Nitrile tipped float needle on BS 38s

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I got lucky with my CB500t when I built it and managed to fit brand new later nitrile tipped float needles originally made for another bike, effectively curing or considerably offsetting future float needle wear.

I may need to replace the float needles on my BS38s from a TX650 and was wondering if anyone has done it with later nitrile ones and from what bike they used? The nitrile needle I put in the CB500t is wider and longer and thus too fat to fit in the BS38s.

Are the BS34 needles the same dimensions as the earlier BS38s float needles? The BS34s are nitrile tipped.
 
I remember seeing a post some time ago where someone did find a compatible tipped needle valve but I cannot for the life of me find it now.

Maybe have a search for Viton tipped valves as this is the best material for the job. Allen's performance, in Notts, may be able to help?

Hope this is of some use.
 
I had a look at that thread and it suggests the GL1200 (and also same for many other bikes) float needle will fit on an XS-2.

My only concern is the XS-1 and XS-2 float needles and seats are different to the TX650 ones. Mikexs and other sites seem to think so and yet other sites seem to think XS-1, XS-2 and TX650 are all the same...
 
That's too bad but now we know. By how much does it not fit? Too long, wide etc? Could you post up a pic of both side by side with dimensions? Would help a lot on this sort of query.
 
Its too wide. Photos attached.

Please note I cannot confirm on the XS-1/B, according to Mikexs these are different, this is for a TX 650 '73.

Annoyingly Mikexs wish to charge $45 shipping to the UK for the float needles, something I know costs $6 via USPS to the UK, I have managed to get them to send stuff via USPS before, it really depends on who you are talking to on the other end of the email as its not in their system.
 

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Ok I'm trying to get a work around for this, I pulled of the float valve seat from a CB500t (which is a very common part among other Hondas) it is much deeper and has a wider orifice than the TX650 valve seat and luckily it screws into the TX 650 BS38 carb (same pitch etc.).

This allows me to use the viton tipped float needle, my only concern is the orifice for the valve seat in the BS38 carb is fairly shallow (compared to the CB500t) and the CB500t valve seat is longer so it might sit too high and stifle fuel flow.

Here are the photos of them side to side, and the CB500t valve with the GL1100 viton tipped float installed on the BS38. So far tested with air all good, will be testing with fuel tomorrow, I think it should be ok.
 

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Good luck with that carb, it looks nasty. The needle jet in particular looks like shit. It was brass colored at one time, hard to tell that now, lol. It seals into the carb body using a small o-ring which I bet is toast from the looks of the jet itself.
 
5twins said:
Good luck with that carb, it looks nasty. The needle jet in particular looks like shit. It was brass colored at one time, hard to tell that now, lol. It seals into the carb body using a small o-ring which I bet is toast from the looks of the jet itself.
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Yes I know, its the gasket that actually makes it look bad also, it is hard but actually perfectly clean other than the orange discoloration and doesn't leak so it'll stay on until I get a replacement. If I took the rubber gasket off it'd look much better.

As for the needle jet I agree, although it appears to be locked solid with the carb body I tried unsuccessfully to remove it didn't want to go further for risk of damaging it, I've had worse condition carbs start a bike fine, just want to get the bike started at this stage.
 
So far tested with air all good, will be testing with fuel tomorrow, I think it should be ok.
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Ok so it worked, I got the bike started, however when I left the bike for a few days when I tried it again it wouldn't start whatsoever. Looking into it now.
 
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Ok so there is no carb overflow now but still the cylinders were flooded.

The GL1100 seat and float needle swap appear to have worked, however I'm still trying to identify the source of the problem.
 

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