OzVMX Forum
Marque Remarks => Yamaha => Topic started by: paul on May 15, 2008, 09:03:38 pm
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http://cgi.ebay.com.au/yz490-it490-yz465-38mm-power-jet-lectron-carby_W0QQitemZ330236275534QQihZ014QQcategoryZ35233QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
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What period are Lectrons allowed?
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The roadrace fraternity had them in both flatslide and roundslide format on the TZ750 Yamahas, so probably in pre-80.
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What period are Lectrons allowed?
Early Lectrons didn't have powerjet and a 36mm was fitted to the 1977 Penton 250
and so an early 36mm non-powerjet Lectron is ok for Pre 78.
This one has powerjet which is ok for Pre 80 and later.
If you are going to try Lectrons then you will need a Lectron parts supplier.
I have used FastByGast (FBG) and HTG Racing in the US and Helmut Klassen in Canada.
You will need to get a few extra rods to get the jetting right.
Best to buy them new as the quality control was bad in the past.
The powerjet is a Mikuni pilot jet. Don't go smaller than 30 or larger than 90.
Start at 60 or 70 and go down in 10s until it is close then use *5s (eg 45, 55 etc) to fine tune on the day.
The plastic float bowls distort and so you may need to get a new one to stop it leaking.
Some of the new float bowls have orings which helps and FBG sells alloy float bowl stiffeners.
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Thanks for that Info Mboddy, i've lent one to a mate to try on a yz490 down the track, but we didn't know where to start or get the rods. this may just get it us started.
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Here is a Lectron Application Chart. Thanks to Helmut.
It will give you somewhere to start.
The number is as follows:
5mmm-ssrr-r/pj
where:
5mmm (ignore this internal Lectron build number)
ss size in mm
rr-r rod
pj powerjet (mikuni emulsion style)
(http://www.spitfire.com.au/~mboddy/lectronapplicationchart0.jpg)
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What period are Lectrons allowed?
These are the availability dates of other common carbies as far as I can determine:
Mikuni TM 1983
Keihin PJ 1985
Mikuni TMX 1987
Keihin PWK 1988
Mikuni TMS 1992
Mikuni PM 1998
Keihin PWM 1999?
In your choice of carby you also want to decide based on how you ride.
Lectrons are best if you have the throttle fully open.
But more modern carbies like the Mikuni TM and Keihin PWK will be more responsive in low and mid.
Some people say that even round slide Mikunis are better than Lectrons in low to mid.
But the drag racers still like Lectrons today for their top end.
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The Lectron(and the EI) lacks the air correction circuit from Mikuni/Keihin/Delorto, that's why they sort of make top end or mid range not both well.They have a good feature that works brillianlty when incorporated into a Mikuni.
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Do we know who won it?
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Guess who just found a Lectron in a job lot purchase ;D.
Its a power jet but I've misplaced my verniers so I don't know the mm's. probably 36mm.
Could be interesting......