Rejetting Carbs after pipe install

[rickardracing]

I installed a set of Samson 29" turn outs on my 07" RSV. Should I consider rejetting the carbs?

[MikeWa]

I would consider it but I probably wouldn't do it.

Mike

[allwx]

I don't know anything about those pipes, whether they're open or heavily baffled. If they're baffled then you may need to do nothing to the carbs. If they're wide open then you probably do need to rejet. Another big factor is the elevation where you live and ride. Carbs come from the factory setup to run "OK" between sea level and about 6k feet. If you live much above 6k then you could benefit from rejet with or without new pipes.

 

Another thing to consider is your airbox. If you install very open pipes then you also need to open up the intake. This isn't very easy to do on the Venture, because of the intake design.

 

One thing you might consider doing, before you make any further mods, is to get the bike to a dyno and have it tested. That is the truest way I know to dial in the jetting. A dyno run should give you a printout that shows mixture at every rpm from idle to redline. Knowing how the carbs mix at every rpm and load tells you which jets to replace and by about how much. A good dyno operator may be able to give you specific advice on where to go. You'll need at least two runs, so it could cost a couple hundred $ but once you get it dialed in you'll know it is right as can be.

[rickardracing]

Yeah, I don't think I will be paying for dyno time anytime soon. The pipes are open, very short baffle. The bike runs great, gas mileage is at 40-42 mpg, depending on how hard I twist the throttle. I was just wondering if it was necessary or not.

[Carbon_One]

It's probably not needed. Run a few hundred to a thousand miles on it, then pull the spark plugs to see what they look like. I wouldn't do anything to the air intake either except put in a K&N filter. The bike gets plenty of air as is. If anything you could bump up the pilots one size to enrichen the bottom end a bit. Doing that will also help on those cold morning starts. That is how I have my carbs set up.

That's my

Larry

[jakester]

I run samson fishtails -- k&n filters , no rejet , runs great. If it ain't broke , don't fix it.

Bill

[twigg]

It's probably not needed. Run a few hundred to a thousand miles on it, then pull the spark plugs to see what they look like. I wouldn't do anything to the air intake either except put in a K&N filter. The bike gets plenty of air as is. If anything you could bump up the pilots one size to enrichen the bottom end a bit. Doing that will also help on those cold morning starts. That is how I have my carbs set up.

That's my

Larry

 

Yeah ... You only need to do this if you can't correctly set the Idle Mixture within about 3 1/2 turns out from a soft seat on the Idle Mixture Screw.

 

Only the correct size jet will allow this.

 

Going bigger doesn't richen the bottom end to any useful benefit ... The choke circuit does that for cold starts.

 

Usually, and it may be different for the later bikes, when free-flowing pipes are added, it is the needle, needle jet and main jet that sometimes need changing.

 

Others may know better.