TOPIC:

Doing some further work, investigation & fine tuning on my carbs.

Question:-

Has anyone had any good, bad or indifferent experiences with CHOKE PLUNGERS as seen below. Any feedback or experience relating to these is welcomed & valued !

Thanks

Pete F

Hi Pete,

While I was chasing my over rich conditions I suspected the plungers but in the end they were fine. My problem was caused by the plastic floats that had absorbed our alcoholic fuel and were now allowing the fuel level to over flow into the intakes.
My short answer is that they seem to work fine.

Bill

As ever, thanks for your reply Bill.

Hope you are good & well ?

Pete F

I believe these are the factory Mikuni style vs the choke plungers without the guide pin, as found in the after market kits.

I've used both and never had an issue, as long as the rubber portion is sealing at the bottom of the choke bore.

Being that there are the two styles out there, I have always wondered if the OEM version was better, but so far I haven't seen any performance difference.

T.

Thanks for info Toddh

I've just fitted the ones without the pin to my carbs - I was wondering if the pin made any difference.

OK,

I bought & fitted the new choke plungers to my carbs as part of a pattern carb set I bought 2 years ago on Ebay.
The kit looked very good & was not expensive, but I did not inspect each component including the plungers in very close detail before fitting as I was pleased overall with the quality of the parts in the kit.
The bike ran to a satisfactory standard since fitting the kit (but a bit rich) & I had no reason to question the kit in as most 1300's run rich.

Over the winter I stripped the whole top end & replaced the rings, valve stem oil seals & re-lapped the valves to eliminate oil burning.
The bike is now running 99% perfectly & not burning any oil at all.............but the plugs are burning very rich, dry & black........too much fuel despite the carbs being set perfectly as ever on pilot & main.

This is the reason why I am now digging much deeper into the cause of this & now looking much closer into the carbs as the obvious culprit, as everything else has now been renewed & replaced.
Today I got to the choke plungers in very close detail & was quite surprised what I found which is in the photos I took this afternoon shown below.
The photo shows the ORIGINAL plunger on the RIGHT & the newer pattern one on the LEFT.
Look very closely at the differences............they are pretty obvious & very distinctive.

I have also measured the height at the top of the plunger of the pattern plunger when sitting on the very bottom of the plunger tunnel, versus the height of the original plunger & the pattern one sits over 1mm higher, despite being exactly the same overall length.
This means there is a definite gap around the base...........which would allow MORE FUEL past when the choke is off.

THIS WOULD DEFINITELY CREATE A RICHER MIXTURE ALL THE TIME DUE TO MORE FUEL BEING ALLOWED INTO THE INLET TRACK WHEN THE CHOKE IS OFF.

The obvious differences are far too vast to ignore. The whole design & profile of both ends of the 2 plungers is completely different.......far too much to ignore.

As a result, I have now put the original plungers back into the carbs & will test (if it ever stops raining) in the back-side of Europe.......the UK