Concentric slide siezing

[a101960]

Not my carb I hasten to add - it's on a Triumph! My mate's carb slide has started to become lazy in returning when he closes the throttle. If the carb has distorted can it be "undistorted" or is it a right off?

John

[RichardL]

Learned here on your favorite forum: carb distortion is often caused by overtightening the mounting nuts (as I think you know). Weak spring? Sticky cable? Gunky fuel? Throttle control friction screw too tight? Overheating head with no thick gasket?

OK. I'll back off and let the real carb specialists take over.

Richard L.

[chaz]

is it running air filter?
working on one at moment and  slides fine with filters on, took them off to see how it ran ( per manual) and slides stuck open.
filter back on and slide ok.
you can get them re bored and oversize slide or anodized, but in the end with new jet, float, valve, gaskets you might as well buy new carbs.

[muskrat]

Just back the nuts off 1/16 turn to see if it helps.
Cheers

a101960 wrote
"Problem solved. I went to have a look to see if I could find anything that was causing the slide to stick. It is efinol. The slide was covered in a horrible tacky varnish like substance, as was the needle and jet. My mate then told me that over the winter he had had the tank lined. Oh dear!

John"

Topic split and named tank liner

[BSA_54A10]

Not my carb I hasten to add - it's on a Triumph! My mate's carb slide has started to become lazy in returning when he closes the throttle. If the carb has distorted can it be "undistorted" or is it a right off?

John

Yes.
John Healy did a long treatise on this subject over on the Britbike forum.
He even showed a photo of his distortion removing tool and provided dimensions & instructions

[wilko]

By the way, "I" before "E" except after "S" 

[muskrat]

Good one wilKo, now we're starting a spelling slant. I failed English.
Cheers

[BSA_54A10]

By the way, "I" before "E" except after "S" 

Way back when I was an undergraduate I got picked for a survey on reading, writing, spelling & retention.
the humanities department did these ever year as part of ongoing research.
The spelling tests were standard 100 word tests +1 for right -2 for wrong and were tailored to the course of study.
My result was -60 which was on  par for an engineering student from a state school.
Oddly enough on the "pick the wrong word test" I got a good score ( also typical for engineers )

[Tiger Dave]

Learned here on your favorite forum: carb distortion is often caused by overtightening the mounting nuts (as I think you know).

Yes, overtightening the mounting nuts will distort the body and cause the slide to hang up as the OP described.

My simple remedy is to insert some bolts into the mounting holes with from the front so the heads of the bolts stand proud from the mounting face. 

Then, I place the carb body in a bench vice so the vice is pressing on the bolt heads and tighten the vice ever so gently to "undo" the distortion that was caused by overtightening.

It takes very little pressure to straighten the body until the slide can pass up and down easily again.

Just don't overdo it.

[muskrat]

G'day Dave,  .
Thanks for sharing your remedy, I'd never thought of that way.
It happened to me yesterday. Some rug rat in the carpark must have given the twist grip a try. Kick, kick, kick, why won't this start, then noticed limp cable. Spanner in pocket undo nuts 1 flat, tap body, click slide drops, tighten nuts  , all good.
Cheers