Throttle cable stiffness

[Multiman]

And onto another issue.

My throttle is stiff to turn and returns to closed very slowly.

I think its due to the angle the pull cable makes with the throttle "butterfly" if thats the right word.

I've attached a picture so you can see.

How can I improve the situation please?

Cheers

Tim

[Sesman]

I would agree. That cable holder has been used and abused. It needs bending back to stop the cable inner binding on the outer. It may not cure your problem, but that needs sorting as a start.

[Multiman]

I'm getting quite good at removing and refitting the carbs

Has anyone got a picture from a similar angle, of what the cable holder should look like.
I think I know what I'm looking to do but every little helps!

Cheers

Tim

[McCabe-Thiele (Ted)]

This shows how the angle should be - no cables fitted.

carbs 400 by Macabe Thiele, on Flickr

[Multiman]

Thanks Ted that’s brilliant.
Mine is a huge way out compared to that.
I’ll report back

[McCabe-Thiele (Ted)]

This photo should give you a better idea of how the bracket itself looks I think its just those two side screws that hold it onto the manifold.

In the photo the mechanism is loose but you should get an idea where your bracket is bent / out of shape - or if it's not the correct one.

carb bracket 400 by Macabe Thiele, on Flickr


.400 carb bracket by Macabe Thiele, on Flickr

[Multiman]

Thanks Sesman and Ted.

After sticking it in the vice, applying a little heat, threatening it with long handled grips and lots of trial and error I've got to this.....
Hopefully that will be a lot better on the bike

[McCabe-Thiele (Ted)]

Well done that should improve the throttle action if the cables are all good as well.

[400 Cafe Racer]

Thanks Sesman and Ted.

After sticking it in the vice, applying a little heat, threatening it with long handled grips and lots of trial and error I've got to this.....
Hopefully that will be a lot better on the bike

What I found with mine after I removed it completely for inspection and light oiling, was that there were no kinks or bad bends, but that the inner lining must have melted and expanded causing the inner cable to bind, even after running oil right through.  Worth checking if you stiil have some friction over the full travel before you refit it.

In view if this I have routed the new cable so that it does not go through the "Guide Eye" on the cambox cover, which will reduce any heat transfer from a hot cylinder head vicinity. Checking the cable after a good run confirms it is not getting hot now.

Dennis 

[andy120t]

Is the 'guide eye's a 400 thing? It would be interesting to see a piccie, but it seems sensible to avoid a heat source.

[McCabe-Thiele (Ted)]

I thought the guide eye is just for the clutch cable.

[Oddjob]

I thought the guide eye was for the clutch cable?

Check the back of the workshop manual for the 350/400 in Ashimotos Dropbox, there is a cable routing guide at the back, iirc, the cables go through the speedo/tacho bracket hole, down around the left side of the headstock and pass through the hole in the frame where the coils sit. Throttle cable routing is critical on the Honda fours, get it wrong and the cables wear against the frame and the action is a lot heavier than it should be.

If taking the cables off in order to reroute them I’d suggest removing them entirely, hanging them off a door and dribbling some silicone oil down the inner cable, not engine oil, must be silicone as that won’t cause the Teflon lining to swell and make them bind. Get it right and pulling the inner up and just letting go as they hang from the door and the cable should just slide down under its own weight. Check the outer cable for damage at the same time. If you find a part of the outer that shows it’s scuffing against the frame cut some fuel line if you have any spare longways and fit it around the cable so the fuel line rubs and not the cable. Protects bothe the frame paint and the cable.

[Nurse Julie]

I thought the guide eye is just for the clutch cable.

You are correct Ted, it is for the clutch cable, not throttle cables. The throttle cables go through the guide attached to the horn bracket.

[Oddjob]

Just checked and that routing was for the 500./500. The 400 has them going under the clocks, coming down the right side of the headstock, through the wire clamp fitted near the coils and then to the carbs.

[Multiman]

After fitting the carbs back on the throttle stiffness is better but not perfect.

I've got some brand new cables so I'll lubricate with silicone lubricant, hang overnight and experiment with cable routing to see if I can improve things.
As they stand the cables are super free so fingers crossed