Surging Hobbits

I've brought back a 1983 PA 50ii from the dead. But still not able to get it up over 15 mph. Bike runs great, but slow. When I give it full throttle I feel an intermittent surging. She feels like she wants to go, but something is holding her back. Replaced the roller weights up front as they were shredded. My next guess is that the culprit is the rear pulley. I've taken it apart and the interior looks pretty gnarly.

If that doesn't do the trick, what would you recommend next? CDI box? Carb?

Thx

Re: Surging Hobbits

Did you clean the carb? When you say surging do you mean the engine cuts out or do RPMs just fluctuate?

Re: Surging Hobbits

Clean the carb, check fuel flow, pull the filter tray out some.

Re: Surging Hobbits

some very helpful info was given to me when i got my hobbit.....clean the carb, clean the carb again..... and again...and again.

it took five complete thorough cleanings b4 my hobbit ran right. kehlins can be rough..

Re: Surging Hobbits

Once clean they are extremely reliable and trustworthy. It's sitting around and getting varnished that puts them down and out.

Re: Surging Hobbits

^ Very true. He does say the bike runs well but "drags" at 15, front weights were shot, and back pulley looks bad, I bet that could be the hang up...I guess we will see if he reports back.

Re: Surging Hobbits

Thanks for all the help. Carb is brand new from 77. Jetted as directed on this site. But that doesn't mean a little tuning wouldn't help. When I say surging I mean that when I give it full throttle it will top out at 15 mph at most but occasionally will get a surge of 3 or 4 more mph and then back down to 15 mph. I've been thinking that the front plate is trying to close but rear pulley won't open and give enough extra belt. But I'll rule that out tomorrow.

Re: Surging Hobbits

A brand new "stock" carb is asking for clone tuning troubles. Clean the original. Don't have it? Get an original. You're likely rich as hell. The drive train will not "go back" once it has gotten some more travel. You won't surge to a higher speed and the go back down. If you have the power to hold a speed you will hold it.

Re: Surging Hobbits

Have you pulled the petcock and cleaned the screens?

Mike

Re: Surging Hobbits

Broken rear pulley will have that surging feeling when it wont downshift properly. Does it shift smoothly? Or does it slam into high gear hard?

Re: Surging Hobbits

I took the pulley apart and it was pretty sludgy as shown in the pic. Hosed it down with degreaser and got it spic and span. The shifting is basically non-existent. Front variator might close a few millimeters but that's about it. Didn't have time to reassemble, but I think i'll lube it up and give it a shot next weekend. As for petcock question, I'm using a new tank and petcock/screens for a 50cc dirt bike that I found online. Original tank needs to be de-rusted and coated, but haven't had time.

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Re: Surging Hobbits

Yea of You're not shifting I bet your rear pulley broke the welds, its a pretty common problem.

Re: Surging Hobbits

I spent yesterday cleaning out all of the dirt and grime. Now that the pulley is all clean, I notice that the ears on the outside of the cam follower and inside of the pulley look to have ground together a bit and are pretty jagged. Is this what you mean by breaking the welds? Is it worth trying to smooth these surfaces out a bit or should I look for a replacement in better shape?

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Re: Surging Hobbits

Looks like you're missing at least one chunk of your cam follower. Here's what a new one looks like/costs: https://www.treatland.tv/OEM-honda-hobbit-pa50-driven-pulley-cam-follower-p/oem-pulley-cam-23231-148-672.htm

Re: Surging Hobbits

the cam follower is just shot at a bad angle. it has all three lobes, but each of them are pretty chewed up. the one on treats is cheap enough that i may not bother with trying to file this one back into shape. but the one on treats seems to be missing the oil seal. any idea where i might grab one of those?

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