Blue Pipes Times 3

[wingnut]

Some time back best buddy bought a 79 750 Special. Nice bike and at a good price. Needed the carbs cleaned, a new starter and tires. All done and it runs great. The PO had drilled out the ends of the mufflers and it sounded great but was to noisey for my buddy and me. We cut 2 stainless steel disks to fit over the drilled out section leaving a stock looking muffler with stock outlet holes in the centers. He has put about 100 miles on it and the pipes are turning blue at the head. Running to rich? What size jets were stock in the 750s? When we had the carbs apart I didn’t look at the jet size and just assumied they were stock as the rest of the bike was. I’ve never had this problem with a bike before so looking for some direction. Thanks

[TopCatGr58]

Hey Steve,

Here's the specs from the parts fiche:

Standard:
17 620-14231-26-A0 JET, MAIN (#130) U.S.A. ONLY 3
17 620-14231-25-00 JET, MAIN (#125) CANADA ONLY 4
17 620-14231-26-00 JET, MAIN (#130) U. R. CANADA ONLY STD 3
17 620-14231-28-00 JET, MAIN (#140) CANADA ONLY

Special 130 only!

T.C.

[trbig]

You can do a search, but I believe it was stated in here before, that if the pipes are blued for only a short distance out from the head... not much beyond the first bend of the pipe, that it was a lean condition (Head getting too hot). If the blueing goes all the way down the pipe and even maybe makes the second bend going towrds the back, that it was a rich condition (Fuel burning in the pipe). Your quickest and best bet... probably cheapest in the long run... would be to get a Colortune plug to check for sure. It would take all the guess-work out of it.


Tod

[wingnut]

Thanks Folks. We put the color tune on it last night. All three now adjusted to a nice cobalt blue. Center cylinder was running rich according to the color which was also the pipe blueing the worst. After color tune we threw the sticks at it, sync'ed them up, and she runs great. Also installed new Donlap 404s and new brake pads on the rear. Waiting on some after market petcocks and this puppy will be ready to run with the big dogs

[trbig]

Did you read on here of other people's suggestions that these bikes like a slightly rich mixture? They say just a tinge of the orange.... but if it's running well and you're happy, stick with what you have!

Tod

[wingnut]

I'd read that they liked to run a little richer than the cobalt color but that was in referance to the 1100 so I didn't think about it working on the 750. Same carb so it does make sence. Funny thing is after color tune and sync it now starts on no choke when temp is above 50 degrees and it pulls hard all the way to red line. Owner is real happy with it so I'm not inclined to mess with it. Triples sure do sound weird!