Sooty plugs 0n my 75( Need float Height also)

classic Classic list List threaded Threaded
5 messages Options
Reply | Threaded
Open this post in threaded view
|

Sooty plugs 0n my 75( Need float Height also)

katman
Hi guys, As yoou know I finished my 75 project. Runs good but My plugs are sooty
when I come back and check. Haven't gone on a real extended ride yet. Had 2 carbs leaking out
of the overflow so I took them off to check the seat again. Carbs were rebuilt by the guy who done my 77.
I want to recheck the float height. What is the height if the carbs are upside down. It's easier for me
than trying to hold them at an angle. My 77 is .570 from lip. This is a 75K. Mains are 105( which seems small
when manual says 115-120) Pilot are 40's. Carb boot seem stiff so I don't know wheather I am getiing
any leakage there. Any idea's on why my plugs are sooty. New points-timed and valves adjusted.
Thanks
Reply | Threaded
Open this post in threaded view
|

Re: Sooty plugs 0n my 75( Need float Height also)

shinyribs
Administrator
Overflowing carbs are enough to cause sooty plugs. For stock airbox and pipes the 105 main is probably OK. Will it rev to max rpm OK? If it will then your jets are big enough. The 40 pilot is a tad big,though.

On float height I just set mine to level. Make the flat hinge part of your float parallel to the bowl gasket area. Not the bendable tab used for adjusting float height,just the flat part.Works for me at least.
Reply | Threaded
Open this post in threaded view
|

Re: Sooty plugs 0n my 75( Need float Height also)

katman
Thanks Shiny, Any recommendation on what I could drop the pilots too.
Reply | Threaded
Open this post in threaded view
|

Re: Sooty plugs 0n my 75( Need float Height also)

shinyribs
Administrator
I believe 35 is stock. I'm not sure on that, but it should be in the FSM. There were a few different tunes for different models. It takes some sorting to get it figured out when you are in the FSM. But the pilot is not in play a whole lot. It is just a transistion circuit between the idle mixture and the mains. If you ride highways a lot you'll use that circuit very little. If you ride in town or traffic then you will be using them much more.
Reply | Threaded
Open this post in threaded view
|

Re: Sooty plugs 0n my 75( Need float Height also)

katman
Okay Shiny and anyone else that wants to jump in. I took the carbs back off and checked the needles.
Clip was second from bottom. I moved them to the center and put it back together. Fired it up and sounded alittle off. Went up the street and bogged under accel. came back and found out #3 wasn't firing.
No fuel in bowl. I think the float in bowl on that carb was hanging up. After poping bowl several times and checking, finall got fuel. Rode it and still some hestitation under fast accel. Should I put the needles back were they were. Also getting some backfire in pipes at idle. And I swear they chirp at the rear. The are 341's and I don't know if I can get used that sound. Anyone had experience with these pipes. Adjusted the floats like you said Shiny(Float metal frame even with bowl when upside down. No overflow)