Stiff throttle

[vern401]

A friend of mine has this problem. He has asked this on a forum. it is quoted from his post.

"My cb750 is coming along and running nicely.  However my throttle seems uncomftably stiff. Not at first but after a good 10-20 miles my wrist is aching from holding it open/twisting.  The cables are brand new and without being looped into the push/pul on the carbl are smooth and easy with no binding.  On the carbs the spring/throttle is pretty stiff and I can barley move it by hand.  Is there an adjustment there?  Lube?  Or am I just a weak fish.  6"3 218lbs"
His bike is a 1974
Is there a way to take some pressure off the spring? It has the carbs simelar to My CB750F 1978

My spring is also hard to move so I have the same problem he has.

[Re-run]

Oh common issue. Not much you can do but some have tried different springs but it is a crap shoot finding one that fits.

What I have done is lube the shaft as it goes through the carbs. With your cables, are they honda or motion pro? If new honda, supposedly they should not be lubed as they have a teflon liner. Motion pro do not.
Lube is needed. What seems to work is a tennis ball cut in half and a hole drilled in just big enough to seal around the cable. Fill with a little oil and hang up. the oil will seep through and lube the cable. Kinda messy but does a good job. Might help a bit.
My throttle was so easy to turn after I did this I only needed 2 fingers. That was 2 years ago and needs to be done again though.

[vern401]

Thank you again... I'll relay it to him...
you can add me to yahoo messenger if you like i have the same name as I do on here.

[fourwheeler04073]

I just bought motion pro cables and can't believe how stiff they are, what kind of lube do you recomend? and are you talking about the shaft on each carb?

[Re-run]

I bought motion pro cables a couple years ago and kinda regret it. I know honda cables are more but they work so much better. Anyways, motion pro cables need lube but any cable lube will work.
I got a cable lube tool and there is a hole for a straw. It works ok but have a rag around the tool to stop the mess. Spray slowly and small bits at a time. Hang the cable for a while to allow the lube to flow down. Have a rag under the cable. Once it drips through, slide the cable and is should be smooth.

It seems to me that the motion pro push cable(closes carbs) is a hair too short and it causes binding sometimes. You have to be very careful routing that cable.

[fourwheeler04073]

Thanks Re-Run, have you messed around with the return spring at all? it seems like its to strong I was going to go to a hardware store to see about a different spring. I unhooked mine and the throttle was alot better, except it was slow to close. I'm not running stock bars, I have some z bars on it now and the cables seem to be an ok length, I'm going to change to a drag bar though because I'm hardtailing it.

[dave Esch]

I had the same issue, and my throttle would actually stick open. I had to push the throttle off every time. Although I admit, having poor mans cruise control was really nice at times. Anyway, I used fuel hose and clamped it to the cable. I filled about a foot of the hose with pb blaster and hung it overnight. The difference was absolutely amazing. The throttle snaps back now. i don't have that issue with my carb springs tho. Is that an f series problem?

[TOOLS1]

I replaced the spring on the Toolmatic when I rebuilt the carbs. I found one at the local hardware store that was the same length, but a lot lighter. It just adds a little tension to the throttle. I can now cruise, for hours without fatigue. i have always preferred having to close the throttle manually myself.
TOOLS

[Re-run]

I never changed my spring, I figure my hand will get used to it and it does. The F spring is the same way, some just do not mind the tension while others dislike it.
As tools said, he went to a hardware store and found one. You could make one out of piano wire too I would imagine.