Carb; In or out?

James A. Corbally /

Can anyone tell me if carb adjustments are in for lean, out for rich, or vice versa? My owners manual doesn't say, and I'm seeing conflicting reports on the net.



Re: Carb; In or out?

Generally out for richer,in for leaner.BYE!

Re: Carb; In or out?

Or, if we're talking main needle jets, raise the circlip up a notch to lean, lower to richen.

Re: Carb; In or out?

Depends entirely on the carb... some are one way... others the opposite.

Generally :

If your adjustment screw is 'upstream' of the carb slide... then IN is richer.

If the screw is 'downstream' of the carb slide... then OUT is richer.

BUT... those adjustments are for the idle mixture only.. they have no effect on anything faster than half throttle.

Click on 'resources' above... then 'articles'... then find "How to fix your Moped"

there is some info there on carbs.

Brian... Are you from MI too?

since I read that thing about you walking out 15 miles from the MI woods ...(uphill the whole way of course)

Re: Carb; In or out? - Help!

James A. Corbally /

Thanks everyone for your input.

I should probably have mentioned the type of bike. It's a Suzuki Katana AY50, and I know nothing about the carb beyond the fact that I can find no information about it on the net.

Has anyone ever fiddled with this carb-type before?

I don't know how to tell if the jets are down or upstream. I don't even know what a circlip is!

I'm suspecting it's running rich, as I have my doubts about my fuel economy, and the old sparkplug I took out a while back has a black, encrusted outer ring, a brown coloured "base" on which sits a black "disk" in the centre, with a brown coloured "arm" reaching across above it.

Any ideas? When motoring, I tend to build up speed ( a little slowly I feel), then get to half throttle and must let off the throttle a little in order to reach top speed. Once I do that it accelerates "moderately" to full speed. Otherwise it will chutter a littel and gain no speed, even slow a little.

However, if I do push it past half and near full, I can sometimes get it to pulse forward, then pull back, and sometimes it'll even "burst" up to full speed, faster than it would using the method described above.

Any help would be appreciated. I can only take it apart at the weekends, as it is my work transport. I'm also concerned about spilling fuel/oil everywhere if I were to take it off.

Any help would be appreciated.



Re: Carb; In or out? - Help!

Now that sounds a lot like a clogged exhaust port or muffler! Could be an intake air leak though.Always replace the spark plug right off the bat.They just don't cost that much.But I'll guess it's a carbonned up exhaust.BYE!

Re: Carb; In or out? - Help!

James A. Corbally /

Thanks for your input don. The bike has near 10K on it (it's about 10 months old), and has been doing this ever since my carb "froze" back in November '00. I was losing power, kept getting slower and slower until it sounded like a machine gun when the throttle was opened, but no power. I only had this happen on one day, and I drove it in to the dealer that afternoon. I had been noticing a "flat spot" ever since getting it back on the road, but it seemed unrelated.

They thought it might be the airfilter, the cover of which had been stolen and replaced by me, but it it turned out the intense cold we were having had caused the problem, and they fitted a carb heater which got it running again.

Since that day however, I've had to throttle as I've described previously in order to get top speed.



Re: Yup

Actually, it was a pleasant somewhat cool september day. I ran out of gas on a M.C.C.C.T. trail, the Hunt Creek loop to be exact. That was how far I walked to find another human, some guy in a beat up Subaru Brat, who gave me some premix and a ride back to the bike.

Re: Carb; In or out? - Help!

James,you say your carb. `froze'.Did you mean frosted up at the intake venturi? Or water in the float bowl?This sounds like a racing bike to me and that's Fred's field.I would only guess you're running too rich and that heater mod may be causing air restriction,but I don't know racing bikes.

Re: Carb; In or out? - Help!

James Corbally /

Well, that was their word. Not sure what was the nature of this freezing, they didn't explain it (I probably wouldn't have understood anyways, and they're not exactly customer friendly)

It's a street bike, all parts stock currently. I'm beginning to think it's running rich, but I won't fiddle with the carb yet.

I'm hopefully getting the service manual tomorrow, so I should be able to figure out how to lean it. I may even remove the carb and check it over the weekend.



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