PA50 variator nightmare

I got my '78 Honda Hobbit running last weekend, but the variator is stuck in low gear. I have removed the large nut, ramp plate, one weight, and one weight clip. The the screws in the other two clips are starting to strip. Does anyone know a good way to remove these screws? Also the movable part of the variator pulley is stuck. Does anyone know a good way to free it up without damaging the engine? I am also open to buying a working variator if someone has an extra one. Lastly, does anyone know where to get one of those flywheel holders that the Honda manuals refer to?

Any information will be greatly appreciated .


Re: PA50 variator nightmare

i used an impact driver before i stripped them cause they sure felt like they the heads were going to strip.. those screws are tiny and tight... might be some LocTite on them but i forget.

First i attached a 1/2 to 1/4 inch adapter to my 1/2 inch impact driver and then a 1/4 inch socket.. mighta been a 5/16ths .. i inserted a hex-bit phillips into the socket.

A couple light taps and the screws loosened enough to use a hand screwdriver.

First find out where/why the variator is stuck. If it's rusted to the central shaft try some WD40 overnight and a light soft hammer around the perimeter. It took me a day to loosen a rusted one .. but the innards were trash anyway.. the weights and their groves were extremely worn.

Re: PA50 variator nightmare

I always use locking pliers when old screws are starting to strip, just dont lock them too hard, sometime they will break completely.

maybe you dont have a lot of place for pliers there, but try to turn the screws little by little...

you can also get pointy locking pliers...

they look like crocodile pliers but are locking...they help a lot!

Also, i may have a variator in the next 1-2 week...

my 2 pa50 will become one and i will probably have one variator left...if i got 2 good ones.^..

but they are 30mph version, if yours is 20mph version, you'll probably have some grinding to do. but you'll get more speed too

hope that helps


Re: PA50 variator nightmare

Thanks for the advice. I soaked the variator with penetrating oil and tapped it with a rubber mallet for awhile, but still nothing worked. I tried my needlenosed vicegrips too, but no luck there. The variator is corroded to the shaft that it slides on. The ped hadn't been run since 1978 and only has 26 miles on it, so the weights and ramps are in good shape. I was afraid to use an impact driver as I thought that a blow to the variator might damage crank bearings or seals. I'm considering screw extractors or drilling the heads out, then twisting the threaded portion out with vice grips. Crazy screws! I already replaced the ones on my intake manifold with bolts. I wonder why Honda chose to use screws instead of bolts on their bikes and peds. The ped is a 20mph version, so I would have to mod it abit. What has to be modified to make a PAII variator work with a PAI?


Re: PA50 variator nightmare

here we go sean...

sorry if the link doesnt work...

copy past it if it doesnt work


Re: PA50 variator nightmare

if you know it's corroded and rusted to the shaft just keep working on it.. be in no hurry and gentle with the hammer. Eventually it'll move a hair and then you can go a little faster with it.. i been there done that. The variator i worked on was sitting outdoors in a junkyard for many years. Let it soak.

If you're careful you can salvage it.. if not.. not.

Re: PA50 variator nightmare

haha. I was just on that site looking at that same picture. :)

Re: PA50 variator nightmare

For the weight retaining screws you will have to bite the bullet and do whatever you have to do to eventually get them out.

If the phillip heasd are all rounded out you can try an extractor. Sears sells a pointed sharp edged extractot that you gently tap into the damaged heads and then back out.

I think that the tapping also helps break the thread bond.

There are a couple of penetrating oils that I have had success with in the past. The best stuff is called KROIL. You apply it and let it sit for a day and presto! The KROIL is hard to find as it is normally sold in industrial supply stores.

The other stuff is Liquid Wrench. It is a little less effective but give it a try.

The movable part of the variator has a brass sleeve inside of it so the shaft must be rusty. Keep working on it. It will eventually work loose.

Forget trying to find that puller. You will probably have to make one. Of course it is probably metric left hand threaded. To hold the engine from turning I used a strap wrench or chain wrench that can be wrapped around the pully while you are removing the nuts.

Good luck

Re: PA50 variator nightmare

Allen Murphy /

You can order KROIL online at

The shit is just fantastic--it will disolve and free up corroded parts I NEVER thought would come loose!

Al Murphy

Re: PA50 variator nightmare

I just wanted to update you guys on my variator situation. I kept spraying it with penetrating oil and tapping it with a hammer. Spray, spray, spray, tap, tap, tap... finally it began to move a little. I stuck one foot on either side of the variator and pulled like hell. It popped off - It sent me flying backwards and just about put the ped through my brother's car. I took my Millwaukee drill from hell, stuck a wire brush on it and polished all of the pulley surfaces until I could see my reflection. As for the little screws that hold the rollers in place, I ended up taking my Dremel and cutting slots in the heads. I then took a big straight slot screwdriver and twisted them right out. After I purchase some screws, I'll put it all back togethor and see what happens.

I'm curious though, the variator looks like it slides on a bronze oilite type bushing. It looks as if it will wear quickly if I don't keep it lubed. What do you guys suggest using on it. 3in1? WD40? Lithium?

Thanks for all the help!

Re: PA50 variator nightmare

i lube mine once every blue moon. I think that bushing is oilite.. anyway it's just sliding friction.. not like it's spinning on that shaft. Now that yours is kinda rough from corrosion it might be wise to oil it often.

As far as replacing the little spring-keeper screws, i did some modifications a while back, testing different weight rollers during which I ran without the keepers.. Never noticed a difference in shifting due to the lack of the little flat springs.

By far, the major impediment to the rollers moving outwards is the squeezing pressure of the pulley/movable plate (caused by the strain on the belt). Those little springs do nothing by comparison. I think the flat springs may be just a manufacturer's assembly aid, but i'm not certain.

Re: PA50 variator nightmare

"I think the flat springs may be just a manufacturer’s assembly aid, but i’m not certain."

That's what I was thinking. But what the heck, I think I'll replace them anyways. :)

Re: PA50 variator nightmare (update)

Well, let me start by saying "Happy New Year, blah, blah, blah." On to the update. I found some new stainless steel screws and lock washers at the hardware store, wire brushed all the internal parts for the variator, lubed it, and stuck it all back together. The variator works great now and I've managed to get my little PA50 up to 12 mph, but I've still got a problem. The ped runs great once it starts, if you leave the throttle alone. The engine will progressively run faster and faster until it levels out. The problem is when you twist the throttle, it speeds up for a second, then bogs badly, then almost dies. If you give it a minute it will speed up again. It acts like it can't deal with the amount of fuel that's being dumped into the cylinder. I am going to disassemble the carb and clean it out again. Anyone got any thoughts on what's going on?

Also, it was running really smokey and fouling the plug when I was running the mix at 32:1. I'm running it at 40:1 right now. Is this enough oil? I also increased the gap on my plug and leaned out the carb. After running it for awhile, the electrode on the plug is a light gray color. Am I running too lean? What should the plug look like if everything is adjusted correctly?

On a happy note, I managed to score a pair of original PA50 mirrors, which I promptly stuck on. Does anyone have any of the plastic cover parts they'd like to sell.

Damn this is a long post. :)

Re: PA50 variator nightmare (update)

i got the idea this was a new toy and you hadn't gotten into the engine yet. Have you pulled the head and taken a look at the internals yet?

Aside from mechanical problems, it does sound like it could be carburation.. Instead of flooding, maybe opening the throttle allows a lot of air in but no fuel. What does the plug look like after it stalls and dies? Wet or dry? If it's wet, is it oil fouling or fuel fouling..

12 MPH top speed? I wouldn't bother trying to get the oil ratio worked out till it's running half way decent. 32:1 is ok for now.

Re: PA50 variator nightmare (update)

I haven't opened up the engine yet as the ped only had 26 confirmed by original owner miles on it when I got it. The plug was wet when it was fouling out, but since I switched to a 40:1 mix and leaned the adjuster screw out, it hasn't fouled out. The plug went from being black and wet to light gray and dry. I'm just wondering if I'm running it too lean. There was one piece down in the center of the carb (main nozzle) that I forgot to remove and clean. I suspect that this may be my problem. I also reused all the old gaskets and O rings. I wonder if I have an air leak in the carb body or something.

Re: PA50 variator nightmare (update)

all those things are possible.. a gasket or O-ring leak or a clogged 'emulsion tube' above the main jet... Any leaks of air or gasoline or any air/fuel restrictions anywhere can cause weird stuff to happen.

Even with low mileage, gasoline left in a carb for a long period can solidify and clog something up.

You can "blow" the long brass emuslion tube out if you have a compressor. Remove the main jet and put air pressure into one of the two little brass tubes in the air intake horn. (i forget which one) The emulsion tube might pop out.

Or you can reach into the carb's throat with a pencil or something soft (wooden) and push down on the tube's end (you see it sticking up into the venturi. That will get it started on it's way out. It's just slightly friction fit in there. The main jet holds it in place.

Re: PA50 variator nightmare (update)

I soaked the carb in solvents, washed it out with water, then blew the heck out of it with compressed air at 100 psi before reassembly. The carb is actually made up of parts from two PA50 carbs (PA50 I and PA50 II I believe.) Is there a difference in jet size or the floats between say a '78 PA50I and an 80's PA50II? I wonder if crossing the parts screwed something up. Can I use any kind of RTV sealer when reassembling the carb or should I just use the O ring gasket?

Thanks for the replies so far!

Re: PA50 variator nightmare (update)

Stock main jet in a PA50 II is a #78. I never owned a PA50 I so i can't say what they come with. My guess is it's .. i can't even guess. I don't know exactly how Honda restricted the PA50 I to 20mph. Honda may have provided both modles with all the same stuff except for the variator (which i know is different).

If the carbs are different and you swapped parts. obviously that could be a problem.. something as simple as improper float level can make it go lean or rich.

Regardless of cleaning methods, the carb has to be disassembled and examined to be sure it's clean. I found a scrapyard PA50 and the carb was clogged from end to end including lots of garbage up above the main jet.

If you're gonna be swapping parts and making due with what's available, the price you pay is that you need better than average knowledge about how all this stuff is supposed to work.

Re: PA50 variator nightmare (update)

Check to make sure the float bowl on the carb is on in the correct configuration! The fuel vent tube should be to the right side when assembled. It can be assembled 180 deg out. This is not covered in the tech data.

Re: PA50 variator nightmare (update)

Good point.. i have put the bowl on the wrong way more than once but i dunno what it does.. probably messes up the float's ability to float.

Btw, it's covered but in an offhanded manner.. The manual talks about the drain screw that you loosen to drain the bowl. It is accessed through the front sprocket and through a special little hole in the swingarm.

For that to be possible the bowl must be mounted like you said.. with the drain hose nipple (and the drain screw) on the right side of the carb.

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