Author Topic: 78 750K #2 waaay rich  (Read 1989 times)

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eldar

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78 750K #2 waaay rich
« on: May 17, 2005, 11:42:06 am »
Well I dont get to work on my bike much since it is in storage a couple hours away but I got to this weekend.

I have had this issue for the last 2 years now. My number 2 cyl runs very rich.

I have checked timing and it looks good. I get spark and have replaced the plugs with standard d8ea
the spark looks good it is blue and looks decent.
I have tried to sync and I think the carbs are very close. I have adjusted my floats to 14.5mm which is spec for my bike, remember this is a 1978 750K.
New float needles and the carbs seem to be very clean, I do not get any thing but clear cleaner and the jets appear to be clean.

Now to give ideas. I can close the idle screws on 1,3,&4 and the bike wants to die. This should be normal. I close the screw on #2 and nothing changes. The accel pump is assembled correctly and is new. If I hold my hand over the carb air opening then move, I get gas that spits out.
This #2 darely gets warm when compared to the other cylinders and the muffler stays cold.
Now I did put new exhaust on and theyhave not been welded yet but ONLY #2 is running rich.
It has to do with the carbs I am certain, but I am not sure what I should try next.

Offline Jonesy

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Re: 78 750K #2 waaay rich
« Reply #1 on: May 17, 2005, 01:39:49 pm »
Did you check the dimensions of the idle jet? When I bought my bike I had the same issue and it was so bad that it would drip gasoline from the exhaust joint on the cylinder head. I cleaned the carbs and installed new float needles, figuring one was overflowing. I put it back together and it kept doing it. It turned out someone drilled out he #2 carb idle jet to about the size of a 140! After installing a complete carb kit with new idle jets, it hummed on all four. Not sure if you are having the same problem but it's something to look at. I had my carbs apart 3 times before I noticed!
"Every time I start thinking the world is all bad, then I start seeing people out there having a good time on motorcycles; it makes me take another look." -Steve McQueen

eldar

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Re: 78 750K #2 waaay rich
« Reply #2 on: May 17, 2005, 02:01:24 pm »
Well all I can say is that I have never drilled the jets and the bike ran fine before it got hailed on then I had to put it in storage cause i moved. So the jets have not been drilled. Unfortuneatly I have pressed in jets so I doubt i can replace them. I am thinking it is something with the float but until this weekend I have never had gas overflow. I did get a couple of drops this time which has never happened before. I may need to clean the float seat.

ANy other ideas?

057 adnoh

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Re: 78 750K #2 waaay rich
« Reply #3 on: May 17, 2005, 02:20:22 pm »
This may sound strange but take apart the air filter and make sure you dont have a mouse nest in your intake track or air box . my buddy had just that in a 79 cbx drove him nuts and really upset the mouse!!!

eldar

  • Guest
Re: 78 750K #2 waaay rich
« Reply #4 on: May 17, 2005, 03:32:48 pm »
Nope this happens even with the airbox off!

057 adnoh

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Re: 78 750K #2 waaay rich
« Reply #5 on: May 17, 2005, 06:54:44 pm »
maybe the over flow tube in #2 float bowl is plugged and you are getting flooding into the engine :-\

057 adnoh

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Re: 78 750K #2 waaay rich
« Reply #6 on: May 17, 2005, 07:01:04 pm »
you said the pipe stays cold have you tried replacing the plug cap on #2 . try switching wire 2 and 3  ignition wires and see if the problem moves to # 3 :'(

eldar

  • Guest
Re: 78 750K #2 waaay rich
« Reply #7 on: May 17, 2005, 07:56:30 pm »
well I have tested the cap and it is in the same ohm range as the others but I have not tried switching yet. I never thought of that but since both plugs fire at the same time no matter what, I see what you are getting at. The pipe does warm a bit but nothing like the other 3 do. So it does fire sometimes.