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Question about old OS Max .32 nitro engine?


Old 09-11-2017, 04:00 PM
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Default Question about old OS Max .32 nitro engine?

I recently dug out an old boat that I built from a kit more than 20 years ago (and never ran the thing). I'm fixing it up to give to my young son but of course the original instruction sheets for the engine are gone as is the instructions for the water cooling line routing.
My question involves the water line routing. It currently goes from the pickup tube on the tiller into the engine head and out the other side into the exhaust pressure nipple on the muffler. Is this the correct routing or should it just be routed over the side? What to do with the exhaust pressure nipple if my fuel tank is not pressurized?
I appreciate any help anyone can provide. Ultimately, I want to build a new gas boat from scratch with him but this old kit boat will get him started.
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Old 09-11-2017, 06:24 PM
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Your cooling lines should be routed so the water pickup goes to the head, and from the head to over the side. I have mine out through the transom on the old Graupner boat I have. The pressure fitting on the muffler should go to the vent on the fuel tank. Most engines benefit from using muffler pressure because they often have huge carbs and as such do not draw fuel very well on their own. Not to mention the engine won't lean out as hard towards the end of the tank if you manage to get it to draw fuel decently.
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