Topic: carb problems

[newkansan]

I am helping a buddy with his 77' cb750.  It had sat for a little too long.  We took the carbs off and cleaned them.  Now back on it seems like only the number 1 carb is getting fuel to the bowl.  Is the accelerator pump supposed to pump fuel into all the carbs.  If so is there an easy way to test the see if the pump is working correctly?


Thanks
Rodney

[scondon]

     The accelerator pump does not supply fuel to the bowls, it just adds a little squirt of gas into the carb throats. If you're only getting gas in one bowl then your problem lies elsewhere. How are you determining that there is no gas in the bowls?

[newkansan]

I unscrewed what I believe is a drain plug,  fuel came out #1 all the rest were dry.

[scondon]

Well, if the drains aren't plugged on the other 3 (which can happen) then I'd guess that either

A)  the hard fuel line at the back of carb bank is seriously gunked up

B) floats/ float needles are stuck or installed incorrectly

C) Drains are plugged, there is gas in the bowls

   Fuel is gravity fed from the tank into the bowls and there is nothing to stop it from doing so except the float needles or blocks in the line. Generally I've only had problems with bowls overflowing rather than not filling at all so your predicament is puzzling

[eldar]

You will probably want to pull the carbs apart. You will also want to do a very good cleaning of the low speed jet.
Pull your floats off and clean in those areas and replace the float valves. You can also get fuel tubing and replace the lines between the carbs.

[newkansan]

Thanks for the input. 

We did take it all apart and cleaned it real good. My buddy put them back together. So He may have put the valve in wrong.  He's not to mechanically inclined.  I showed him how to do the first one and then he did the rest.  So it makes sence that the first one work and the three  others dont. HAHAHA.

Looks like were gonna have to pull them off again to see if he botched it up.

Thanks again guys

Rodney

[newkansan]

Just one quick question to see if I have it right.

The fuel is distributed to the carbs through the rubber hoses that connect the carbs?

Just want to make sure I have the right area all cleaned out.

thanks

[jdpas29]

yes.... that is correct. 

if it's never been done, it might be a good idea to go ahead and replace the tubing inbetween all the carbs.  you can remove the bowls off of the three that are not filling and blow compressed air through the hole where the rubber hoses interconnect to make sure the metal portion of the connecting tubes is not obstructed as well...  just be mindful that compressed air against your floats could do damage so you may want to remove them.

check your float/float needle assembly to make sure it's not binding at the top. 

[hcritz]

Hey Newkansan...
It is possible to put the floats in upside down...they won't fill the bowls that way....
When I got my bike one carb wouldn't run...and that's what was wrong...
Quick and easy to check!