Accelerator nozzle cleaning - how?

[Tommy]

Tried to free the clogged accelerator nozzles today with carb cleaner and compressed air. No success. Can I remove the carb's top section while the carb is still on the bike?


Thanks, Thomas

[AdvRich]

Hi Thomas,

Yes. It's one of the nice features of the carbs. Those nozzles are press fitted and come out with a twist. I use a small pair of locking pliers with some protection on the tips. There is a screen inside of them, but a good soaking, blow out and finish squirt of brake cleaner should get them going well. The Yammer shop manual will help with the alignment for proper squirt location down the venturi. A magnet on a stick is good to have on hand if something happens to fall in and sit on the butterfly valve.

Rich

[Tommy]

Thanks Rich. It was easier to take it of than I thought. Was a bit tricky to turn the carbs the right way and pull them out at the left side. I will try to pull the nozzles later tonight. I have some red colored gas in the bowls. Thinking I might have to clean the entire carb.

[Lucky]

There is a brass weight & ball check under the nozzle. don't lose them...
you can clean out the nozzle with the wire from a needle threader.

also, there is a check ball & spring that you can slightly see when you take the pump diaphram off the side of the carb.  if that's gummed up, use a sewing straight pin in the hole to loosen it up & gummout with the straw tube sprayed in the check hole.

--Lucky

[AdvRich]

The Yamaha shop manual has a good set of diagrams to show the passages, what is inside them, and the air and fuel flow direction. Be careful as Lucky says with the check ball and spring now that you have the carbs off and can rotate them over. That red fuel is most likely floating bits of iron oxide from the tank. When the float bowls dry, you may see a bit of sediment collection of the same color on the walls. If so, you can bet it is in all passages, jets, etc throughout the carb to varying degrees of thickness and perhaps mixed with varnish from oxidized fuel. Has the tank been POR-15 treated?

Also, you have a master tech helping you with Lucky and a lot more good techs on here, so I'll give a little pressure on the footpeg and bars to pull aside for now. Cheers, Rich

[Tommy]

I appreciate all the fast responses I'm getting. I pulled out the nozzles, of course not without damaging one of the nozzle's soldered connection. Thanks to my second hobby (tube amps) the soldering iron was heated up quickly, and the connection was resoldered.

Turns out the nozzle itself was clogged, and the needle threader tip worked great! All free now. I had checked the acc pump before I took apart the carb, and it seemed to be working just fine.

I'm still debating if I should use this occasion to dip the carb. It seemed to be fine before I took it apart, except for the acc nozzle.

Thomas

[fret not]

You can guess whether it will run well or you can make sure.  If it doesn't run right you will be going back in there again.  It's your time and your bike. 

[QBS]

Whenever you are working in or around open carb throats ALWAYS stuff a rag or wad of paper down the venturis.  Otherwise, just imagine how your heart will stop when you see or hear something disappear down into the intake track. Absolutely do not depend on the closed butterfly to save your ass.  Save your own ass on the front end instead of kicking it on the back end.

[Tommy]

Thanks again for all the help. Did the throat stuffing - remembered that from working on cars with my dad. Well, I put everything back together, and she started right up. Went for a test ride, no stumble, smooth accel all the way up to 10k. I really like that bike.

[Tiger]

...I have some red colored gas in the bowls.

Well, I put everything back together...

...and you DID include an in-line gas filter (between the petcock & fuel pump), didn't you ;)

                              8) .......TIGER....... 8)

[AdvRich]

Glad to hear you got it sorted and it is running so well Thomas. Lot of fun this little scoot is...

Better than a rag for stuffing carb throats is a new nitrile glove – clean and not much sticks it to be transferred in. There's little room in the throat of these Mikunis for stuffing while performing a carb top off only job on the nozzle. Best is to pull the carbs as you did. I then put the open end of he nitrile glove over the intake boots and stuff the finger parts inside, and if long term secure them with a zip tie. Rich

[Tommy]

...and you DID include an in-line gas filter (between the petcock & fuel pump), didn't you ;)

YES!

[Tiger]

...and you DID include an in-line gas filter (between the petcock & fuel pump), didn't you ;)

YES!

:) SUPERB....... 8) Now go ride some more buddy  ;D

                 8) .......TIGER....... 8)

[jasonm.]

FYI, the rubber hose that connects the accel pump from rear to front often decays. And bits of rubber can clog the nozzle. Do NOT use rubber hose when replacing said hose. The orignal stuff was quiite good quality. But nothing today of rubber is as good. Especially w/ethanol fuels. I found Oregon chainsaw fuel line hose 1/8" fits and does NOT decay. It may get a bit stiff over time. But it's far better than rubber choices. Available at good lawnmower shops. It has a greenish tint to it.

[Tommy]

Thanks for the tip, Jason. I ended up getting a 3mm fuel line from a lawn mower shop after I was unable to find 1/8 at the local autostores. Guess I lucked out :)

[Brian Moffet]

I found Oregon chainsaw fuel line hose 1/8" fits and does NOT decay. It may get a bit stiff over time. But it's far better than rubber choices. Available at good lawnmower shops. It has a greenish tint to it.

This is what I use as well.  It seems to hold up fairly well and is easy to work with.

Brian

[raub]

Threadjacking:

Has the tank been POR-15 treated?

Is it a bad idea?

[QBS]

Probably not.

[raub]

Also, how much pressure is required to force fuel/carb cleaner through these jets?

[Tommy]

take out and clean with a small wire