Hi DAZ,
Could you post some photos As we all would like to see it.

Martin555.

Thank you all once again, i've sent the muffler off to a mate of mine to weld a pipe off of the muffler and the leather strap works great ( i've spent most of the day creating an electric motor start but the leather works much better and doesnt detract from the boats orginality); although my leather belt is now just a buckle.
I'm going to try and find a boat club around here, but with current lockdown restrictions i'm unsure if that'll be all that easy..
I've a few cosmetic bits to finish whilst im waiting on the exhaust / muffler to be done, but I am hoping to take it on our lake beginning of next week..
Cheers
Daz

Hi Daz, here is the tank pressure set-up as mentioned by Martin. You would need to buy a starter such as a Sullivan, and find a suitable small V belt (around 6mm wide ) from model shop or sewing machine specialists (or via boat racing club source). You will need one which is long enough to clear the deck of the boat by around 3" so the starter can be used horizontally (as in Martins drawing)

Years ago we used to use a square leather boot lace to start boat motors. You don't wind the cord round the flywheel,- just loop it under the flywheel and holding the boat down firmly (a helper is good for this) using both hands, apply tension to the cord and pull up (to make the flywheel move anti clockwise (from the front of the motor), - slacken the tension, bring cord back and repeat ( sort of zip the cord back and forth quickly, - tension pull,-relax pull back etc).

You will need to prime the motor by hand (finger over carb while turning anti clockwise by hand till you see fuel coming down the line and into the carb . If motor locks, it's flooded,- remove glow plug, spin motor with cord or starter to get rid of excess fuel, replace plug (do not overtighten plugs,- firm is fine) and re-try. Experience will get you sorted. As martin suggested, a good idea would be to go to your local boat racing club for direct advice.

Make sure you start on very low throttle to avoid over revving the motor and get it in the water as quickly as possible to avoid overheating. Hope this gives you a bit more of an idea.
See guy using cord starting in beginning of vid. Pic of green boat is one I built around 1977 and has the same O.S Max .40 as yours. Went quite well and very reliable.
JB

Hi DAS,

I have tried looking for the start up method on utube but at the moment i an unable to find anything.

It is like a large "O" ring that goes between two pulleys
One on a starter motor and one in the prop shaft (see quick sketch)

I have seen a nipple or tube brazed to the silencer part of the exhaust system.
As i have mentioned i don't know a lot about this type os system but the best guys to help you with this would be the guys that run the fast speed boats.

Martin555.

Morning Martin, i presume that the belt and electric motor doesnt disengage once the engines fired up? I can certainly build something although space inside the boat is at a premium now. Regards the fuel tank, it seems to keep pressure, the orange tube off of the top of the tank id have thought was only a breather tube?
I'll have a look through the instructions that i was given for the 30. Im just wondering as the exhaust system is a custom built copper. Unsure where i would put the breather tube on to the exhaust... i'll do some more reading..
Thankyou everyone for all the assistance, it's greatly appreciated.
Cheers Daz

Hi DAZ,
The piping that goes back to the fuel tank from the exhaust is to pressurise the fuel system.

As for a Firewall i don't think it should get that hot to need one, but there is no harm i fitting one just for piece of mind.

I have seen a system for starting that uses a separate battery powered motor and a belt that fits around the shaft pulley.

Martin555.

Morning, thanks for this, yes it is water cooled. The pull start is a bit of a nightmare, there is no built in pull start return so im using a piece of cord and having to keep rewinding it, i agree it is very tempremental, but im getting there slowly.
One question. Im thinking of putting a fireboard between engine and fuel tank. There wasnt one when i was given it but im unsure as to the amount of heat that it will produce, the exhaust is something that the old bloke created, im unsure what was meant by a pipe going back into fuel tank? Ive attached a couple of pictures..
Lastly im a director for a social enterprise and we have a boating lake and fishing lake, im looking to create an rc club, once ive set it up would it be ok to promote the club on here?
Many thanks Daz

Many thanks

Re, I have been given an old boat, it has an OS MAX 40rc

Hi Daz, here's a manual from a Max .30 I have, (same info as the .40) You can buy the fuel from most model shops ready made . Don't use high nitro fuels as these motors should have no more than 5% max for contest use as they are not built for too much nitro. They are a ringed motor (Dykes ring) not ABS and you will cook it on too much nitro.

If you can find quality first pressing caster oil for model use, that's the best (although messy) as it lubricates well at high temps. Nitro use causes rust in the engine (although the .40 Max only has bushes not bearings so is not affected as much) and requires using an after run oil to prevent this, - (caster just goes gooey with long time storage.)

Don't think you will find any caster fuel these days though as it is mostly synthetic oils now. Fuel should be as close to the proportions shown when buying from the model shop, (minimum nitro or none, as these don't need nitro)
The methanol and oil are pre-mixed (do not use petrol and 2 stroke oil,- it wont run). You'll need a glow lead with a 1.5-2v battery for starting (depending on plug specs) Use an O.S No 7 plug (watch the lengths of other plugs re piston clearance, temp etc)
Hope this helps.
JB

Just a suggestion.
Contact model car web site as i think these engine are used in them.
I have spoken to my son who was into fuel driven engines
1 the fuel you buy has the lubricant mixed in eg nitro 16, nitro 20, etc. the higher the number the more performance. However too high will burn out the engine.
2 He assumes the starting is by pull cord.
3 He also asked if the engine is water cooled, the engine needs cooling, cars just use airflow.
4 The current engine use a pipe from the exhaust to the fuel tank as part of the fuel supply. if not the engine may use petrol oil mix like two stroke mixture.
5 in a down side these engines can be tempermental . Patience required.

If you wish more information please post some photos of the engine setup.
He says a good model shop should give you good advice.

Hi, many thanks for this, i've got a steep learning curve.
I'll have a play and read up on the link.
I'm sure i'll be in touch ( quite often) asking for help.
Thanks again
Daz

Some of the glow fuel had a 20/25% castor oil mix in them.

Have a look at the test from the 1973 Radio Modeller.

Fred

Hi Daz,
I have very limited experience with these types of motors but i think the oil is already mixed in the fuel.

Hopefully other members will be able to help you more.

Martin555.