Product Review Article...

A look at this neat tuning accessory for Zenoah engines, by M-Boat USA...

Here is an interesting product from M-Boat. It is an adjustable timing plate for Zenoah engines. What this plate does is allow for fast and simple adjustments of the ignition timing by relocating the pickup coil in relation to the engine flywheel. Once the plate is installed on your engine, you can vary the timing advance from stock to 10 degrees advance by simply loosening two allen screws! Although many might argue that the stock timing on Zenoah engines is optimal, this adjustable timing plate will at least give boaters an easy way of experimenting with different timings without any special tools.

Here you see what is included in the kit:

Installation of the kit is relatively simple. There is however one part that might be a little scary when you first consider it...I know I was a little weary of doing it at first. That is the part about cutting away part of the engine case! As you can see in the pictures the back portion of the engine case that supports the pickup coil must be removed from the engine in order to install the timing plate. To do this you must of course remove the pull starter, flywheel and pickup coil from the engine. One could completely disassemble the engine and cut the case on a bandsaw and possibly finish it off on a mill or sander to get a perfect finish, but the finish here is not really important. The important part is that you cut the case at the proper location (28 mm from the gasket face) and that you do it as straight as possible. I wanted to do this as simply as possible to see if someone with minimal engine knowledge could do it without taking the engine apart. I followed the suggestion from M-Boat that I could simply use a hacksaw to do it. So I marked the case all the way around (at 28 mm) and hacked away! It actually worked out quite well and was easy to do.

With the cutting of the case done, it's time to mount the main plate to the engine using the screws and spacers supplied. Then you mount the adjustable plate to the main plate and mount the pickup coil to the latter.

Finish by re-installing the flywheel, front engine mount and pull starter. There are spacers and screws supplied in the kit for installing the stock engine back plate (or your engine mount). The engine in this article is equiped with M-Boat mounts.

Here are a few pictures of what the completed installation looks like. Now you can set the timing to wherever you like and start testing!

I have done some testing on the test bench and have noticed some improvements in top RPM with advanced timing on the subject engine. I then continued with some testing on an inertia dyno to see how the overall power of the engine was affected. I did back to back testing using the same engine. The pipe and carburetor settings remained the same throughout the testing. The only factor that changed was the ignition timing which was easilly and quickly adjusted between pulls. The results were very promissing!

In light of the results I got from testing on the dyno, I feel that experimenting with timing advance on Zehoah engines is worth it. I will be doing more testing in an actual boat come spring time and the M-Boat adjustable timing plate will make it easy!

Happy tuning!

Contact Information:

M-Boat USA

Website: http://www.mboatusa.com

Price of Timing Plate at the time of this writing: $70.00 USD

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