Carb flooding #2

If it's broken or just needs tweaked

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CanCB650
Posts: 32
Joined: Thu Jan 02, 2014 12:31 am
Location: Toronto, ON, Canada

Carb flooding #2

Postby CanCB650 » Mon Jul 31, 2017 9:20 am

Hey,

I don't have much experience with carb boot problems, but I think I may be experiencing some... I'll do my best to explain the issue, so please bare with me.

The jetting is stock on my bike. I had no choice but to put pod filters on the bike as the original airbox did not come with the bike. I've noticed the bike has been running way too rich with the choke fully open over the last few hundred km. I've spoken to a few guys at my local shops and they thought there could be some cracks in the carb boots resulting in not enough air being pulled through the pod filters. Additionally, I have noticed there is fluid dripping off the bottom of carb #2 onto the engine case (yellowish tinge and sticky - i'm guessing fuel varnish?).

Any tests you me able to suggest that may help diagnose the problem would be greatly appreciated.

Thanks in advance!

flatlander80
Posts: 12
Joined: Fri May 05, 2017 9:08 pm

Re: Carb flooding #2

Postby flatlander80 » Mon Jul 31, 2017 11:57 am

I'm no expert on carbs and jetting, but here's what I know from a little experience and what others have written on various forums.

If you have a cracked carb boot, you'd be running lean, not rich. Basically a crack there makes it way to easy to suck air in vs. fuel, and you'd be lean. If you're running the stock jets with pod filters, you'd also likely be lean in that case as well, since pods have less resistance than the stock air box. I don't know what you're observing that tells you you're running rich or flooding, so maybe you'll have to give us your reasons/observations there.

If you're getting fuel varnish coming out of an overflow, you need to take your carbs off, clean them, and set the float heights. The clear tube method is the best thing you can do for that. Look that up on the SOHC/4 forum.


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CanCB650
Posts: 32
Joined: Thu Jan 02, 2014 12:31 am
Location: Toronto, ON, Canada

Re: Carb flooding #2

Postby CanCB650 » Mon Jul 31, 2017 1:31 pm

flatlander80 wrote:I'm no expert on carbs and jetting, but here's what I know from a little experience and what others have written on various forums.

If you have a cracked carb boot, you'd be running lean, not rich. Basically a crack there makes it way to easy to suck air in vs. fuel, and you'd be lean. If you're running the stock jets with pod filters, you'd also likely be lean in that case as well, since pods have less resistance than the stock air box. I don't know what you're observing that tells you you're running rich or flooding, so maybe you'll have to give us your reasons/observations there.

If you're getting fuel varnish coming out of an overflow, you need to take your carbs off, clean them, and set the float heights. The clear tube method is the best thing you can do for that. Look that up on the SOHC/4 forum.


Thank you very much for the response! The rich observation came from fouled spark plugs and the flooding was from the fuel varnish dripping off the bottom of carb #2 (where the fuel accelerator diaphragm is). It didn't appear to be coming out of the overflow tube.

Also, I should say its a 1979 model.

flatlander80
Posts: 12
Joined: Fri May 05, 2017 9:08 pm

Re: Carb flooding #2

Postby flatlander80 » Mon Jul 31, 2017 1:49 pm

I still wouldn't say it's flooding. Fouled spark plugs could be a few different things (oil from rings or valve seals, for example), but I'd still bet money you're probably running lean. These bikes run lean at the best of times...

If I were you I'd definitely get the carbs off and go through them. Check the accelerator pump (there's a diaphragm in there that could be shot, and a few o-rings). Again, if the fuel coming out is yellow and varnish-like, they need cleaning. I believe the 79 carbs are the mechanical slide type (same as mine on the 80). Remove all your jets (including the pressed in ones) and clean thoroughly. There are emulsion tubes that get gummed up, and those may need a wire passed through them to clear up.

Good luck!!


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