Electric Start Flywheel

WillieS

Member
I know this really doesn't fit the performance nature of this forum - just hoping to catch some knowledge from someone that races that also plays with stock toys. Installing electric start on a Predator 69730 non Hemi 212. All the kits seem to use flywheels with the same +/- 5000 RPM limit as the stock flywheel. Does anyone know of a flywheel for electric start that has a higher RPM limit? Since I have a new engine already, along with the Stage 1 style parts for it, I don't want to dump it for the $300 Tillotson e-start engine, which has a lightened 9000 RPM flywheel. Any suggestions?
 
Just to warn you that flywheel is not rated for 9000rpms. It's a miscommunication between Ducar(The manufacturer of the 212E) and Tillotson. Tillotson describes the cast iron flywheel test procedure on their website "(up to 10,000 rpm for 10 seconds and 8,000 rpm for 30 seconds)," which is the same as any other cast iron flywheel. It was misinterpreted as a rating initially, and the distributors of that engine have refused to change their information because it's a hot selling point for that engine. Logically speaking, a factory flywheel that could turn 9000rpms especially electric start with lighting coils, would be an extremely good seller, yet it is not offered separately. We deal with this issue on a regular basis. ARC offers an electric start flywheel with a ring gear, but you lose the charging/lighting coils.
 
Thanks for the replies. Great info on the Tillotson flywheel situation - probably better than a stock e-start Predator one, but not "bulletproof". Weighing out cost to benefits to gain by switching to the Tillotson engine.

I guess it might help to explain what I have and what I'm doing. I'm very "laterally challenged" and I am building a trike to get around at racetracks and large open public areas. It will be used as a mobility vehicle, not as a "sport" vehicle, as in no wheelies, drifting, etc. The forward/reverse box and the differential axle I have are both rated at 10+/- HP, so making a lot of HP is pointless. I have a series 30 style Comet clone converter setup with the upgraded 7" driven unit. As for power - I already have a new (recoil start) non-Hemi Predator, along with a few odds and ends for a non-Hemi engine from past projects. My goal for the engine was to remove the governor parts inside the case, remove the oil sensor, new top plate, jet the carb, new air filter, new exhaust, probably a 2* advance key, 18lb springs - basically a "Stage 1" upgrade - and of course, the electric start, hopefully with charging coils.

Realistically the biggest question I have on this - there seems to be a lot of confusion about the RPM limits of a stock Predator flywheel. Seems like the consensus is that 5000 RPM is about the limit of the little hamsters running inside a stock flywheel - above that and they start tossing flip-flops through the fan cover. Again, realistically, 5000 RPM still needs a functioning governor. It's removal was more of a reliability issue, and not a deal breaker if it should stay. I wasn't looking as a governor being a top speed limiter as much as a broken part winging the RPM's to the moon scenario. At this point a lightened "stock" flywheel - AKA the Tillotson - would be a safer choice, but still not that much of an upgrade if the governor needs to be retained. Should the T/son need a governor retained for a "Stage 1" style engine?

So I'm probably at making the decision of cost VS benefits. I could probably buy a stock flywheel, starter, charging coils, etc. cheap and piece together the electric start function, since I will not be using the factory key box anyways. This is what I would do if I could find a "good" e-start/charging flywheel reasonably priced (for a non-Hemi). I can add a complete electric start kit to my Predator for +/- $100 and modify the engine as necessary. I can dump the Predator for $100 and buy a $210 Duromax e-start engine - again, needing engine mods. Then there's the dumping the Predator and buying the $300 Tillotson with the better flywheel, needing less mods.

So please, any thoughts or flaws in my logic? Not trying to make the budget entirely dictate the build, just trying to spend money wisely where it is NEEDED. Thanks for the input.
 
Leave the governor in add the mods .
Unless you want a different throttle control setup .
Governor failure would be a rare occurrence .
The simple solution is the e-start engine .
Either or deal the charging coils would be a benifit outweighing the governor in my opinion . If you can get a setup for the predator that would be fine .
Although constant loss system may start it for a full day or more .
Depending on battery size .
Recoil start as back up .
 
With guides and pulleys you may be able to extend the rope /pull handle to a more convenient place as a secondary start method .
 
Build an adjustable throttle stop and skip the governor. I have a 'box stock' 212 that I race in a class with a 5850 rpm limit rule, no governor required. I kept the stock throttle plate and use the original throttle stop to stay at the rpm limit. And remember, 5000 rpm while free revving is a lot more rpms than you will be actually driving with.
 
Thanks for the replies. Probably going to dump the Predator and buy a Tillotson with the electric start already installed.

There are pros and cons to both methods of limiting RPM.

Using the governor - there are more moving parts to wear, fail, bind, etc. On the plus side, you see full throttle from idle, and the throttle is only ramped back to maintain set RPM. All mods are external - no removal of engine side cover necessary, In fairness to this statement, I probably will remove the low oil sensor, which requires the side cover to be removed anyways.

Deleting the governor - Less parts to wear, break, bind, etc. To truly delete the governor, you need to remove the engine side cover, which to some may be intimidating. The main con to using the throttle stop method in setting max RPM is it does not allow true full throttle from idle, since you are controlling max airflow by limiting the throttle blades max opening at all times. This can limit max RPM under load. In some cases to limit an engine to 5000RPM at free rev, you may only see the throttle blades open 3/4 of the way. While this may not be an issue in a racing application where you only need power off idle once in a race, it is something to consider in other applications.

With all that said, probably leaning towards keeping the governor and turning it up to a "safe" max RPM. I think for my needs this will work just fine. Again - thanks for the replies and input. Willie
 
With guides and pulleys you may be able to extend the rope /pull handle to a more convenient place as a secondary start method .
Rotating the pull start gets it to a useable position for starting plan "B". I'm just always leery of starting something I'm not sitting on, although in this case the forward/reverse gearbox has a neutral in it - as long as I remember to put it there to start LOL
 
Are you using a motorcycle type throttle or a thumb type , like on a snow mobile ? The latter is what some of the racing mowers use .
 
Are you using a motorcycle type throttle or a thumb type , like on a snow mobile ? The latter is what some of the racing mowers use .
While I would prefer a thumb throttle, the throttle housing assy is a twist style. Any reason you ask, or just curious? The right side of the handlebar will have the throttle/switch assembly, and a brake lever/master cylinder.

The fuel tank will be remote mounted, so I can run any top plate I need.

I would like to find a thumb throttle that had the on/off switch, start button, and light switch all in one like the twist style I have picked out, but I have not found one yet.
 
While I would prefer a thumb throttle, the throttle housing assy is a twist style. Any reason you ask, or just curious? The right side of the handlebar will have the throttle/switch assembly, and a brake lever/master cylinder.

The fuel tank will be remote mounted, so I can run any top plate I need.

I would like to find a thumb throttle that had the on/off switch, start button, and light switch all in one like the twist style I have picked out, but I have not found one yet.
Curious . It you get a thumb type from a snow mobile , make sure it doesn't have a warmer on it , they tend to get pretty hot without a glove , lol
 
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