Throttle Valves.

[ggray]

While synchronizing my CL77 carbs per LM's instructions, I noticed that the RH throttle valve was higher than the LH valve when both were at "Bottom". Spring action seems good and both valves move at the same time when the throttle is twisted. Both throttle adjusting screws are backed out all the way in the attached photo.

What might cause this condition and which one is correct, LH or RH?

How might this affect my idle and performance.

Anyone have a remedy for this?

Thanks,

Gary

[jensen]

Hi,

I ckecked mine (CB 72'67) and both valves can reach the bottom (mechanical).

You could disasemble the top, loose the cable from the valves and see if there's any mechanical reason why the valve is not reaching the bottom. If there's a good reason then it maybe original (intended), if not the problem is the cable (Idon't have a CL to check, neither do I know if carbs on the CL are in any kind different than a CB72).

Idle : if it's idling with a high rpm, it does have effect, if't does idle o.k, not.

More importent is to synchronise the carbs, not the hight differences between the valves.
It is not said that both valves have the same hight when synchronised, it can differ a bit, but if synchronised properly both carbs produce the same vacuum and thus flow (if yetting is o.k.).

The best performance can be found when the carbs are synchronised, mixture over the entire rpm range is o.k (not to lean and not to rich), good working ignition mechanisme according to specifications. and the engine is in good mechanical order (head and pistons).

For the best resullts check on a dynojet

jensen

[LOUD MOUSE]

The problem looks to be the cable on the right side carb. May be the cable end at the carb isn't in the slide slot correctly or ya may have to look at the cylinder where the cables go from one to the two for the carbs. May be one is pulled a little from the splitter and not allowing the slide to go to actual bottom. ........................lm

While synchronizing my CL77 carbs per LM's instructions, I noticed that the RH throttle valve was higher than the LH valve when both were at "Bottom". Spring action seems good and both valves move at the same time when the throttle is twisted. Both throttle adjusting screws are backed out all the way in the attached photo.

What might cause this condition and which one is correct, LH or RH?

How might this affect my idle and performance.

Anyone have a remedy for this?

Thanks,

Gary

[ggray]

I'll take a look at the cable and get back with results.

Thanks,

Gary

[jwbert]

I had this problem with one of my carbs as well, turned out someone had probably dropped one of the slides and it was bent on the bottom ever so slightly. The bent area would not allow the slide to seat all the way into the groove at the bottom of the carb cylinder. Filed and straightened the area and it now seats properly. JWB

[ggray]

Thanks JWB....Looks like the carb is coming off as the cable(s) checked out OK.

Gary

[ggray]

I pulled the RH carb off last night and disassembled the throttle valve fron the cable/spring assembly. Throttle valve went all the way to the bottom of the carb bore (Could tell by looking into the engine side of the carb and seeing the valve bottoming out on the trepanned groove at the bottom of the bore.)

I did notice however when removing the valve/spring/cable assembly from the top of the carb that the cable appeared to have gotten wound around two or three of the spring windings, or visa-versa.

I made sure the cable went through the ID of the spring on reassembly and it now appears to look identical to the LH carb at full bottom.

Thanks for all of your input.

Gary