TDC (Top Dead Center Timing) for Trojan Tornado 75 outboard (Australian)

[Monte NZ]

Help again please.
This time I need assistance in establishing the above.
I have found the measurement on the Trojan Mini Motor Cycle sight in the UK, but unfortunately the page with the details is very fuzzy and can’t be read
and I was wondering if one of our Australian members could please advise me. I have established that these 75cc motors were virtually all aimed at the Australian market and were used on outboards and lawnmowers plus other machinery. It was interesting to learn from the Trojan Museum in Croydon that they recently bought a Tornado 75 off Ebay to complete their display.

Thanks in advance.
MonteNZ

[garry-in-michigan]

Establishing top dead center in an outboard hs easy if the spark plug is over the top of the piston. First you need a place on the block under the edge of the flywheel to use as a reference. If nothing stands out, make a mark with a cold chizle. Next thread a bolt into the spark plug hole far enough to keep the motor from turning over. (A hacksaw cut across the bolt will relieve compression – or a pass with a Dermal cut off wheel.) Turn the flywheel in one direction until it stops. Make a mark on the flywheel above your reference mark with a felt tip pen. Turn the flywheel backwards until it stops. Make another mark. Top dead center is between these two marks, equidistant from each. . . . 😀

Garry

[Monte NZ]

Thanks very much Garry for your help …. much appreciated!

MonteNZ

[ausf233]

G’day MonteNZ,

The Trojan engine fitted to the Seacraft Tornado is not too dissimilar to may of small engines of that era. The spark plug enters at the center of the head, therefore finding TDC is as simple as removing the spark plug, holding a pencil or similar against the top of the piston and rotating the crank until the piston is in its outermost position. I say outermost only because the head is arranged horizontally. All other tips that Garry has provided are valid and should help you with the timing.

Be aware however that the Trojan engine fitted to the tornado is not the same as the Trojan Mini-motor as used on Cycles. The Tornado has a 75cc engine, whereas the capacity of the Mini-motor is only 49cc. This motor also has a slightly different fuel and exhaust arrangement, hence the timing information (even if clear) may not have been transferable to the Tornado outboard anyway.

Just to close off, for those who have not yet seen a Seacraft Tornado, following pics are of the latest model with underwater exhaust. As said by MonteNZ, they were originally built by Seacraft in the late 50’s and early 60’s. Seacraft was located in Mordialloc, Victoria, Australia which is approx. 2 mile from where I currently live.

Seacraft history here: http://www.seacraftskiboats.com/index.html

Regards,
Spiro

[Monte NZ]

Hi AusF233 (Spiro)
Thanks very much "neighbour" ha ha,for your very interesting information. You will be interested to know that I have just discovered more specification details of the Tornado 75 on a website dealing with the 49cc bike motor. It mentions the Trojan Tornado 75cc and says that the timing is 29 deg ( 1/8 inch) for TDC. Thanks for the excellent photos. How old is the motor.?…..it looks brand new! My one has had a pretty hard time. I am getting a good spark and the carburetor has come up well. The bore has been honed and my next job is to file the rings ends to fit round the locator pins. Fortunately the gear box is full of grease with no rusting gears. I would love to put up photos of the motor, but unfortunately at this stage I don’t know how. A friend of mine has offered to show me, but currently he’s very busy.

Kind regards
MonteNZ

[ausf233]

G’day MonteNZ,

If you could post a link to the website or websites you are sourcing your info from, it would be much appreciated.

My Tornado is a well maintained original, owned by one family (until I bought it) since new.

They repainted the cowl and tank (poorly) about 10 years ago, and re-fixed the makers plate with self tapping screws instead of pop-rivets. All that will be corrected soon.

It usually starts on the first or second pull and runs very smoothly.

I also have an original mini-motor ready to fit to any cycle in much the same condition.

As for posting photos, I suggest you set up an account at photobucket.com. Upload your photos there and then simply link to your posts by copying and pasting the IMG code. Very simple to do, however if you need help let me know and I’ll put together a step by step guide for you.

Regards,
Spiro

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