I have just bought a commando from the USA (Colorado) and it has been fitted with small main jets ((160) the manual is a bit ambiguous can anyone suggest where I start 220s/ 230s in twin resleaved concentrics? It has a high level exhaust and pea shooters.
many thanks, David
160 main jets are the size…
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Previously phil_hannam wro…
Previously phil_hannam wrote:
160 main jets are the size associated with the smaller concentric 600 series of carbs as used on the Triumph 750 triples and othe smaller engined bikes. For example the 626 carbs were very common on such bikes. The type/size being stamped on the carb side.
What size are your carbs? They should be the 900 series such as 930 or 932. These carbs generally need a 220 main jet at least.
The 750 Commando usually had 930 carbs. The later 750 & 850 engines used the 932. But not always.
Ah yes sorry my mistake the jets are 190s so 220 will be a good place to start , many thanks
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I'd suggest it was jetted…
I'd suggest it was jetted for altitude with Colorado being mountainous. Used to run my Mk 3 850 on 180 main jets intwin 932 carbs for two decadesin Nairobi which is 4,500 feet above sea level,and was still a touch on the rich side. Now back in UK and running sweetly on 230 jets after a rebuild.
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Yes, most of Colorado is v…
Yes, most of Colorado is very mountainous. Denver, CO is called the Mile High City for good reason. Altitude is 5,280ft in old money!
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160 main jets are the size associated with the smaller concentric 600 series of carbs as used on the Triumph 750 triples and othe smaller engined bikes. For example the 626 carbs were very common on such bikes. The type/size being stamped on the carb side.
What size are your carbs? They should be the 900 series such as 930 or 932. These carbs generally need a 220 main jet at least.
The 750 Commando usually had 930 carbs. The later 750 & 850 engines used the 932. But not always.