Tanaka 2 speed gearbox

[Thepartsguy]

Is there even a carburetor on that thing? I would try to fire it from the primer cup only. Then polish and paint and detail it and put it in my living room to look at.

The only carburetor I have that will fit is a clinton carburetor.. Bolts right on.

I will most likely just stick it back on and make sure the idle is set so if I do try to fire through the primer it won’t be wide open throttle.

 

[Hellion]

Can you refurbish the carb that's on it?

I'd have no qualms about your plan. Put the whole shebang on a minibike, a classic minibike for that post-war feel. Maybe an Azusa if I were starting from scratch, but one of those Popular Mechanics style specials with the bicycle parts would be cool. In other words, make it a low performance, low stress sort of machine just like this pleasant ad...

 

[ezcome-ezgo]

Fascinating project all right. Marketing targeted directly at grandfathers.

 

[Thepartsguy]

Can anyone tell me what the big brass trumpet looking piece is??? And why when i pull the pull cord it makes pressure and vacuum??

Correct me if I’m wrong if I started this wouldn’t it rev really high pulling air in through this?

 

[Thepartsguy]

Can you refurbish the carb that's on it?


View attachment 155111

The carb on it was like brand new inside. I put the bowl back on tested the needle and seat and stick it back on so the butterfly won’t let it run wide open if it start on the primer.

 

[Thepartsguy]

The engine fires exactly one time. That’s it… Plug outside of the engine will spark once then show zero signs of life. It will kick off once every time.

I find a new plug it bet it stays running. It’s an AC 85t sparkplug. Big threads.

 

[Hellion]

Can anyone tell me what the big brass trumpet looking piece is?

You mean you don't know? It sorta reminds me of a draft tube(?) for crankcase blow-by. It's pointing down so water doesn't collect inside.
But I do not know.

 

[Denny]

That’s a 2 stroke so you may have to take that pipe and bell looking thing off to get it to run. Or plug it up.

 

[Thepartsguy]

The engine runs and it runs very well. I needed a new spark plug. I’m working on the idle circuit for the carburetor so it continues to run.

I’ll mount it all to a plate and hook the gearbox to the engine sprocket and get video of it working.

Then I’ll just hold it until I find a mini bike. I see it as the engine was locked up and not going to be saved easily. Now that it works I gotta make something that runs and moves with it. If it breaks there really wasn’t much there when I started.

 

[Denny]

Mix oil 25:1 in the gas.

 

[Thepartsguy]

Mix oil 25:1 in the gas.

Absolutely and a small hint of 30w mixed in also.

The carburetor on it now is junk. It won’t run it very well. I’m looking for an easy in house replacement now.

 

[Thepartsguy]

I need an expansion chamber and a suitable carburetor. I ran the engine for a few minutes today.

It will run and rev fine if you set there and blip the throttle. Let off and it shuts off like the idle circuit in every carburetor I try is plugged.

I suspect a pipe/carb more suited for a small 50cc could help a lot. But I don‘t have either of those on hand. I’ll order some parts off the bay and modify them to fit.

If that doesn’t work crank seals? It starts easy enough and will rev fine just dang thing will not idle. Doesn‘t even try.

This would be a top notch mini engine if I could just get the dang thing to idle.

 

[panchothedog]

Looks great. You got that thing figured out and running very fast. Good job.

 

[Thepartsguy]

Looks great. You got that thing figured out and running very fast. Good job.

With the flywheel spinning the correct way the output of the transmission spins backwards.

So i would have to mount the transmission in the front of the engine. it’s mounted in the back right now. And it would all be placed into a mini bike backwards.

The flywheel would be spinning the opposite direction from a normal Briggs and it would even pull start backward but through the transmission would still push the bike forward the correct way.

I’m trying to say it would be a weird mini bike.

 

[Denny]

You know 2 strokes can run backwards with no ill effects.

 

[Master Hack]

You know 2 strokes can run backwards with no ill effects

I believe the ignition timing would have to be adjusted.
5 degrees BTDC ccw rotation becomes 5 after with cw rotation. I remember something like that from a long long time ago.
Doesn't qualify as an ill effect tho.

 

[Thepartsguy]

I believe the ignition timing would have to be adjusted.
5 degrees BTDC ccw rotation becomes 5 after with cw rotation. I remember something like that from a long long time ago.
Doesn't qualify as an ill effect tho.

I was wondering about the flywheel magnets being reversed if it spun backwards

 

[Master Hack]

The fact they are turning opposite direction wont matter, it'll still make spark, just not at the right time. It would still run, just poorly.
You could....
If you can get your hands on a timing light, (remember those?) make a mark near TDC start it normal and reverse and ckech the difference.
Then relocat the coil by the same amount. That may or may not be practical.

 

[Master Hack]

Just one of my half baked thoughts, ya did make sure the piston is installed in the right orientation? Thats a port timed engine....
Sorry didn't mean to get too basic. I've seen it happen.

 

[Thepartsguy]

Just one of my half baked thoughts, ya did make sure the piston is installed in the right orientation? Thats a port timed engine....
Sorry didn't mean to get too basic. I've seen it happen.

it’s in the bore correct and this is a copy of a villiers engine. So the flywheel is timed to the coil plate with a mark and the coil plate is timed to the block with a mark.

Once running a timing or strobe light can be connected and it’s just like watching the balancer on a Chev.. All the marks are already there from factory to use with a timing light. I don’t know when it’s supposed to fire though. They measure in like 1/8 before Tdc and weird measurements like that.

It’s the carb being to big or faulty.. OR the crank seals are bad. The coil produces a jolt that HURTS.