I ended up going with the Mishimoto MMFAN-CNTL-U

https://www.mishimoto.com/adjustable-fa ... r-kit.html

The last few weeks have been pretty busy for me but hoping to get back to this project soon.

It's gonna be one kick ass machine when you get done with it! Looks fantastic

You do incredible work. The attention to detail is amazing.

Finally got back into this project. Got it sitting on all 4’s and have been making progress towards its ability to run and ride. I have rebuilt the axles and assembled the front and rear suspension. I got a used set of fox shocks on it front and rear. Although they look pretty rough, they seem to be in decent shape and I’ll run them for the time being, but I will send them out to get rebuilt at some point. I put some new front tires on a set of champion bead locks I had kicking around. I built a heat shield for the starter motor (( Internal Combustion Engine ? )) and trimmed the steering column to fit around the power steering unit. I also made a mount for the power steering control module. I got the bungs welded into the exhaust manifold as well.

Throttle cable and choke cable have been sent out to have custom cables made with splitters to work with the lectron carburetors. While I wait for the cables to return, My plan is to get the new brake hoses run and bleed and start to dig into the electrical.

Going to put some reflective heat tape on the heat shield.







Put the bung/ sensor in for the fan controller.

Dang been a long time! Good luck

Thank you! It has been a long time and life had gotten busy for me. I have a new job now and a little more time to work on my hobbies. Looking forward to getting some seat time here soon.

Curtis, great to see you're still in it. Build looks great.

Thank you!

awesome work on this! where do you ride in RI? who is making the cables? thanks

I am having Barnett make the cables for me. I have a few friends with farms here that I will ride at with them. I have a camp in NH and that is where I do most of my riding.

Two other things I would like to note that might help others with this swap.

1. The rotax 600/700/800 swaps do NOT use the stock pilot belt. Need to use a Dayco HP2020 belt.

2. Where the rotax Engine mount attaches to the gear box, the 2 lower bolts have clearance issues with the brake rotor. I was able to remedy this by grinding the lip off the end of the bolts. Also, install the top bolt in the reverse direction as the lower bolts, this makes it easy to remove without pulling the driven clutch.

Got confirmation on my cables from Barnett today. Should have them the end of next week. Here are the drawings they made me if others might find use of them. The Lectron carbs have a specific choke plunger that made things take a bit longer. Lectron was able to sell me the parts needed for Barnett to complete the choke cable as I wanted it. I felt they were a reasonable price, $75 per cable.

Got my new cables back from Barnett and got them installed over the weekend. They fit great. I cut up a FL350 steering colum and made a bracket for the ignition and choke cable.

Finish up a lot of the wiring. All factory items are working, koso gauge is energized, also the power steering. I still have to finish up the Engine electrical and the radiator fan controller. Some of the issues I ran into are:

1. I did not have the stock ignition and I couldn’t find a replacement ignition that had a dual contact closure in the on position like the oem pilot has. To fix this I used the one contact closure to pull in a relay and energize the second circuit.

2. The KOSO egt, temperature wires are not long enough. I got one egt extension cable from KOSO but I do not have a solution for the second yet. I could cut into the factory harness and extend it, not sure if this would affect the reading? Same with the liquid temp?

Made a bracket for the mikuni fuel pump part number DF52-176 and got a new K&N air filter part number RU-148.

Small update on my last post. With the help from a gentleman on the Facebook page I was able to find the correct ignition. It is an ignition switch from a Honda fourtrax 300 oem part number 35100-HM5-671. This ignition had a dual contact closure when the ignition is in the ON position. Note: I had already purchased an aftermarket replacement for this ignition part number that did not work properly. Only the oem replacement worked as required.

After a bit of communication with Koso, they lead me to a vendor for the egt extension wires. Exhaust Gas Technologies

https://www.exhaustgas.com/DeptSelect.a ... &BasketID=

They are making me the extension cables I need so that I don’t have to cut up the factory harness and void all the warranty’s. Should have them the end of next week.

I will be finishing up the Engine electrical this weekend.

You're Welcome

Looking forward to see this finished.

Lanix, you’re the man!

I’m finally feeling like I got this project in the home stretch.

I have got a lot done the last few weeks. I got just about everything wired up. Made a few brackets to hold and mount electronics. Almost ready for coolant and fuel.

My intent is to have everything work as the factory pilot came. There are 2 things that I will finish at a later date are the steering yoke fuel level alarm light and the coolant high temperature alarm light. These will both need bungs welded into the gas tank and radiator. My koso monitors the coolant temp and will also alarm on high temperature but I’ll have to manually check the fuel level for now

My plan is to post wiring diagrams for the rotax Engine and the accessories I am using. This will hopefully help others with where to tie into the factory wire harness and why I did it the way I did. I was going to start posting them but I figured I will wait until it is running and proven. Once proven, I would like to clean up the factory harness and remove plugs and secure wire no longer in use.

This weekend I worked on getting the brake lines bleed. Adjusted the front shoes and everything feels good and tight.

Bracket for rotax electronics and cooling fan controller/relay.


Rotax key mount & will add an override switch for cooling fan.


Steering yoke with koso

Got the FL600 running but not without a few setbacks.

The first one being that in the process of getting it running I destroyed my starter.
In a combination of the powerbloc and ring gear, the ring gear is 3/16” closer to the Engine than the oem clutch & ring gear. This caused the starter to rubbing against the ring gear until it finally wore right through. Long term I would like to find a solution to this issue but for now I reinstalled the oem clutch.







Second, being a bit discouraged about the starter issue, when I left my shop I forgot to turn off the fuel and it remained open for a few days. Came back to my shop to discover the cylinders filled with fuel. Not sure how that is happening as the Engine was off and fuel pump is using a pulse line. Possibly getting siphoned be because the pump and carbs are below the tank?!? I have been starting the Engine with the fuel valve off and Turing it on once it’s running. Shut it right back off when I shut down the Engine and issue stopped. Still waiting a long term solution and open to any suggestions.

Next I was battling a few coolant leaks. With everything installed I had to reroute a few of the lines and get more hose. Over 20 hose clamps and several 90deg fittings later the coolant lines were in. I still have a little seepage at the flange in the Engine head but have ordered a new gasket which should arrive soon.

Lastly, one of my EGT sensors doesn’t seem to be working so I got to dig into that a bit.

All in all it runs great and sounds awesome. Hopefully I’ll be able to get it out this weekend and dial in these lectron carbs.

I'm thinking spring and ball check valve right now.
When the pulse pump starts pumping it will overcome the light spring pressure.
This unit would have to be made large so that you don't starve the carbs.
You could probably put it in the feed from tank line as well but if the head pressure is to great it might overcome the spring.

Another option might be an ASCO valve but I don't know if they make them for gasoline.
We had these all over the place in all of the various factories I've worked in.
But I would pass on this one as I remember these being pricey depending on what they were controlling.

My first choice would be a homemade spring and ball check valve (adapted pcv valve ??).
CO

For the starter, You might be able to put a shim underneath the spring on the Bendix, that way it can't fly out as far.

For the fuel issue, you could relocate the fuel pump above the tank. But that might be more trouble than it is worth.

Yeah ASCO use to be of the highest quality, longest life in the industry when I worked with ASCO valves in an industrial production environment back in the 80's, super high cycle life. The only thing I seen ever go bad with them is the coils would fail in a high heat environment AKA Aluminum die casing facility they were used on the aluminum casting machines where it does not get much hotter.

Contact ASCO see what they have for your intended application.

Thanks you for the suggestions guys. I will reach out to ASCO and see if they have a valve that will work with fuel. My understanding is this is a 12v valve that would open/close with the ignition?

I had thought about moving the fuel pump as well but I am not convinced it will resolve the issue. The pump is currently below the carbs and it has its still pulling through the pump up to the carbs.

I found this repair kit online so I am going to try rebuilding my failed starter as it is essentially brand new. In that process I will see about shimming it to restrict the bendix throw.

https://a.co/d/aTp0mKw

I would not run a fuel pump or the ASCO load through the ignition switch I would add a relay, find a relay that is water tight.
Make sure the ASCO valve is 12 volts DC. The relay is extra work but finding a replacement ignition switch... Let me know the advertised rated amp draw of the ASCO valve coil it might a insignificant draw on the switch?

Back in my ASCO days I never paid attention to the coil amp draws as it was not really an issue.

Thank you. I will ask them for that information as well. I have a few waterproof relays on hand.

I got both EGT sensors working today, think I fixed the coolant leak, and started a bracket for a coolant catch tank.

Finally got it drivable. Thing rips! Just got to fine tune the carbs now and get some plastics on it.

How do I post videos on here?