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ZacLamb

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After finishing the aprilia sxv project, it's time to start another one. I saw a thread about 2-stroke fuel injection, so I figured i'd let the cat out of the bag. We've been working on adapting mechanical fuel injection for 2-strokes for about a month now. Still sorting out fuel pump mounting and drive ratio, as well as making an intake manifold. The throttle body is 50mm and should work on many engines with just the change of a injector nozzle. We plan to test it on a 125. I have no idea how well it will work, but it's no fun to only talk about it and not try it.

Pics:
http://i923.photobucket.com/albums/...e-e172-430c-b258-d75bb4d362e2_zpsowrlky9y.jpg
http://i923.photobucket.com/albums/...injection/IMG_20150810_161253_zpsv29v3rta.jpg
http://i923.photobucket.com/albums/...injection/IMG_20150810_161243_zpsoyzpm3c1.jpg

Side-by-side comparison to buller duals:
http://i923.photobucket.com/albums/...injection/IMG_20150810_160930_zpsr5pxdx6a.jpg
 
Tried it on a standup jetski with not to much luck, hope yours goes better that was the same problem I had with the drive ratio.
 
mrd? That's what this is, I just chopped it in half to use it on a single cylinder. A lot of the ski guys complain about them, but others love them.
 
Good to see that you are going mechanical pump.
Back in the '70s I ran a 440 Brut snowmobile in USSA Mods, that I waisted $$ on a SSS Fuel injection set-up for.
It used damn pulse pumps, and it was almost impossible to keep the mixture correct on it as the weather conditions changed during race day.
 
I think it was in 1991 when a guy by the name of Mike Hoffmeister ran fuel injection on a Komet K78. He did win the Russell Truitt Memorial that year. That's about all I can Remember about it. Have no idea where Mike is at now.
 
Zac, who makes the pump and how much pressure dose it make. trying to make an injection system for a 250 cc kawy using a kein carb for a throttle body to make it look stock. I have it all made out in my mind.
 
The pump I have is no longer being made. It's a very small twin gear pump. Maximum pressure will be controlled my a pop-off valve, many different pressures to choose from. The system i am building will work much like a hilborn system. Aeromotive, waterman, and a few others make nice belt driven fuel pumps. But it's difficult to find a small one, i'm currently looking for good options.
 
been thinking of using the kick starter drive to use for the pump drive. We usalley pull all the kick starter and hard ware out and plug hole in case. Just make spacers for shaft,pull the spring out and go from there.
 
Can you take a belt driven pump and make an adapter plate and put an r/c motor on it? Variable speed with a servo tester, or if constant speed is required gear it or control voltage, accordingly. Just a thought. Cool project.
 
The kicker runs off the crank through gears. I looked on watermans sight and found one used in Nascar a cable to drive it. My friend said have you ever turned one by hand they turn hard. I told him the one we had on our sprint car didnt turn hard it was built by kinsler.
 
Ksfastman said:
Did anything come together on this? I know it's a very old post, but curious whether it ever got finished and ran.
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Nope. I always had a lot of projects going and this one was never finished. Mechanical fuel pumps were pricey and I was on a grad student budget at the time. I did eventually build an EFI kit for an aixro. Which operates very similarly to a 2-stroke (one explosion per crank revolution). Considering that the MX 250 2-strokes come with a crank position sensor, EFI would be the way to go. For smaller 2-strokes you might as well take advantage of the weight savings and stick with carbs.

I still hop on here every once in a while to see if anyone is building anything interesting. Good to see some one is still interested in innovative ideas. But if you want to win, just buy what every one else is running. I liked to build things, so winning didn't happen. zac
 
Do you still have any of the MRD stuff? We used to race PWC's and had a few MRD systems. The pump is a cute lil' rascal lol.
 
Ksfastman said:
Do you still have any of the MRD stuff? We used to race PWC's and had a few MRD systems. The pump is a cute lil' rascal lol.
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I don't. Only think karting related I still have is this expensive door stop:
PXL_20210925_222156624.jpg
 
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