Re: hobbit shuts off like a like after WOT

Brent Bublitz /

Stop with the infrared thermometer. That will not tell you the proper temps. In any case it does not sound like you are overheating and seizing.

The Hobbits, Express and express II come ridiculously over jetted to begin with. The #1 problem I have had with every single one I have owned (4 now) is a clogged exhaust because of the stupidly rich jets. Put the stock jet back.

It's quite possible you still have an electrical issue. When you say you swapped out the condenser and stator, did you swap for new parts, or used? A bad coil on the plate or condenser would act exactly like this.

Re: hobbit shuts off like a like after WOT

The float is plastic and shouldn't be adjustable. But, check and adjust your idle air screw properly by tuning the screw to the highest idle speed and snappiest response then setting your idle back down to whatever you want.

Re: hobbit shuts off like a like after WOT

angry monkey /

Just finished longest run before failure. Put stock jet in, adjusted carb ran great. Hit top temp 350f. Plug also fresh and as before no black just a marshmallow brown discoloration. But in the end still cutting out. Run time approx 20 minutes.

Re: hobbit shuts off like a like after WOT

Brent Bublitz /

Can you immediately restart, or does it have to sit for a while?

Re: hobbit shuts off like a like after WOT

angry monkey /

Immediately with choke.

Re: hobbit shuts off like a like after WOT

angry monkey /

Let it run for 5 secs kick of choke then off again.

Re: hobbit shuts off like a like after WOT

angry monkey /

Down jetted one more step. The hobbit just did 40 minutes continuous with no issues. Much slower off the line but winds up nicely to near same speed as higher jetting. Guess kit and variator and clutch mods are the way to go if I want to die on a moped. Thanks DPC.

Re: hobbit shuts off like a like after WOT

Rather than go even lower than the normal jet I would just pull the filter tray out a small bit. This will give you some tuning variance when the weather gets colder or you feel you are lean. What altitude are you at? The owners manual will state that a size lower jet would be used above a certain elevation (thinner air, less fuel).

Re: hobbit shuts off like a like after WOT

angry monkey /

Michigan so elevation is not extreme. I'll try air filter tray as I do still feel she's running a bit lean. what is optimal running temp on the pa50ii?

Re: hobbit shuts off like a like after WOT

Hobbits run hot in general but on a stock cylinder you will not be making extreme heat. The pipe will increase output and rpm will be much higher than stock so you can expect hotter running but still want to keep it reliable. Most kitted bikes run just under 380's-420~max (some go much higher) due to poor cooling head design. I would shoot to keep the bike in the 350-375 range at continuous wide open running but if it were to climb a bit higher on an incline I wouldn't be scared. You really want a head temp gauge to see that though.

If you are sure your timing is right then you can keep it safe by running just a bit rich, mocha or so on the plug. My stock jet with the Proma looked exactly like this without an air filter tray (taped the tray hole up) and one of the snorkel holes plugged to compensate for the lack of filter restriction.

Re: hobbit shuts off like a like after WOT

angry monkey /

Came to an unpleasant pause yesterday. Took her out for a long test run. Running 340-360 WOT. Hit a long uphill stretch. 3/4 of the way up sputter and stop. 450+ temp. Cooled down with immediate restart. Got her home threw the ped up in the air for inspection. After reading the last post I finally noticed the complete absence of the snorkel. I had the bike in the ped shop a month ago and you would think I would have noticed the ease at which the carb can be removed with it not there. Maybe that's why it always felt like I was running lean. Now I have clean power from start to WOT. Running temps no higher than 325 and took that hill again without hesitation.

Re: hobbit shuts off like a like after WOT

Excellent. I bet you also now realize just how sensitivej etting is to intake/filter restriction . Once you become aware of all of the factors that take part you will gain a much keener understanding of how your bike is working. Some people never understand it.

Re: hobbit shuts off like a like after WOT

angry monkey /

Yes. Thank you for the walkthrough. Might be ready for a real build now.

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