Hello Rui,
> Do you have any informations about Comer engines?
> If you have the URL's about CRG, COMER, ROTAX, ITALSYSTEM, etc.
> engines send me.
Unfortunately not. Comer and Tillotson are not very good when it
comes to correspondance and advice etc :(
--
Bye for now,
Donald (Kerr), Glasgow, Scotland
don...@zetnet.co.uk .oOo. http://www.users.zetnet.co.uk/kerr
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