Topic: Surging idle

[rchrdms]

After rebuilding my carbs and replacing the floats and gaskets, I'm now having trouble with an erratic, surging idle. I have tried to adjust the idle mixture according to
the book, but it doesn't seem to help. It runs extremely rich, with black deposits shooting out the back. It starts quickly but runs worse as it warms up. The compression
doesn't seem to be the problem. The dealer says the the float needles and seats could be worn, but they looked OK to me. It has a good spark and timing is right on.

Any ideas. Thanks.

[rchrdms]

BTW, it's a '72 CL 350 twin. Didn't mean to leave that out.

[cookindaddy]

Did you pull the idle jets? For me I did not take them out, thinking that the carb cleaner soak and air blowout was enough. It wasn't. The passage in the idle jets is extremely tiny, very very tiny and three of my four were badly fouled, even after my careful job without taking them out. The idle was very uneven and the bike would surge and die all over the map. After I bit the bullet and took them out and cleaned, it is beautiful.

Mine is a 750 K8 and my advice may mean nothing with your 72 CL 350 twin, but if it helps you ...

[rchrdms]

Thanks for the reply. Yes, I pulled all the jets and the air needle screw too. I sprayed a lot of Gumout over everything. I did not tank it though. I am wondering if, by pulling the carbs apart so many times, I need new gaskets already. I may replace the float needles and seats as well.

[cookindaddy]

Were you able to see light thru the little tiny bore down the length of the idle jet? It is really tiny.

[rchrdms]

Do you mean the air inlet inside the idle jet passage? I didn't check. I did remove the actual brass jets and clean them with Gumout.
I sprayed up those inlets too. Maybe I'll have to tank this thing, then blow out the carb body with the air chuck at work.


Thanks again for answering.

[cookindaddy]

Three of my four were clogged and the idle was terrible. You really have to see light thru them before you know they are clean. As I said, the passage is really tiny, I didn't believe how small. Some here advocate poking a soft wire (like copper) through the passage to help knock the crud out. After I did that, the idle was perfect.

[rchrdms]

I did tank these carbs and it worked much better. I could see spray jet out from the hole in the main air passage(it was only gurgling out previously).
Now I'm having difficulty with the charging system. So that's next. Thanks for your help.