Mikuni Hsr 45 Ap stuck

[Timetrader]

Hi folks,ive got a Mikuni Hsr 45 that im cleaning/rebuilding.It was put away years ago without ever draining the carb,All is well except the accelerator pump plunger/spring is stuck/frozen in the bore where it lives in the bowl.Its been cycled in an ultrasonic cleaner,soaked im pb blaster and compressed air.no joy.Any thoughts,Thanks

[JSD]

Motorcraft decarbon can works unreal 

[seehogs]

I believe it is called (motorcraft) X66.I have had luck with
pine-sol heated to about 170 outside! Seems to dissolve most gas and
brass residue. A couple of hours max!
May have a corroded aluminum hole,would have to remove plunger
to clear.
Drill and tap plunger to remove

[Timetrader]

I did wind up drillin a small hole in the aluminuim plunger and installed a self tap screw maybe a 1/4" down then secured some needlenose vice grips on screw and pulled plunger out of bore.The bore was scored up pretty good.If the situation was on the road it could have been made to work with a file and some jb weld for the plunger,but thats not the case so a new float chamber bowl,plunger and spring in addition to a rebuild kit.parts and pieces were about $115.00 total.its reinstalled on scoot and all is right as rain.

[seehogs]

I have been in that spot before. Never had to
replace bowl but most bores are not that bad.
I little hone with a dremal and some fine paper
makes it all better.
That piston can be pretty loose in bore and still
make a big squirt. (Sorry)

[Timetrader]

For what its worth,ive seen an hsr leak fuel at the Accelerator pump rod/boot area from what i would say is excessive fuel past the ap plunger from wear,scoring?,that memory went into the decision to buy new.Squirt is one issue,leaks are another