Bit of an odd one.... LPG conversion

I am thinking of converting my 750 Seca to run on LPG, with the rising fuel costs here in the UK and the advantages of going "green", I think it will be worth it.

Just wondering if anyone on here has converted an XJ to run on gas.

Only problem I can see is storing the damn stuff in a conveniant location without it being too exposed or in the way.

 

My thoughts are- - become good friends with a fork lift repair man.
And you'll never tune it to get 80 HP and great throttle response.
It'll be a plodding, soggy 40 horse, with it's own character flaws.
But it'll burn clean, start right up in the damp, and never dirty the oil.

How would you work out "reserve" ??
because forklifts just plain die on their last breath of gas !!

 

I'm on a stupid 33 BHP restricted license anyway, would still keep a petrol tank of some kind.

Main idea is to be able to ride about cheaply, can just fill up from the red propane bottles, no fuel duty, no tax on that duty and the insurance and vehicle tax benefits from going green.

 

I doubt you'll have the success you want trying to adapt the LPG to the OLD Technology ... essentially DESIGNED to run on Gasoline and Gasoline alone.

But, I do think that you would (or should) be able to INVENT and Manifold and Throttle package that will allow you to use LPG as an alternative Fuel.

I also think you should inquire at a breaker to see if you can acquire the Fuel Injection Bits that some later model 750 were equipped with. That should make your quest somewhat easier with regard to actually delivering the Fuel to the Engine during testing.

Good luck!
I suspect that there are a few like you quite busy looking for a way to power a Motorbike with Bottled Gas.

Don't linger on trying to convert Carbs intended for Petrol.
Devise an Injection System similar to the early Bosch K-Jet with Manual Air Flow metering to keep the need for Electronic's to a minimum.

 

I thought about possibly using the vacuum points on the inlet rubbery bits to deliver the gas, a nice tidy and out the way solution, and could really be fitted without any modifications to the bike, except the the addition of a bottle of gas and bolting on a regulator and bits.

 

Stephen Chastain covers the conversion rather well in his book "Generators and Inverters". He lists commercial carburetors and also shows how to build your own. His web site is http://www.stephenchastain.com/book6.htm

 

Let's see, mounting an LP tank on a bike? No thank you.imagine if it went down? "KERPOW!!! I don't think the insurance company would go for that either. Good luck with your indever.

 

I understood that if you can locate a proprietary make, they have to meet some pretty hefty safety standards. I've no idea how heavy that will make a tank, but if you're down to 40bhp, that's still plenty for 80mph cruising on the motorway and then some. If you need more oomph for a bit of playing about you can switsh back to petrol. I hadn't thought that there was this much of a hit on power output, though.

If it works, I've got a 750 and sidecar that could be in line for a conversion - plenty of space for a tank in the back....

 

my continuing thoughts are- - I based my previous post on scrap parts from a dead forklift; the regulator and a "20 horse" LP carb. Plus hoses and cut-off, ETC.

To make it dual fuel and have performance? make up a "log" intake manifold and run the gas carb "wet" at a low idle setting, drive around on the propane carb for normal running, and use the gas carb as the "secondary" giving full throttle. When the Liquid Petroleum runs out, you're set to keep driving on gas (Petrol, sorry).
Or use 2 forklift LP carbs, and a tiny gas carb.

This is purely "bench racing" of course. There would be alot of fabricating and trouble shooting to make something safe and drivable, but a side car would help with hiding the LP tank.

 

All easier said than done.

I'm not so sure that there is a solution outside of Duel-Fuel Throttle-Body which would need a remoted solenoid to switch from one Fuel source to the other.

It's prety clear in my mind that neither Mikuni or Hitachi Constant Velocity Carbs are the platform for such a Mod.

You are going to have to see what's available and fabricate a Manifold.
The closest thing I can imagine using would be the Fuel Injection Manifolds that were standard on the Police Bikes.

 

We did our own conversion on a boat (5L V8 beast) and basically had to put a device like an oven hob on top of the carb and a valve to cut off fuel flow. My thinking was a similar ring type thing on the inlet of each carb and a valve to stop fuel flow to the carbs. Would just have to turn off fuel to carbs, and switch to gas (LPG) when the engine starts to splutter. I know that there was no kind of gas control valve connected to the throttle in any way on the boat conversion, and what I have reasearched leads me to believe that the suction from the engine will draw more gas from the bottle when engine speed is increased. Seems like a fairly simple job, just need all the right valve gear and a bottle, and a lot of time.