Carb issues

R3DS!X

R3DS!X

Whatever that means
So my DR350 I picked up initially wasn't running, it would start and run but only with choke. Pilot jet turned out to be occluded, so rebuilt the carb.

now she starts with choke and after a few seconds idles fine, starts and accelerates fine, BUT intermittently when I try to maintain speed she sputters and stalls like she is running out of gas. pretty odd. I speak carburetor conversationally but I'm not fluent. I looked around to make sure there weren't any hoses disconnected or something not seated but AFAIK everything is proper.

Could it just be the AF screw? I set it to 2 turns out as was recommended by the innerwebs. I hope I don't have to fiddle with that cause it's in a bitch of a spot and I have to pull the carb to get to it basically.

Could it be bad gas or too high of an octane? i used 91 in it but maybe a lower octane would run better?


FANKS
 
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DucatiHoney

DucatiHoney

Administrator
Staff member
Moved to garage.

I've tried exactly once to deal with carbs. I don't do that anymore. G'luck!
 
wilit

wilit

Well-known member
Not a fuel octane issue, most likely a carb issue.

The AF screw is only for idle. Once you crack the throttle, it's all about the needle and main jet.

How's the float level and float needle and seat? Also, how's the slide diaphragm? No tears and it's seated properly in the groove at the top of the carb?
 
auntiebling

auntiebling

megalomaniacal troglodyte
Staff member
R3DS!X said:
yup. sprayed carb cleaner and compressed air through all kinds of passages.
Click to expand...

that isn't necessarily enough.

find little wires to stick through everything you can

also, single cylinder bike if it ain't running right you're chasing your tail untill you confirm the valves are adjusted properly and ignition timing is correct
 
R3DS!X

R3DS!X

Whatever that means
I guess it wouldn't hurt to do the valves. I don't think I have the tools to check timing though.

Bike has only 2k miles on it
 
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R3DS!X

R3DS!X

Whatever that means
wilit said:
How's the float level and float needle and seat? Also, how's the slide diaphragm? No tears and it's seated properly in the groove at the top of the carb?
Click to expand...

Float level looke3d fine, diaphragm was in tact and seated proper. Float needle was replaced in the rebuild and in the same position.
 
Rob

Rob

House Cat
auntiebling said:
that isn't necessarily enough.

find little wires to stick through everything you can

also, single cylinder bike if it ain't running right you're chasing your tail untill you confirm the valves are adjusted properly and ignition timing is correct
Click to expand...

Guitar strings... get to work.

Chemicals and air won't knock off the glazed old gas that's coating your passages.... I thought what you thought and did what you did... then did what we're telling you and it ran just fine.

Edit: I think what we thought is good for maintenance... but not for raising the dead.
 
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Lucytriple

Lucytriple

Wrrrench
Really sounds carby to me, but after you check the valves maybe think about the float level again. Too high can really bog that thing down, and changing the float needle requires a level check. Interesting that it's intermittent and only at steady throttle, though. I'm rambling and thinking while typing but weird things happen. Sometimes vent hoses catch the air in just the wrong way, assuming this steady throttle thing happening while riding. My last thought is if you replaced only the float valve and not its seat, your level might be creeping higher because it's letting a bit more in. Conversely, maybe that float level is too low? Can you get a tube on the drain of the bowl and see how high the gas flows?

ps they sell nifty extended mixture screws for hard to each situations and you get that thing warmed up and try turning 1/4 in, listen for change, try turning 1/4 out and listen for change. I like leaving it at the highest idle.
 
R3DS!X

R3DS!X

Whatever that means
Lucytriple said:
Interesting that it's intermittent and only at steady throttle
Click to expand...
This is the part that's got me fucked up, If it was bogging when i whack the throttle open or at idle it would be easier but bogging intermittently when holding throttle steady sometimes is kinda odd.
 
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edzx6

edzx6

Well-known member
Out of the 14 bikes SVJ and I are working on at any given time only 2 have fuel injection.

I can tell you right now that either one of the small ports in the carb is clogged still or something very tiny got loose after your rebuild and lodged itself somewhere new. The only thing to do is take them off again and clean again. You may do this 2 or 3 more times.
 
edzx6

edzx6

Well-known member
I am so sorry, I wish I had better news. I know it is a pain in the ass, that is why I make my son do it now :)
 
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