Help Please... Tuning stuff

Right, since the Goose has been running rough[1], presumably due to it
running rich, I thought I'd try and put everything back to standard (plus I
need the road can back on ready to Mot the bike next month). The guy who I
got the bike off gave me a plastic bag, which contained a few screws from
God knows where, and what he claims to be the origional main jet.

Today, I stripped the carbs, changed the main jet, checked everything else
was clear, then rebuilt the carbs, and refitted the origional exhaust. Still
running rough. Opened the carbs again and changed the needle valve thing to
the only other setting available, put top back on. Put fuel tank back on,
turn to on... carbs flood :-/

Stripped the carbs again, put new o-ring things on parts of the floats and
build up again, carbs don't flood anymore, but it's still running rough.
The only other thing I can think to do is play with the mixture screw or try
a new spark plug. Any advice anyone?

[1] Rough as in if you open the throttle, it nearly chokes it's self then
picks up after about a second, but pops and backfires constantly.

 

next time you buy a 2nd hand bike, make sure it's running properly
before you part with the cash.

 

Check for air leaks at the carb inlet manifold/rubber and exhaust header.

--
Petel .
02 M2 Buell.
C90-ZZR.

http://homepage.ntlworld.com/peteh1/website/index.html

 

Well, it did appear to be running ok with the race can on, and it's just
slowly started getting rougher. Then I found out it was supposed to pick up
between 7-11 thousand Rpm, which it doesn't, but that could of been due to
the attempt whoever made at tuning it for the exhaust.

 

The carb inlet manifold/rubber is fine, but I'll have to check the exhaust
header.

 

Fuel is fresh, so head down to local bike shop later for a couple of spare
plugs.

 

[1] Rough as in if you open the throttle, it nearly chokes it's self

seek professional advice...balance carbs...look at ignition timing
umm...chokes can be either rich or lean, rich usually recovers and revs
lean will recover for a bit and struggle to rev...although it can be lean in
the idle and rich in the main frinstance, then it will recover, run ok, then
die in upper revs

pops and backfires is usually ignition or cam timing
lean idle will pop and crackle on overrun
on 2 strokes carbon build up can be a problem

 

Do me a favour;-)

Post make/year/model of bike (not just "Goose")
Post carb make (Keihin/Mikuni/Stomberg!) and diameter and type (normally
cast into the carb body somewhere I.E PD-375D.
CV or round-slide?
Tell me what size main you changed to.
How many turns out on the mixture.
Std or aftermarket filter.
Make of exhaust.
Type/heat range of plugs (hotter or colder than Std.)

I might be able to help, then again I might not.

--
Petel .( asking for a full diagnosis by description and text on the internet
is like asking directions from a thermos-flask.....full of
well-meaning,warming content...no fucking information!)
02 M2 Buell.
C90-ZZR.

http://homepage.ntlworld.com/peteh1/website/index.html

 

What, a 350 four-stroke single?

Like hell.

 

You can't balance the carbs on a single, you terminal twonk.

 

Didn't Yamaha put twin carbs on the XT600 and SRX600 singles, and
Honda used the same idea on the 84-84 XR350R single?

To be fair, I don't think you balance them so much as need to adjust
them somehow, since they aren't identical.

 

Just looked on the clock, and 11 thousand is into the red zone, so you may
be right.

 

Probably told him this in the hope that he'd actually try it!
"sorry mate, but you blew it up by thrashing it. No refund for you meboy"
Or maybe the term "pick up" is another word for disintegrate?
JB

 

"The bike starts to pick up its pace from about 7000rpm onwards to the red
line (11,000rpm), but if you want to reach maximum velocity it's necessary
to change gear as late as possible to carry as many revs through to the next
gear."

From http://www.xenaverse.free-online.co.uk/goose/index1.htm

In the opinions section for the engine.

 

That's right. The CV car opens first, at low throttle openings, and then
the slide at full chat. Or is it the other way about?

But "balancing" carbs means synchroising carbs, one per cylinder, so
they open together. Not the same thing at all. In fact, quite the
opposite.

 

Where he comes from, it's a term for a highly desirable sexy vehicle.

 

The Older Gentleman wrote

Highly sexy eh? I hadn't really thought of Snowflake like that but now
you mention it....

 

Suzuki SG350 1992 moecel (Blue, if that makes a difference

Mikuni, couldn't see anything other than "Mikuni" and "made in Japan" on the
outside, but it has the plastic top with the rubber bit in... That I can't
remember the name of right now.

CV I think.

Don't know since the number has come off, but from what the previous owner
said, it's the origional.

2 an 3/4

The origional suzuki one, which has some wierd expansion cahmber on it for
some reason.

Lets hope, I can probably find out some of the stuff in more detail like
taking the carb out to find a model number, and the plug type etc.

TIA