Carb. Inspection / Cleaning

[tsal]

1979 R65
Heres the scoop. Start the bike up cold, and it will run only on right cylinder. After a about 60 seconds running, the left cylinder will kick in, and the bike seems to run fine after that. Getting good spark both sides. If I squirt some gas in the spark plug hole left side before starting, she will fire right up on both cylinders. So I am assuming it is a fuel problem.
I dropped the float bowl and checked the float, which seems to be working ok. The left carb is now off, and on the bench. Have any ideas what I should be looking for?
Thanks,
Tony

[Bengt_Phorqs]

Tsal, if you just went thru a clean and rebuild I would double check the "choke" on that side.  It may be that the cable is not adjusted quite right or perhaps it was reinstalled backwards.  The plates inside are "handed" and can be sensitive.  I've had that problem myself that is what I found.  Of course it could also be the butterfly plates or the idle mixture screw.  Try one thing at a time to isolate the problem.

[Bob_Roller]

Maybe a good cleaning, spraying carb cleaner through the drilled passageways, jets and such .

There's a paper gasket under the 'choke' assembly, check condition .

Also there are 4 or 5 small holes in the brass disc that is inside the 'choke' cover, make sure these are clear as well .

[donbmw]

The jet in the bowl for the choke could be stopped up. I had this on my R90 when I first bought it but didnot know this until cold weather came.

Don

[tsal]

I have only had the bike about a month now, and the problem has been since day one. I do not have any service history information on the bike so I don't know if the carbs were messed with before I got it.

[montmil]

Simple fix. My '81 did exactly the same thing. Drop the float bowl on the afflicted carb and use a needle or a very small numbered drill bit to open up the fuel passage at the bottom of the enrichener circuit fuel "well". It'll fix your start issue and won't cost you a red cent.     Monte

[tsal]

Thanks Monte,
Took it all apart, and blew out all jets and passage ways i could find with the air compressor. If i get time during the week, i'll throw the carb back on and see if that fixed it. Thanks everybody for your help

one last thing, there is a hole in the slide, that I "think" was facing the back (air box side) but cant remember for sure. I had the diaphragm off, so i couldn't use the tab on it as a guide. does it matter which way it gos in?

[Rob Valdez 79 R65]

Feel free to re-size your photos to make it easier to view.
This is 400 x 300 pixels:

[Bengt_Phorqs]

It appears you have not removed the diaphragm from the slide.  If that's the case then the small tab on the diaphragm will fit into a corresponding indention in the carb body.  
It does matter, but since I can't remember which way just now that should get it back together.  No doubt one of the more experienced mavens can chime in.

[Bob_Roller]

There's a small indentation in either the carb body, or carb top, where the tab is supposed to reside .

[Barry]

one last thing, there is a hole in the slide, that I "think" was facing the back (air box side) but cant remember for sure. I had the diaphragm off, so i couldn't use the tab on it as a guide. does it matter which way it gos in?  

Tony

The way I read your question - you are unsure if you put the diaphragm back on the slide 180 Deg out so that although the diaphragm tab would fit in the carb body indentation the slide could be back to front.

If that is the question the answer is the vent hole in the bottom of the slide faces towards the engine. I've never had my diaphragm off so I'm having to assume mine are correct.  I don't know for sure if it even matters.

Just checked around to be sure I was correct and as ever the 'Bum'
has every bit of detail covered. The hole does face towards the engine.

[Flash]

There are two locating tabs on the diaphragm. There's one on the inside that locates it properly onto the slide, and a tab on the outside (which you can see in your photo) which locates the whole assembly to the carb body. If you didn't see the inner one when you installed the diaphragm, you should take it off and reinstall it.

[Rob Valdez 79 R65]

Flash got it!  BINGO!

[montmil]

Thanks Monte,
Took it all apart, and blew out all jets and passage ways i could find with the air compressor...

I doubt air alone will clean out the bonded sediment that is clogging the fuel passage between the main float bowl and the enrichment fuel well. Poke it.    Monte

[Rob Valdez 79 R65]

I doubt air alone will clean out the bonded sediment that is clogging the fuel passage between the main float bowl and the enrichment fuel well. Poke it.    Monte

That particular passageway is probably safe from overindulgence with a poker, but on any of the others in the carb body, you want to use a soft wire, like a single strand of copper from a lamp cord.  You don't want to scratch them.