Another vote for turbo-charging I have never use propane but I think for low maint a T-charger is the way to go. I have the Hypermax kit on my M/H the only change I plan to make is getting some ducting to the airfilter for cooler air I am not impressed with the placement of the filter sitting right about center of the motor EGT's get a littel hot but nothing that backing out of the throttel won't correct. But let me tell ya the T-charger flattened out the hills its pretty fun to hang at 70 to 75 up-hill down-hill everywhere.....Bill
Turbo is the way to go, I vote for ATS. Will give you better performance. Do not forget to modify your intake More Air In - More Exhaust Out. Put in a decent set of guages PYRO first before you turn up the pump.
That is the sweetest whine you will ever hear.
And the three inch downpipe and exhaust is also a must.
After you run that for a while, when you want more power, then you can add the propane and get a real kick.
The NA motor just can not get enough air to really turn the fuel up and run propane to get a good kick.
If you have a turbo put it make sure the shop knows how to mod your IP and try to take it to a turbo/turbine nerd. They do the best work and can usualy be found running a small shop in an industrial area near an airport. It will be more than a regular turbo but it will kick harder.
If you do propane the upfront cost will be much less like $300-800 even less if you get used parts (used tanks and regulators are easy to come by). Compaired to turbo which start at $1000. However, you will have to build on a liquid propane tank and buy propane which is $1.80-2.50 around here. So, over the long hall (years/thousands of miles) propane will outprice a turbo unless you abuse the turbo.
My personal conclusion; if you got the $ get a turbo... i'll be running propane.
I am going to go against what everyone else is saying.
how much do you want to spend. I built a propane kit for less than $200. It added so much fuel mileage that it doesn't cost anymore to run than running straight diesel. Also it adds more power than the turbo. I have had turboed trucks and non turboed trucks with propane. Propane adds more power. Now I have a truck with propane and a turbo. Real sweet.
I like the turbo idea. You dont have to keep refilling the tankwith propane and it will last a long time. Go thru different altitudes with propane and adjusting is necessary, the turbo doesnt need constant attention. ATS is the system that Ford used on their factory system in 93-94. Its your scooter and your wallet. Enjoy the ride either way.