At square one again after carb rebuild

alexmac

Been Around the Block
Today was restart date for my bike(72 CL350):

Work done:

1) Carbs disassembled, thoroughly cleaned all brass replaced (everything), new floats,new gaskets,float levels set with micrometer to manual specs
2) New OEM airfilters all boots done tight. No signs of wear in any of the rubber parts.
3) Carbs synched with throttle so they pull at EXACTLY the same time.
4) New fuel lines 1/4" snuggly done up with metal hose clamps. No leaks,no kinks, no fuel filters.
5) New plugs OEM NGK properly gapped. New plug boots. Plug wire trimmed back 1/4" to ensure good connection.
6) Valves set to factory specs
7) Timing set/ Points properly gapped as per manual.

Today I restarted it adjusted the idle screws to get it idling at approx 1300-1500 rpm.... after the choke was turned off. I put
my hand behind the exhaust to try to ensure that the pressure out of both pipes was the same. It seemed really hard to tell
which pressure was more because they seemed mostly the same.
Seemed to be running smoothly like a champ. I left the mixture airscrews alone at the stock 1 + 1/8 turn out from full close
as per manual for CL350 722A carbs.

Went for a ride approximately 10 miles.... on a forest road with no lights. At the light when I passed that area, The idle had jumped up to 3,000
I rode for a bit more and then pulled over to lower the idle with the screws. It seemed to work ok at 1500rpm... but if I tried any lower it would drop
below 1000 and die.
The manual says to set the idle with the screws to 1000-1200rpm and then on each carb turn the mixture screws until the engine reaches maximum speed
on both carbs and then reset the idle screws back to 1200rpm.
I tried turning the mixture screws and it didn't seem to change anything with the engine speed... so I turned them back to 1+1/8 out on both sides got the
bike idling again at 1500rpm and rode for another 7 miles into the city.

In the city, the rpm was at 3000 again when idling for the lights. I stopped had dinner for a couple hours and rode back home.
When the bike was restarted after dinner, the engine was warm enough that I started it without choke. It seemed to idle ok at 1500rpm.
Halfway through the ride home it was up to 3000 at the lights. I pulled over and readjusted the screws for 1500 rpm and rode off. At the
end of the forest road, at the light it would idle for 5 seconds at 2000, then drop to 1500 for 5 sec... then drop to 1000 then it would die.
I decided to keep it idling a bit higher by holding open the throttle a bit at the lights.

I got it home and it died in the garage from low idle.

The carbs are soo clean you could eat out of them. I don't get it.

When it idles. It feels great... no roughness whatsoever. The bike pulls like a champ at speed. It feels great.
 
I pulled the plugs today. The darker one is from the left cylinder

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I decided to try setting the idle again. I noticed that the left cylinder wasn't giving as much pressure as the right. It was also intermittant so I pulled
off the plug wire and trimmed it down another 1/4" and replaced it. It seemed to fix the intermittant problem. I am concerned because I am running
out of plug wire from the coils. I might need to get new coils and wires soon.

So anyways, I had read somewhere that you can set the idle by running the bike on one cylinder and setting the idle for each one. I tried that and I don't know
if I did it right. I would set one cylinder and then reattach the plug wire to the other and the idle would jump to 3k. I would then turn down the
idle screw on the cylinder I had pulled the cap on until I got proper idle. I would repeat for the other cylinder.

I didn't have too much time today to work on it. I have it idling at 1000 but I didn't have time to take it for a ride and see how or if the idle will hold there.

The left spark plug looked a bit dark like the cylinder was rich... but it could be from the plug not firing regularly due to the wire problem that I just fixed.
I turned out the mixture screw an extra 1/4 turn just in case.
 
Do you have a spare set of carbs?
I could try the 360 mods for mid range issues
 
I wish I did! I would love to see what you come up with!

I will try out your mixture suggestions over the weekend and let you know how it works out. My Bore-Tech ignition arrived today. I definitely
think I will get new Dyna coils to run with it. I am suspecting poor spark in the left cylinder is a partial cause. The change in sparkplug boots
and cutting the wire made a difference.
 
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