Tanaka 3HP - Tune Up

[osubg1]

I have a Tanaka 3.0 H.P. Model 298.586191 - Not sure the year

I bought it 3 years ago, almost new condition. I took it on a trip without any maintenance (bought and used that weekend). I used it for one trip as a backup motor/trolling motor on a 16 foot sailboat. The only issues I had were it cut out at 3/4 - full throttle - that seems like a common thing based on this forum. They are not meant to be run at high rpms for long periods?

I'm taking it out in 2 weeks. This time I thought I'd give it a once over. So far I took apart the carb and petcock, cleaned it all out. They looked perfect, didn't see any gunk or anything. Gas tank looks fine, some residual oil from emptying it last time, but nothing bad.

Questions;
1. I looked up the parts diagram for the carb. It looks like there's a high altitude kit - is there any way to see if mine is already set up for high altitude or not? I use this motor at 8,000 feet in Colorado. It seemed to run ok last time minus the full throttle issues. But that could have been the jetting, now that I see this kit. Any one have any ideas? It looks like the kit is $31 - Carburetor Kit [39904] - $31.39 at eReplacementParts.com . I did buy it from a guy at this altitude, maybe he had already done that? It did run well, minus cutting out at higher power.
2. Should I change the lower unit oil?
3. Spark plug was oily... I'll get a new one anyway. Still could be a fuel jetting issue?
4. I noticed this last time I took it out also - there was oil spattering around the back of my boat. The exhaust gasket seemed to be leaking a little oil. There are oil spots all over the muffler (ridged flat cast metal plate). It also looks like the muffler gasket is no longer made. Is there a liquid gasket that would work for this? Assuming that's where the spattering is from?
5. I'm going to change the fuel lines from the tank to the carb. My motorcycle fuel line is too big - is there a good place to find the thinner stuff? 4.5mm ID is what the parts diagrams say. I'm looking for the clear.

Lots of questions I know, but maybe someone can help me out here.

Thanks

 

[osubg1]

Re: Tanaka 3HP - Tune Up

I won't be able to get the high altitude in time for the trip - but I might get one to put in there for later.

Here's another question - have you seen this before? I think the previous owner adjusted the angle of the prop/bottom bracket.

Take a look? Is this something people do for odd mounting positions? I need to fix this, I can take a look at the parts diagrams and get it, but has anyone seen this before?

 

[osubg1]

Re: Tanaka 3HP - Tune Up

I appreciate all the responses!!! :facepalm:

I fixed the angle of the prop by loosening the bolt at the top of the lower unit, removed the exhaust, and tapped over with a rubber mallet. With everything lined up, I re-tightened and re-installed the exhaust. This fixed the angle and the oil spattering issue.

I did not do anything about the high altitude jetting - but I did install a new spark plug. I did not do the lower unit oil, next year.

I ran it about 1/2 throttle for most of the time, never full. The engine ran perfectly. 16 foot sailboat, half throttle, filled with gear, and it ran about 4-5 mph according to my gps. Perfect for what I needed.

Hopefully someone can use my post in the future.

Andrew