n.e.r.d

iTrader: (6)

My JP B5 has been dormant for more than a year now, and I'd like to run it again.
Problem is the rear bearing is gummed up, perhaps due to leftover fuel..
I can turn over the crankshaft, but it feels pretty tight.

Easiest solution would be to change the rear bearing, but as this is a JP option ceramic bearing, I'll try to salvage it.

Any ideas to de-gum a gummy bearing?
Thanks in advance!

sschultz

iTrader: (15)

Carb cleaner, compressed air.

Hoese37

iTrader: (5)

Soak it in fuel.

Jaz240

iTrader: (52)

Oh man I thought this thread said Gummy Bears! I love those things

-R2-

iTrader: (4)

Ha, I thought the same thing, OPEN YOUR EYES!!!!!

dooug1960

iTrader: (6)

how fn long would one have to chew a gummy BEARing

i had same issue used brake cleaner and re lubed it spins like new now

Werks

iTrader: (3)

It's probably from the castor oil in the fuel. If you can remove the bearing carb cleaner and compressed air will do it. Just spray it out, then drop it in a small cup, spray with carb cleaner and let sit for 5-10 minutes then give it a quick scrub with an old toothbrush, spray again to clean off any clinging gunk and blow off with compressed air and it should be good as new. Last step put a few drops of after run oil on it and spin it to coat the steel races to prevent rust and re-install.

n.e.r.d

iTrader: (6)

Thanks everyone for your replies!
i guess the easiest way to clean the 'GUMMED-UP' bearing is to remove it from the crankcase. I'll prolly have to get my LHS to do it for me..
Otherwise, any way for me to clean if the bearing is still in the case?
Thanks again in advance!

ps:- do those gummy bears still exist?

Mauve

iTrader: (3)

Remove the carby, piston, sleeve and rod (pretty easy to do) then pop it in a container of Kerosine up to just below the carby section, let it sit over night or two nights. Pull it out of the Kero, drain it and blow it out with a compressor. Job done. The kero wont damage anything it will soften and dissolve the caster oil that is gumming up the bearing. If the bearing has rust on it, replace it and the front bearing straight away. Corroded bearings will let the rust go when running the motor which will result in a warn out piston/sleeve and crank.

sschultz

iTrader: (15)

You do not have to remove bearing from case. Just make sure all O-rings are removed from case. Remove carb and intake O-rings as well. carb cleaner, scrub-a-dud-dub, blowjob, lube, DONE....
Chances are, if they where gummed up, they where protected from rust, but, inspect anyway to be safe.... good luck...

n.e.r.d

iTrader: (6)

Thanks for the tips,
You guys have been very helpful!

wombat

iTrader: (31)

Probably not such a good idea leaving the crank and PSR in with this method if his engine has a silicone filled crank, carb cleaner will affect and most likely damage the silicone putty.

n.e.r.d

iTrader: (6)

I'll take out everything, carb, PSR, crankshaft so that I'm left with just the crankcase and the 2 bearings in it.
Then try to clean the rear bearing from there on..
Are brake cleaners (for automotive use) good to get rid of the gum? Those can-type where I can just nozzle spray directly at the bearing..

And what is this carb cleaner that everyone keeps talking about?
Hobby or automotive stuffs? I'd think that it's for hobby use as no modern cars use a carburetor nowadays..

Jaz240

iTrader: (52)

Go to Walmart and get a can of Brake Cleaner. It's $2.25 here in Arizona. Just make sure it is Non-Chlorinated because the one with chlorine in it will eat away your plastics. The best thing to do would be to hold a heat gun into the back plate hole for a few seconds to loosen up the hardened Castor oil. Do not spray anything in there until it cools off a bit though as pretty much anything aresol is flammable!

wombat

iTrader: (31)

Carb cleaner is designed for automotive use, one of the harshest/strongest chemical solvents out there, and will get off almost anything. They still sell tons of the stuff as people use in things like older vehicles, carby motor bike engine, lawnmowers etc.

Brake cleaner should remove the gum build up on that bearing and is a lot less harsh/safe to use than carb cleaner - designed for auto brakes use so it doesn't swell up things like rubber seals etc (in hobby use though - given thickness/size/type of rubber used in seals when compared to auto-specific rubber seals, not sure if the same applys)

I would still rip the bearing out and then use carb cleaner to get it squeaky clean; wouldn't go down the road of using the 'in-situ' method someone suggested as even brake cleaner may have an effect on silicone filled cranks - hell even the JP website states the following:

WARNING: Do not put the shaft inside solvent or gasoline for cleaning.
This liquides are able to damage the red dough.