1978 honda hobbit

I just got a 1978 honda hobbit from my buddy and it runs for a couple of seconds when you squirt starting fluid in the cylinder so I 'm asumming that the carb must be dirty but I don't wont to take the engine off again to get to the carb because its a pain in the ass to get it back on, so does anyone have any other ideas about what could be wrong.

Also if anyone else has this moped or knows alot about it whats up with the airbox? wheres the filter? it looks like the carb is just up against a piece of metal?

Re: 1978 honda hobbit

You are going to have to drop the engine. Do a search in this forum for a couple of ways to take the engine out.

The air filter is inserted into the frame from the left side of the bike under the belt cover. The air goes into the rubber thing then down and back up thru the filter then into the carb.

When you clean the carb and oil the sponge, squeeze as much of the oil out of the sponge as you can.

Clean every passage and jet in the carb.

Also it is helpful if you get the repair manual.

Re: 1978 honda hobbit

Shawn Mcdonald /

I was just in my garage and I got the moped to run for like 5 minutes but it only went 10 mph and it ran crapy....should I clean up the carb

Re: 1978 honda hobbit

Unless you're running with the choke closed, there's no way around it .. And when you do clean the carb, do it right.. no shortcuts.. or you're gonna have to do it again.. i'm speaking from experience along with all the other PA50 owners around here.

as a matter of fact you better plan on getting the entire fuel system from the gas cap down to the engine block in perfect shape.. no vacuum or fuel leaks, no fuel restrictions, no loose dirt or rust anywhere, etc.. these bikes are sensitive to fuel delivery problems and the penalty is you drop the engine again and again..

Search this forum's archive extensive PA50 tune up items.. i doubt there's a question that could be asked that hasn't been asked and answered.

Re: 1978 honda hobbit

I have actually posted this before. You DO NOT have to drop the engine on the Hobbit to get the carb out. I can pull the carb out in about 10 minutes. First loosen the upper engine mount bolt(the long one that mounts the engine to the frame). Disconnect the spark plug wire and decompression cable, drain the fuel bowl, loosen the hose clamp on the fuel line at the carb(turn fuel off before doing the last two steps). Then loosen the throttle cable at the carb. Then get a piece of wood like a 2x6 and cut it to about 30 inches. Then place that board under the front tire parallel to the tire. Now get some thick boards (4x4x6) or a bunch of thinner ones. You need one for each end to go underneath the 2x6. Two 4x4's would be nice. Basically you have made a jack for the front end of your ped. Now you have the room to remove the four screws and the carb. A phillips head that can be used with a ratchet and an extention is the best way to remove the screws. Sears or most auto parts stores will carry that tool.

Re: 1978 honda hobbit

huh?

you don't have to drop the engine but unless i'm mistaken you just dropped the engine..

Re: 1978 honda hobbit

Dropping the engine sounds like you are disconnecting all the bolts that mount it to the frame, taking off the muffler, and removing the drive belt. Can you see why the terminology you used could be confusing to someone who doesn't know how to fix mopeds? In cars, when you drop the transmission you take it out away from the car.

tricky..

heh.. ok.. technically you didn't "drop the engine". You raised the frame..

but seriously, thats ok ..

i prefer to drop the engine to the ground.. the bike will balance on the muffler but will tip over easily.

Re: 1978 honda hobbit

the engine drops when you remove the front pivot bolt.. i don't know how else to describe it.

The swingarm sorta pivots on the rear shock mounts.. but the engine definately drops to the floor.

Re: tricky..

The engine stays mounted to the lower frame and stays above the ground because the center stand keeps it from falling to the floor. I hope Shawn gets this advice and figures out it is not that hard to clean the carb on a PA50.

Re: tricky..

The engine stays mounted to the lower frame? Now i've lost you..

The engine has one bolt holding it to the frame.. it's the large pivot bolt it hangs from. You cannot remove the carb unless that bolt is removed and the engine separated from the lower frame.

Retracting the centerstand allows the engine to drop away from the frame.. Or you could raise the front wheel and so raise the frame...

I have 3 frames i'm willing to cut up and have been searching for a modification that would allow carb removal without disconnecting anything ..

But that airbox is a structural member of the swingarm and can't be made removable.. it prevents the carb from moving backward..

And anyway, access to the carb attachment bolts and nuts or reed valve block bolts is a pain anyway... and the tubular frame itself will not be easy to cut/weld/bend/ or modify .. its a tough problem..

But I did call Midas and the guy said he could bend me a new frame tube from suitable tubing.. But i'd essentially be building a new frame .. a huge job and not worth it.

Re: tricky..

Shawn Mcdonald /

Well whatever all I know is that I cleaned the carb and I still have a problem. The moped only runs with the choke on and not good either. any suggestions

Re: 1978 honda hobbit

Shawn Mcdonald /

Does anyone know how many turns in the carb screws are suposed to be...

Re: 1978 honda hobbit

Just out of curiosity, did you replace the spark plug with a brand new one yet? You'd be suprised how often a bad plug will show similar symptoms.

_only runs with the choke on and not good either_

Choking off some air brings the air:fuel mixture closer to being correct .. fuel is restricted. I can picture a tiny piece of junk partially blocking the main jet .. some fuel is getting through but not enough...

There's no point in adjusting the idle speed screw or idle air-mixture screws at this time.

For reference, my carb is clean.. bike runs great.. Speed screw is turned out exactly 3 turns (bottom it out and then back it off). Idle mix screw is 1/2 (one half) turn out.

But this is my bike .. yours is gonna be different. Get the engine good and hot before adjusting idle. The 2 screws only affect idle.

Re: 1978 honda hobbit

Make sure the float bowl in on correctly, ie, with the little vent tube facing to the right as you sit on the bike. It can be installed 180 deg out and look right but clearly won't run!

There are also fuel line filters inside the fuel tank that you can access by removing the petcock. These need to be clean and clear. What is the status of the tank? Rusty?

Re: 1978 honda hobbit

Shawn Mcdonald /

I did replace the spark plug with a new one when I got the moped, and I will clean the carb really good 1 more time and post the results

Re: 1978 honda hobbit

what he was saying about dropping the engin by not dropping it works well baciscaly you are using the shocks as the pivot instead of using the motor mount i tried it last night see attachment

1123775223_pa50_motor_drop.jpg

Re: 1978 honda hobbit

I would think that the bike would fall over if you tried this, but if you throw a rope over a rafter in the garage this should hold it up.

Re: 1978 honda hobbit

Shawn Mcdonald /

Fix the problem it turns out last time I cleaned the carb a missed a little peice of dirt but now I have a new problem my gas tank has some rust in it what should I do about that

Re: 1978 honda hobbit

Take the tank off the bike.

Remove the fuel tap and clean the screens real good. If the screens are bad replace the tap with a new one or put in an in-line fuel filter.

If the tank is not leaking go down to the hardware store and buy a handfull or a box of 1/4" nuts.

Wash the tank out with a lot of water with a hose.

After it has dried, pour the nuts into the tank and make like a martini shaker.

Shake the nuts out and flush again with the hose.

Do this a couple of time if necessary.

After all the water has dried out reinstall and you should be good to go.

The oil in the fuel should keep the tank from rusting any further. The rust came from water accumulated by condensation while sitting so long.

Re: 1978 honda hobbit

actually it'll sorta balance on the muffler .. but it's better to have something or someone hold it steady while lowering, raising or working on it.

In this photo i raised the front wheel for extra clearance some reason .. can't remember why. Nothing is suporting the bike.

1123793176_bike001.jpg

Re: 1978 honda hobbit

best thing is to clean the tank's interior as best you can and then Kreem it .. it'll prevent future rust from flaking off.

I've got a bike with a very rusty tank .. it even has (patched) holes rusted all the way through. There isn't a prayer of getting all the rust out so more will always form... but it's under the flexible Kreem coating and can't get into the fuel.

Don't Kreem the gas cap ..it's two tiny holes need to be open to vent the tank .. speaking of which theres a good chance the interior of the gas cap is rusted badly and may not be venting (air gets past the old, dried rubber gasket instead) .. but cross that bridge when you come to it.

Re: 1978 honda hobbit

Patrick Mattison /

closest manual/ only pa 50 manual I can find

may help

http://www.mopedriders.org/html/manuals/honda/pa50sm/honda83pa50manual.pdf

Re: 1978 honda hobbit

the pa50 manual is awsome i suggest going t o the local library and printing it off (if they dont charge for paper) and put it in a binder

Re: 1978 honda hobbit

How much rust? If your tank has a little rust and you don't want to Kreme it you could add a fuel filter (gauze type, not a screen type) between your tank and carb. Be warned that rust particles can be very small and will slowly accumulate on your carb jet, resulting in clogged jets after a while. It's not hard to clear the jets but requires opening the carb, taking the jet out and blowing air through the jets to clear everything up. Rust will also accumulate in your float bowl as a fine powder once it dries, easy to clean if you have the bowl off anyway.

Re: 1978 honda hobbit

There's already a very fine screen around the petcock inside the tank .. and another extremely fine screen filter on the bottom of the petcock, externally accessible.

An additional filter down stream from those won't matter.

Any tiny particles that get through those screens will get through the mainjet and will be burned .. it's how it was designed and intended.

Re: 1978 honda hobbit

Thanks joew. I got it now.

Re: 1978 honda hobbit

Shawn Mcdonald /

I got the moped running and from what I've read the PA50II should go 30 but mine only does 20

Re: 1978 honda hobbit

Things to check:

1. clean your air filter. after re-oiling, squeeze it out between paper towels as dry as you can get it.

2. make sure that your throttle is opening the carb butterfly all the way.

3. with the left side variator cover off, observe that when you rev the engine the pully comes fully together and the belt is wihin about 3/16" of the top of the pully.

4. Check your timing.

Let us know.

Re: 1978 honda hobbit

Shawn Mcdonald /

I know where the air filter is but how do I get it out

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