Author Topic: Roadrocket 1955 ( not super) has sooty exhausts  (Read 187 times)

Offline barry2

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Hi mates
my R/R has sooty exhausts , The carby is a 376/286  Amal mono' 1 1/16"  the pilot was right but the main jet was 250, should be I think 240, would that  cause it to be that rich, the needle was at No2 groove so dropped it to leanest just to see what happens, any thoughts?
Barry
WA

Online morris

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Re: Roadrocket 1955 ( not super) has sooty exhausts
« Reply #1 on: 31.01. 2019 20:09 »
Exhausts will always be sooty on a carb fed bike. The colour of the plugs will tell you more about what’s happening in the combustion chambers. A colourtune may also be a wise investment for setting up your carb
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Online muskrat

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Re: Roadrocket 1955 ( not super) has sooty exhausts
« Reply #2 on: 31.01. 2019 20:33 »
G'day Barry.
Dropping the needle (raising the clip) should help but the needle jet and needle wear. it would only take half a thou" to give the same result as the next size up jet. I'd replace both.
As morris said plug colour is the best way to tune with plug chops. I have a spare Colour Tune you could borrow. Their good for getting pilot and slide right. Plug chops for needle and main.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
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Offline barry2

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Re: Roadrocket 1955 ( not super) has sooty exhausts
« Reply #3 on: 01.02. 2019 06:54 »
Hi Mates
My ex' pipes are thick w/ soot after I cleaned them after about a week
Thanks for the help and offer, but I'm in WA, I have a colour tune hven't used it for years , will dig it out , I think maybe the fuel level is too high, when I took the pilot jet cap off  petrol took ages to stop flowing ( after a very hot day and night, will let you know how I get on
Barry
WA

Online muskrat

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Re: Roadrocket 1955 ( not super) has sooty exhausts
« Reply #4 on: 01.02. 2019 13:22 »
G'day Barry.
Put a piece of clear tube (fish tank air line) over the pilot and bring it up p[ast the float bowl. Turn fuel tap on and see where the fuel level is. Should be a pip in the middle of the bowl cover.
Cheers
'51 A7 plunger, '57 A7SS now A10CR, '76 XT500, '77 AG175 '83 CB1100F, '81 CB900F project.
Australia
Muskys Plunger A7

Online Triton Thrasher

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Re: Roadrocket 1955 ( not super) has sooty exhausts
« Reply #5 on: 01.02. 2019 19:23 »
Lowering the needle to compensate for a worn needle jet will make the mixture weak at typical highway speed throttle openings.  That can be dangerous to your engine.

Get a new needle jet.