Honda Hobbit 20mph model

So I picked up another Hobbit at a swap meet, and it turned out to be a 20mph model.

I hear there's just some washers you can take out of the drive assembly to make it a 30 mph model. What exactly do I need to do to fix that?

Thanks for any help.

Re: Honda Hobbit 20mph model

well as an old teacher of mine once said, "it aint that simple" pfft anyway you gotta actually do some machining or cutting on the existing pa50-i variator plate, that or just up and replace it with the plate from the pa50-ii model, the idea being that you want to work the 50-i plate to look more like the 50-ii plate. someone wrote a good piece on doing the modification; i think you can find it by searching in the performance tuning forum.. if its not there search moped repair.

Re: Honda Hobbit 20mph model

The other problem is that the I models had a 10mm carb and the II models had a 12mm carb. The variator plate mods might get you a couple of mph though.

Re: Honda Hobbit 20mph model

theres a lot of little differences..

The PA50I has milder cylinder port timing.. Stock compression ratio is actually _higher_ on the PA50I than on the PA50II. It's rear wheel gear box is also geared lower.

And then there's the variator.. Personally, i'd avoid the popularly suggested method of machining the PA50I variator to get a higher gear. Any mistakes can't be corrected.

Essentially all of the important things regarding top speed have to be modified to transform a PA50I to a PA50II and isn't worth the effort, imo... but it would be nice to have a PA50I as a spare-parts bike.

Re: Honda Hobbit 20mph model

So if I get a PA50II variator plate, a performance exhaust, and possibly a 13mm carb would it be getting up past 30? Or will the rear wheel gear be holding it back? Would that be hard to replace too?

This engine looks brand new, there's not a speck of dirt on it. I'd hate to see it just sit there while I put the parts on a less-mint bike.

Re: Honda Hobbit 20mph model

The cylinder porting is different too. You would have to port it out. Transfers are cut lower and raising transfer roofs without screwing them up is always difficult.. but the easy way might be to shim under the cylinder and shave off the top of the cylinder, thus raising both the transfers and the exhaust.. I'd have to look it up and check-see if that alone would do it. I don't own a PA50I so can't check directly. Another easy way might be to swap cylinders .. might be .. depends on a lot of things that need to be carefully measured first..

A stock 11.5mm Keihin carb from a Pa50II should bolt right up but i'm not positive.

Going from memory, the PA50II variator and mainshaft has 2 flats where it slips on. An additional flat would need to be machined on the PA50I shaft. afaik, shaft diameter is the same.

Then substitute a PA50II rear wheel / gearbox and that should do it.. but i get the feeling i'm forgetting something(s).

A performance exhaust would surely help but i wouldnt wanna get stuck with a really loud bike that only goes 25mph. I would see the total transformation as a serious project. Swapping parts seems like the easy way.

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