Main jet blues

Got to a dyno at Jordan's yesterday 'cos I needed to be reassured about mixture now I've swapped to an S&S from an SE air cleaner, standard CV carb..
Nightmare!
As soon as it went onto main jet the air/fuel showed as less than 18.. in fact damn near zero fuel. You'd have though it was blanked off. Only making about 40hp!

Chuggged home and got the carb off and checked jet (180) which I'd thought would be fine. No sign of blockage but blew it all through on the air line.

OK if there was a major air leak you'd expect some popping etc. Nothing.
Slight hesitation 2400-3000 but not much.
Was their gas reader just nuts?

Can't get onto a dyno for a while.

I'm not happy. Any advice before I bolt it all back on?

[robbiemac]

Hi, a good place to start would be S&S website, got all the info you need for checking out your carb. If it's a super E or G look for the tech sheet on that, it's just over 2MB on Adobe format. Also, on bikernet.com in the garage area there is a basics on S&S carb setup.

[robbiemac]

here's a link http://www.sscycle.com/iframes/instruction.php

here is another http://www.bikernet.com/garage/PageV...sp?PageID=1081

[Phil]

S & S Main jet sizes would be somewhere between .070 to .080.
Where would you have got a `180`?
Unless it is a Keihin jet, in which case throw it away! Too small...Wrong!
Try a .074 S & S jet as a starter.

[Folkie]

I think he means he swapped from an SE to an S&S air cleaner. Sounds like he's still got the CV carb on. Is that right Richard?

[Hawgste]

If its a dynojet cv you probly want 170/175 jet.
what size pilot jet?
what needle height.

hi guys
Yep CV with S&S AC.

Rode 40 miles back from dyno with no problems, though I kept throttled back.
No hesitation, no popping, no overheating. Easy starting hot and cold.

Checked the jets, needle, vacuum connections, slide and diaphragm. All jets blown through and the rest look good and smooth operation.
Some partcles in the float bowl and the float seems to be at the right level.

Pilot is 42 but I've no qualms about that. Always starts easily and ticks over cleanly.

When I took the needle out the three shims were stting in the slide. Can't be positive that they didn't slip off as I got the needle out.
Needle has no identification numbers but has six grooves. Circlip is in the third groove up.

All now back on the bike and no sign of any leaks. Starts as easily as ever and revs cleanly.

The only thing I ever wonderd about was the length of time I has to keep the enricher fully open (but thet was the case with the Ducati) and a tendancy to "hunt" on small throttle openings.

They pulled the run because of the low gas/air reading, though the pipe was well into the muffler (slotted in through the holes in the baffles).

Going out tomorrow so I'll report back.

[robbiemac]

Fingers crossed for ya.

Thanks Robbie
It all revives a nasty memory from the very dim and distant past when I knew things were wrong but just let it (BSA) rip, siezed the piston, tore it in two and bent all the valves. But that was when a whole bike cost £40.
s**t

[Folkie]

Originally Posted by richard1200

The only thing I ever wonderd about was … a tendancy to "hunt" on small throttle openings.

That could be that you're a bit lean on the idle mixture?