Old school flat fix

[David Fyffe]

I have one of those-------somewhere

 

[W0QNX]

I have a new unused one out in the big box of parts in the shed. They should not be used on fuel injected engines. In the old days before fuel was injected the breather part of the pump let air pass much easier than the carb would so mostly gas free air was sucked into the chamber and pumped out into the tire.

The pumps worked fast because each stroke on a 250 single was 250cc's of air. That's a good sized compressor stroke.

I guess if you could stop the injectors from spraying fuel (pull the pump fuse?) you could still use one of these on a new style bike but a small compressor would be easier.

 

[SMSW]

I remember those. Wonder if it can still be had?

Look on ebay and FB - places where old tools are sold. You might find one used.

Did those old kits have metric adapters that will work in today's spark plug holes?

 

[maddog13]

Now since I’ve acquired an old school ride again, with tubes in the tire, and a small, special battery, about the size of a deck of cards, with no way to attach either a battery tender, or air compressor, I thought about carrying CO2 air, but the decided to look into my vintage, never been opened boxes, and low and behold look what I found!
Wonder how many old timers here remember these?

Will it work on a single? I thought you used to put it in one cylinder and the start the bike on the other one.

 

[Igofar]

Look on ebay and FB - places where old tools are sold. You might find one used.

Did those old kits have metric adapters that will work in today's spark plug holes?

They come with 10,12,14mm adapters.

 

[Igofar]

I have a new unused one out in the big box of parts in the shed. They should not be used on fuel injected engines. In the old days before fuel was injected the breather part of the pump let air pass much easier than the carb would so mostly gas free air was sucked into the chamber and pumped out into the tire.

The pumps worked fast because each stroke on a 250 single was 250cc's of air. That's a good sized compressor stroke.

I guess if you could stop the injectors from spraying fuel (pull the pump fuse?) you could still use one of these on a new style bike but a small compressor would be easier.

 

[Igofar]

It does work on fuel injected bikes.
I simply turned the fuel off and let it run out of gas.
The vents open to the air pull in fresh air from outside etc.
I tried it on an inner tube from my crf250l, filled it up way faster than a slime pump!
A minute or two and it was at riding pressure.
Only took about a dozen kicks to get there.
I then released the air to see if it smelled like fuel, and didn’t smell anything, ymmv.

 

[OldMcClelland]

yeah, but what did it TASTE like????

 

[Igofar]

yeah, but what did it TASTE like????

Not fuel!

 

[Andrew Shadow]

In the description posted by OBO in post 5, the contents of the combustion chamber are not pumped in to the tire. If the description is correct, the air doing the compressing and the air being compressed are kept separate from each other, so the presence of fuel in the cylinder shouldn't be an issue.

 

[W0QNX]

In the description posted by OBO in post 5, the contents of the combustion chamber are not pumped in to the tire. If the description is correct, the air doing the compressing and the air being compressed are kept separate from each other, so the presence of fuel in the cylinder shouldn't be an issue.

Except Obo's post is deceptive in how it works. The cylinder contents are indeed pumped into the tires. As Igofar posted if he shuts the fuel off then all is good. I was just posting to let folks with bikes like the ST to know it's not going to be great for bikes with fuel injection and no gas shut off valve. I figured Igofar had some way to use this pump safely.

Larry's pic with the instructions says: This engine air pump has it's own intake ports through which cool outside air is drawn into the PUMPING CYLINDER. If you understand the design it's a simple design that works good but it does use the engine cylinder as a pump.

Back years ago when electric 12V pumps were not so good and took forever we carried these engine pumps for the big 3 wheeler and dune buggy tires.

 

[Andrew Shadow]

Except Obo's post is deceptive in how it works. The cylinder contents are indeed pumped into the tires. As Igofar posted if he shuts the fuel off then all is good. I was just posting to let folks with bikes like the ST to know it's not going to be great for bikes with fuel injection and no gas shut off valve. I figured Igofar had some way to use this pump safely.

Larry's pic with the instructions says: This engine air pump has it's own intake ports through which cool outside air is drawn into the PUMPING CYLINDER. If you understand the design it's a simple design that works good but it does use the engine cylinder as a pump.

It certainly seems like it would be impossible to prevent fuel from entering the tire using a fuel injected engine, certainly if it is running.
I'll stick with an electric pump, but if you have no alternative having some fuel in tire to get you home and purging it there is better than not getting home.

 

[Igofar]

It certainly seems like it would be impossible to prevent fuel from entering the tire using a fuel injected engine, certainly if it is running.
I'll stick with an electric pump, but if you have no alternative having some fuel in tire to get you home and purging it there is better than not getting home.

If the petcock is turned off, (no flow of fuel) and the ignition is turned off, (no spark to work the fuel injection) How would the fuel be injected into the engine?
If the bike were running, I could understand it, even if the ignition was turned on, then maybe the fuel injection would squirt fuel in there if the throttle was opened etc.
But on a dead/empty cylinder how is this a concern?
Just wondering.

 

[Andrew Shadow]

If the petcock is turned off, (no flow of fuel) and the ignition is turned off, (no spark to work the fuel injection) How would the fuel be injected into the engine?
If the bike were running, I could understand it, even if the ignition was turned on, then maybe the fuel injection would squirt fuel in there if the throttle was opened etc.
But on a dead/empty cylinder how is this a concern?
Just wondering.

I stated on a running engine. If you have figured out to run an engine with the fuel and ignition disabled you are more talented than I.

 

[Igofar]

You don't run the engine.
Your simply using the kick start lever to pump air.
Which is why you have the ignition off, and why no fuel is involved.
If you figure out how to run a single cylinder, kick start only engine with the pump hose attached, sucking air, and get the engine running while you use the pump, then you my friend, are more talented that I.

 

[Andrew Shadow]

You don't run the engine.
Your simply using the kick start lever to pump air.
Which is why you have the ignition off, and why no fuel is involved.
If you figure out how to run a single cylinder, kick start only engine with the pump hose attached, sucking air, and get the engine running while you use the pump, then you my friend, are more talented that I.

No problem achieving that Larry, I would just connect it directly to my Turbo Encabulator.

I was referring to the description that references using it on multi-cylinder engines where the engine is kept running to pump the air. Regardless of what method is used, ending up with air/fuel mixture in the tire if there is no other choice is a better option than remaining stranded in the middle of no where. Having this option on a motorcycle like yours where an electric pump may not be practical or viable is a nice option to have available vs the alternative of having nothing and being stranded.

 

[Igofar]

Yup, getting stuck out in the middle of the desert is no fun
I've even made it home on dirt bikes by stuffing grass, dirt, or sand in the tire, then zip tying the tire to the rim, just to protect the rim while riding slowly home, with thoughts of "why didn't I carry my spare tube with me today?"

 

[bdalameda]

I have one of these stuffed away in my garage somewhere. Back in the 1970's I remember changing a tire on my BMW R90s on a trip in Utah and using it. I used it on one cylinder and started the engine and ran it on one cylinder while it inflated the tire. It worked great. At the time I did not worry about pumping fuel vapor into the tire.

 

[Valker]

Those don't pump fuel or combustion air into the tire. The compression in the cylinder operates the little pump inside the mechanism. Only fresh air is pumped into the tire.