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willshooter3
04-26-2016, 8:34 AM
Working on an 85 Honda Vt500c. Pulled the carb, filthy-cleaned it up. Now I am wondering about rejetting it. I have taken the power box off the exhaust and intend to run the pipes two into one and then into a fish tail-no baffles.
That said, any idea on what jets to use?
Thanks in advance.

Westboundbiker
04-26-2016, 11:27 AM
Really doubt anyone will know exactly what sizes you need. Order the next 5 sizes up on each, and try each one, see how your power is affected.

Here are some links that should help you better understand what needs to be changed:

http://www.caferacer.net/forum/attac...-jet-chart.jpg
http://kawtriple.com/mraxl/carb/jettingeffects.jpg
http://www.jackbhart.com/firefly/bing2.jpg
http://www.gadgetjq.com/keihin_tuningparts.jpg


http://www.iwt.com.au/mikunicarb.htm
http://www.mikuni.com/tg_poor_mid_range.html

WarMullet
04-26-2016, 4:37 PM
Not sure if this has any relevance seeing as you are adjusting for exhaust, but I've been doing a bunch of reading into adjusting for ethanol in the fuel too. More or less I'm getting the impression that making your fuel air a little richer helps alleviate those types of problems. I know my bike was lean popping like a sombich. If I'm dolling out misinformation, I'm sure someone here will correct me.

sandmanred
04-27-2016, 5:11 AM
Working on an 85 Honda Vt500c. Pulled the carb, filthy-cleaned it up. Now I am wondering about rejetting it. I have taken the power box off the exhaust and intend to run the pipes two into one and then into a fish tail-no baffles.
That said, any idea on what jets to use?
Thanks in advance.

I did more or less the same thing, got rid of the air box and built custom pipes on a Honda 250. I had found a website that sells jet kits and based on your model and what you did to it will select a jet kit. But now my CRS kicked in and I can't remember the name of the site. When you make it easier for air to get our out you have go up in jet size. So one strategy is just to keep drilling out the jets you have to tune the system. I don't have experience with this but I'm told it works. The risk in just leaving the stock jets with a way more open intake and exhaust that it will run way too lean. You can scorch engine parts if you run too hot too long. Just watch the color of your plugs; white is lean, tan is good, black is rich.

I decided to run small baffles instead. I made them too restrictive to start so I was on the rich side. I've been drilling them out to bring the plugs out of the black. Running too rich maybe robs some power but I don't think will do any long term damage. Here's what it sounds like.

https://www.youtube.com/watch?v=u4U-TkVos1I

Sky
04-27-2016, 6:02 AM
Don't forget you can shim needles too.
Best thing is to get a Dynojet kit.

Sharkboy
04-28-2016, 2:05 AM
I got a kit from a company called sigma6 I think was there name . Provide them all info i.e. Model of bike ,if your running pods,what type of pipes and where you live and they send you a kit suited with detailed instructions.I installed on my cb400t but haven't run it yet so can't say how good it is. I should be starting my bike in the next couple of weeks so will have more info then