CX500 carb jets

J

jeroenhulk

New Member
Recently i bought my first bike, a '78 CX500.

The idea is to go the cafe-way with the bike. And i'm really looking forward to get a lot of work done on this bike the coming weeks, months (, years).
Anyhow, i have made a list of some parts i need to buy and i'm lacking the knowledge of which jets i need for the carbs.

The bike has (2) Keihin 37 A carbs, and they will be fitted with K&N air filters. The exhaust will be 2 pipes with the H-box still connected and right after the H-box an EMGO shorty muffler on each side.

Any suggestions? should i just install the new parts I mentioned above and see what will happen? I prefer to order the jets at the same time to avoid waiting and additional shipping costs.

Thanks!!

ps. hope to find time soon to start a thread for a bike build.
 
put your pods on and see how it runs.........the shorty mufflers wont affect anything. Guys are usually re jetting after dumping the Hbox and air box........the 2 are tuned to each other and when rejetting the carb its usually 90/120
 
There are some that will say keep the airbox and hbox, but personally I think the Hbox is borderline being rotten and weighs a ton, so I got rid of it and ran straight pipes to harley dyna mufflers. But I upgraded my carbs to Mikuni's 34mm........it runs sweet!
 
Thanks for the advice,
i think the h-box was replaced by another by (some) previous owner. I saw some pics of the original H box and mine is a lot smaller. I also read the H box connects the pipes so the cylinder will 'work together' more efficient, the H box makes sure pressure on both cylinders will be the same. Any thoughts about that?

First i'll use the old carbs to avoid spending all my money straight away.
 
some will say that, yes it makes them more efficient and others will say no it doesnt. Personally, I think it can work well both ways and I just didnt want a 17lb piece of rust under my bike.
Get a quality air filter with no lip on the inside that will disturb flow into the carbs......the filter slides over the carb mouth cleanly
Get some jets...it comes jetted stock with 78/112.........others are putting 90/120 when making changes to stock intake exhaust

You may need to change jets....better to be on the richer side than running lean
 
Get the motor in tip top shape first..........new cam chain, mechanical water pump seal, adjust valves, and check your rad fan (inspect for damage or cracks, have been know to explode in pieces.

Then do your stuff to it......if you need info on these things just let me know
 
Thanks again for the advice,
Working on all those point already, rad fan was missing on this bike, so I'm going for the e-van conversion maybe.

Cheers.
 
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