Tomos 5 HP motor questions...

[pikeslayer23]

My 5 hp Tomos outboard keeps shearing the shear pin. Any thoughts? I replaced it once, and the next time I ran the motor it sheared again.<br /><br />It's an air cooled motor.<br /><br />I have been running this motor using a 50:1 mixture of 2 cycle oil and gas. Should I consider using an oil specifically for air cooled motors? The guy at the local marina told me to go with the 50:1 2 cycle mixture.<br /><br />The motor is mint, looks like it was never used, so I picked it up for $50. The thing starts like a champ and runs beautifully in neutral, it just doesn't drive becuase that shear pin keeps shearing.<br /><br />Where could I get a manual for a Yugoslavian made Tomos motor?<br /><br />Any thoughts or advice would be greatly appreciated.

 

[Paul Moir]

Re: Tomos 5 HP motor questions...

The only place I know of that deals with Tomos is Bosunsmate in the UK. But this quote about the 4.8hp from that site might answer your question:<br />

Eats the original brass shear pins for breakfast - use stainless. 18kg.

Since it's an air cooled outboard, use air cooled engine oil. Generally speaking, air cooled engines use more oil than water cooled ones, so mix rich until you can find out what the mix is supposed to be. Worst that will happen is you foul a plug.

 

[pikeslayer23]

Re: Tomos 5 HP motor questions...

Paul, U da man! I'll try a stainless pin. I wonder why that is, that they eat up the brass one's for breakfast?<br /><br />I'm gonna start going w/ the air cooled engine oil too. Any advice on the mixture ratio? How does one determine the correct mixture, what are you looking for/listening for to help find the right mixture? I don't quite understand, if I'm mixing too rich, what will I notice... and then what should I notice upon finding the correct mixture?<br /><br />Sorry, I need the Boat Repair for Dummies instructions. This motor I got is a runner, I can tell that much, it's super clean. I just wanna maintain it and operate it the best I can.<br /><br />Thanks again!

 

[Paul Moir]

Re: Tomos 5 HP motor questions...

I'm afraid I can't find what the mixture ratio is supposed to be. The way I see it though, if you have the ratio too heavy with oil, you'll end up fouling your spark plug. Basically, the firing end gets covered with carbon deposits, which shorts the plug out. You can pull the spark plug and have a look if you suspect they are forming. Or are just curious.<br />If you use too little oil for the engine, major internal damage is the result. So it's a good idea to err on the side of caution until you figure out what it should be. Perhaps the folks at Bosunsmate can help.<br />Until then, I would shoot for 32:1, or perhaps a very rich 24:1. 32:1 should be pretty safe though.<br /><br />Hope this helps!

 

[pikeslayer23]

Re: Tomos 5 HP motor questions...

Thanks again. You have been super helpful!<br /><br />best regards,

 

[pikeslayer23]

Re: Tomos 5 HP motor questions...

One more question. I want to switch from TC-W3 to air cooled engine oil. A fact sheet I read by Penzoil, for their 2 cycle air cooled engine oil, says to take special precautions not to commingle the two different types of oil. There's got to be left-over TC-W3 oil in the engine, so how do I make sure the TC-W3 and air cooled engine oil do not commingle? Any suggestions? Or do I just need to clean the old mixture of gas and TC-W3 out of the gas tank real good before starting to use the air cooled engine oil? Thanks for any advice.

 

[Paul Moir]

Re: Tomos 5 HP motor questions...

This isn't really good advice since I really don't know about the possible problems with switching from TCW3 to TC oil, but to be on the safe side I would probably just run the engine at low rpms for an hour with the new oil to clear all the old oil out.<br />That's just an idea though. Perhaps someone will be by with some more useful and practical advice.

 

[sea king 5]

Re: Tomos 5 HP motor questions...

dued: Black plug (to much oil) and more smoke<br /> Brown plug (correct mix) so so smoke<br /> White plug aint gonna matter (new engine)<br /> I don't know if Amsoil makes a 2 stroke oil<br /> for boats but in a wead eater I've mixed 100/1 and no smoke,and most of all,(brown plug)<br />If you can find it,it's worth every $

 

[pikeslayer23]

Re: Tomos 5 HP motor questions...

Thanks for all of your help. Now I just need to locate the spark plugs on this motor. I have looked for them before and they are not visibly apparent. I honestly do not know where they are located on this motor. There are no visible spark plug wires or boots. I hesitate to tear into this motor without a manual, but you would think the spark plugs would be easy to get at. Thanks for all the advice!

 

[pikeslayer23]

Re: Tomos 5 HP motor questions...

OK, I tried to find the spark plugs on this motor, and I'm not sure this motor has spark plugs. It has pull starting and electric start, although I do not have the cord and wiring to utilize the electric start.<br /><br />Is it possible that this motor does not have spark plugs?

 

[sea king 5]

Re: Tomos 5 HP motor questions...

I have never heard of a engine that doesn't have plugs, I understand that you don't want to get your hands dirty without a manual, if you posted the # s on the board, you may find a manual! If not, it was broken when you got into it! ask a bunch of questions from alott of fokes, and figure out what your gonna do.<br />The only dumb question, is the one not asked.