82 exhaust change,do i rejet?

[nlovern]

Hi,
I was wanting to change the exhaust on my 82, their pretty rusty but quiet, was thinking of some chrome pipes with better sound, would I need to rejet since the 82 is stock very lean anyway? What size?
Thanks,
' Nathan Lovern,va

 

[5twins]

I would suggest you go one up on the mains. Totally stock BS34 equipped 650s benefit from this so if you're changing the exhaust, I think you're gonna need it.

 

[gggGary]

The mikesXS long commando system is a good choice. of a "bit" of rumble" classic looks and easy tuning.

 

[nlovern]

I would suggest you go one up on the mains. Totally stock BS34 equipped 650s benefit from this so if you're changing the exhaust, I think you're gonna need it.

what size do I go up to?
Thanks

 

[CDNTX650]

I went up from stock 132.5 to 135 on the mains only my bs34 equipped TX. I run uni foam filters with mikes Brit mufflers. I dont a ton of highway drives either and plugs would stay a bit dark for my liking (still tan, just dark), although always ran and drove great. This season ill try the Autolite plugs which apparantly are a bit hotter and clean better, especially for my driving habits.

 

[scabber]

You might not need to change jet size. On my stock 650 with mikes 1 1/2" head pipes and the short reverse cones. I put a 135 main the advice usually given. Like CDNTX650 plugs indicated being rich. Look at your plugs now. They should tell you if you are jets are right for now. With Better flowing exhaust an increase in velocity at the carb will pull more fuel without a jet change. Put them on run it. If it runs right do a plug read. Sometimes no jet change is best.

 

[CDNTX650]

Scabber, did you go back to the stock jets? Wondering if thats why my plugs are a bit darker. I dont do a ton of high rpm running so i kinda ruled it out. figured choke and shorter runs contributed to it.

 

[5twins]

It could very well be the choke use. If you check your plugs too soon after starting with the choke, you will find them black. You might try checking and lowering your float levels a tad.

 

[CDNTX650]

That was the firs thing i checked actually . They were both just.below the seam where the bowl and body meet. Used the tube method.

 

[XSLeo]

On jetting you need to let the bike tell you what it needs. In the carb guide there is a tuning section. It gives you the method to test. It gives you what to change from the results of the tests.
Basically test, make one change, test, make a change, test. Eventually you will find what works.
Leo

 

[5twins]

Yes, I'm suggesting you experiment a little and go 1mm lower than where you are now. The mains influence plug color mostly at higher speeds/RPMs. That's why you do plug chops to test them (full throttle runs, kill engine and coast to a stop). Needle, needle jet, idle circuit settings, and float height have more of an influence on plug color at lower running speeds. Are you running the Canadian needles and needle jets by any chance? They are much richer than the stock items.

 

[nlovern]

Hey,
Nathan here. My plugs always stays a light brown all over, sometimes in heat of summer will even blurble I guess you could say at low speeds out the exhaust. Been driveing it for 2 years now and plugs always stay light brown. I run 93 octane in it. Oil still light brown after 2,000 miles..
Thanks
Nathan