Hello Everyone.

I am new to the hobby and have tried to find the answer to this question. I have twin two-cycle engines and I would like to modify one of the engines to run in reverse. These are the mageneto style with spark plug. I would like to reverse one engine so that I will have counter rotating props. Is this possible? Check out the pictures and let me know what you think is my best option without converting them to glow type engines. Any help would be greatly appreciated. These engines are new but 15-20 years old and have never been used. They were made in Canada by a company called TMI or something like that. I think they are chainsaw engines that were converted to water cooled engines for a boat. I was told they are Quadra engines but I'm not sure. Any help would be greatly appreciated.

Yup, TMI engines (Trail Manufacturing Industries)from Canada.

Chainsaw engines rotate CW as viewed from PTO end, Our model boat engines nitro and gas rotate CCW .... So right away your having to source REVERSE rotation props to use then as they are without a rotation switch. Tough one there !!

As for the thousand dollar question on Reverse Rotation of one of them ?
First you would need to deal with flywheel and relationship of magnets to coils position so timing would be correct,
The ignition coil of the reversed engine also would require being flipped around 180* so it sees the magnets of flywheel pass underneath in the right dirrection.

** Next hurtle is starting, the start pawls on flywheel and rope starter won't work.
Also would need to confirm the clutch attachment to crankshaft and make sure it won't just unscrew it's self running reverse direction ? ( Been too many years ago and frankly just don't remember how they attach )

Sorry if sounding negative Not wanting to really. If you have the tools and skill to fabricate whats required it is very doable ... Just no easy fix tho sadly.

Best regards,
Scott

Thanks for the info,

As you can see from the pictures, the pull-starts have been removed. Starting will not be a problem because I actually have electric starts for each engine. These electric starters will run-start in either direction depending on how they are wired. No problem there. The props are not a problem, as I already have counter-rotating props for the boat. The only problem I have now is getting one engine to run in reverse. I did not consider the clutch. I thank you for bringing that to my attention. I believe I have a solution to resolve that issue. I don't have the tools or machine shop to modify the flywheel and ignition coil. I can have it done but I have not found anyone who actually knows what needs to be done. I have called several engine repair shops but none of them actually knew how to do it(make it run in reverse). They all could repair it if needed but making it work efficently in the opposite direction was another matter. I also talked with several hobby shops but still no answer. I don't mind having anything made if needed but I guess I need to be able to tell the machine shop exactly what I actually need. I am in PA and can travel to Jersey, Maryland,New York,Ohio or WV to have someone work on it but I have not been able to find anyone anywhere who can do this. LOL We have several places here that can machine any part that I need but I don't actually know what to get made. I am sure that I am not the first person to have this problem

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At least I hope I'm not

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LOL Any help that anyone could give or if anyone knows of where I could get it done would be a big help. If I can't get it done, I will have to keep both engines running in the same direction----which is not as good for performance and handling but mostly not as realistic as I would like

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Any Solutions would be greatly appreciated

Am I wrong for thinking that i could just flip the ignition coil 180 deg and start it in the other direction and all will be well? I understand that the flywheel my not move as much air but the engines are water cooled so I doubt that overheating will be much of a problem.

Ignition timing for reversed engine would go from firing BTDC stock to firing ATDC flipped around. The engines WOULD NOT run equally with such a timing difference.