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Cylinder head air compressor

Dustin Maki

Just got it firing!
Joined
Mar 7, 2021
Messages
7
Location
Memphis
My 2000 Jackal is returning to its roots and devolving into a tractor bit by bit as I experiment doing dumb things to it. I came across and decided I want something like that permanently on my 'used to be a bike'. I don't want exactly that thing because I want to keep both spark plugs in.
I was wondering if I could drill and tap the cylinder head for a small 'compression release' fitting to serve the same purpose.
Let me know if you have ideas about:
where in the head to drill for the fitting, which cylinder
how to make it affect compression ratio as little as possible
what kind of 'pump' to use
how to temporarily stop fuel injection to that cylinder and keep it running
I'm thinking a dummy load resistor shorted across the injector wires.

If you want to say its a bad idea, I know, tell me how to do it less bad. I want to learn from this.

 
Think about if you are ever going to want to sell your bike. Everyone prefers unmolested bikes, or ones with credible documentation.
Way past that point. I'm a wheelchair user cutting and re configuring to suit my acquired riding style. If it ever gets sold, it will be for parts after I'm gone.
 
Way past that point. I'm a wheelchair user cutting and re configuring to suit my acquired riding style. If it ever gets sold, it will be for parts after I'm gone.

Fair call, I was unaware of your situation.

However, your current method of pumping up tyres requires the removal of a spark plug (until you get around to your proposed modification). I used to use the Schrader Spark Plug Air Pump too, until more convenient devices became available.

Have a look at these. https://shop.slime.com/collections/tire-inflators.
 
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I was very confused until I looked at the video - is this for use when you are out and about , and get a flat ?
Getting air back in the tire will be the least of your problems, but it might give you the opportunity to get some pressure back in the tire and keep getting you closer to home or a fix...

As Mr. Kiwi suggests there are other alternative to drilling a hole in the bike available.
Little 12v pumps, the slime kits he linked to take your pick.
 
Ive got one of those schrader pumps, bought it about 30 years ago and kept it in the back of the car, seemed like a good idea at the time, never used it. Compressors are cheap now, got a big one in the garage and take a small one when away on the bike.
 
Why try and do all that hullabaloo when a portable air pump can be had for like $10 ?

Fair question. Its not just for pumping up the occasional tire. Its for inflating lifting bags, air over hydraulic cylinders, filling tanks to use air tools in the field, T shirt cannon. Tractor stuff. I burn up those little electric things pretty quick and the alternator and battery aren't really big enough to support larger ones.
 
Does anyone know what the duty cycle and CFM output is Of the bike cylinder pump ?
What kind of out put was it designed to support ?

Was it built to support the kind of use your looking at ?
 
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My 2000 Jackal is returning to its roots and devolving into a tractor bit by bit as I experiment doing dumb things to it. I came across and decided I want something like that permanently on my 'used to be a bike'. I don't want exactly that thing because I want to keep both spark plugs in.
I was wondering if I could drill and tap the cylinder head for a small 'compression release' fitting to serve the same purpose.
Let me know if you have ideas about:
where in the head to drill for the fitting, which cylinder
how to make it affect compression ratio as little as possible
what kind of 'pump' to use
how to temporarily stop fuel injection to that cylinder and keep it running
I'm thinking a dummy load resistor shorted across the injector wires.

If you want to say its a bad idea, I know, tell me how to do it less bad. I want to learn from this.

If you want to drill an extra hole, that would be the same procedure as making your engine twin spark on one side. Problem is that between the push rod tunnels there is only space for a 10mm spark plug which is really small. To actually tighten that plug you would need a turned down thin wall deep socket, that's how tight it is in there. You machine a hole any larger than that and your push rods will see day light...
On top of that, the square head oil feed is right were you need to be so the passage needs to be plugged and a round head style 'front feed' oil line needs to be accommodated for by welding, machining, drilling & tapping.
Let's say you do all that, now you still need to know if for example a hollowed out 10mm spark plug will pass enough air to do what you intend to use it for.
Hope this helps. JR
 
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