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Worn carb parts
Posted: Fri Nov 20, 2015 10:18 am
by AlanH
I took my car to have the engine looked at by Geoff Bloor in Nottingham.
He managed to set it up quite well but one of the things that he came up with was that there was play in the throttle spindles.
We got talking and he said that this wear was greater due to the lack of lead in petrol.
This got me thinking, we get our heads modified, if needed, to take unleaded but what about elsewhere? Should we use lead replacement anyway?
I'm going to replace the spindles (I hope that I don't need to do the bushes) and I wonder if it would be worth putting some thin grease on them.
Re: Worn carb parts
Posted: Fri Nov 20, 2015 10:28 am
by mahony
Must admit i have never heard unleaded petrol causing throttle spindle wear before

Re: Worn carb parts
Posted: Fri Nov 20, 2015 11:34 am
by cliftyhanger
That don't make sense to me. There is no petrol flowing through the spindle/body.
New spindles usually help a great deal. If the bodies are that worn it is easier to buy a decent set rather than try to get yours rebushed. Grease will get sucked out at some stage, but won't hurt.
Re: Worn carb parts
Posted: Fri Nov 20, 2015 2:53 pm
by Jon Tilson
Early carbs with sideways pulling return springs last about 40k miles before wear makes idel adjustment difficult.
The later type with concentric springs last well over 100k.
Jonners
Re: Worn carb parts
Posted: Fri Nov 20, 2015 11:04 pm
by AlanH
I've got the spindles, is it worth soldering up the overrun valves?
Re: Worn carb parts
Posted: Sat Nov 21, 2015 7:04 am
by cliftyhanger
Yes. And then chop the back bits off them too.
Re: Worn carb parts
Posted: Sat Nov 21, 2015 12:20 pm
by Jon Tilson
Or just buy plain discs and knife edge them.
Jonners
Re: Worn carb parts
Posted: Sun Nov 22, 2015 7:06 pm
by Richard the old one
When I top up my carb dampers I normally drip some oil down on the carb spindles in the hope that this will help to lubricant the spindles and so reduce the wear. It can't do any harm so its worth doing.
Re: Worn carb parts
Posted: Sun Nov 22, 2015 9:43 pm
by AlanH
When I top up my carb dampers I normally drip some oil down on the carb spindles
Good idea !
Re: Worn carb parts
Posted: Sun Nov 22, 2015 9:57 pm
by AlanH
What is Knife edging Jon?
Re: Worn carb parts
Posted: Mon Nov 23, 2015 12:05 am
by Jon Tilson
Filing the edge of the discs to a thin edge like a knife blade.
Jonners
Re: Worn carb parts
Posted: Tue Nov 24, 2015 6:01 pm
by Dollyby 2
Hi folks,I don't wish to appear to hijack this
thread but I to have problems with worn spindles,bushes and carbs in general on my 1500 hl.Should one be able to stall the engine by turning up the the two nuts on the jet's to the last, I did this and it still seems to be running rich and is rough on idle, about 800 revs,is the wear in spindles/bushes responsible for this,regards to all, Myles.
Re: Worn carb parts
Posted: Wed Nov 25, 2015 12:17 pm
by Jon Tilson
Check your float valves. Overflowing chambers is the biggest cause of rich running.
After that look at collapsed waxtstat pellets if you have waxstats.
Also check the choke linkage isnt causing the jet to stay down. Alos very common.
Try pushing up on the bottom of the jet. If it moves up the choke linkage is sticking.
Jonners
Re: Worn carb parts
Posted: Wed Nov 25, 2015 1:58 pm
by Dollyby 2
Hi Jonners,my carbs are non waxstat,the number on both floats is Fzx1258f, what does this denote to?.I am not very familiar with su's,the choke is disconnected and both sets of clamps are loose also,there is some play in the spindles.I will check float levels when I get a minute or three,I presume this means taking the lid off and a visual.Would centering the jet/needle help? thanks so much for your help.Regards, Myles.
Re: Worn carb parts
Posted: Wed Nov 25, 2015 5:01 pm
by AlanH
Check the breather/overflow outlet on the top of the float bowls, if that is blocked the pressure will cause rich running.