Old Yamaha 3.5hp - advice please!

[willk]

Already I know this is a mistake

Anyways, I knew that this puppy was buried at the back of our shed at the old ranch. I resurrected it today, making homeless a nest of mice and some starlings in the process. The side of the shed fell out too

I think I need some people (Group 1) to tell me how to make it go and
I think I need some people (Group 2) to tell me WHY I should make it go

FWIW, I don't need an auxillary and I don't have a small boat. But I feel strangely compelled. Too much time on RIBnet I fear.

The Da bought it new back in the 1970s as an aux for a wee Sheltie and I don't reckon it's done more than 3 or 4 hours work. Ever. I think it's a long shaft but you guys can/will tell me if I'm wrong. I think someone on here mentioned that they are air-cooled. The tank will need scoured for rusticles.

Any of Group 1 care to give me a quick checklist of stuff to do before a test-fire?
Any of Group 2 care to come up with a plausible use for this thing?

It appears to be in exceptionally good shape with just superficial rust spots on the tank. The prop turns when the starter is pulled, I don't know if this is normal or the throttle is "in gear" or what as I don't recall if it had an idle position once running. At least it's not seized.

I'm thinking:
Clean the tank
New spark-plug
Clean the carb
fit a wee fuel filter
Change the oil in the leg
Check the action on the throttle

Does anyone know of a manual or other info source for these models?

[BogMonster]

Group 2 input:-

You should make it go because ... then you will have a little engine without a home which will justify to the Financial Controller that you need to buy a little SIB to put it on for messing around with, as it would be a waste otherwise and it is a family heirloom so you really shouldn't sell it

[Nos4r2]

Group 1 input.
Put some premix in it (50:1, motorbike 2 stroke NOT tcw3) and see if it pisses out of the carb. If it does,
take the floatbowl off, clean it and blow the jets through.

Then try and pullstart it.


They are really nice simple beasties. If it starts when you put fuel in and appears to run OK then it's fine. Give it a gearbox oil change and so on after-and don't bother faultfinding on it unless it refuses to start.

[Polwart]

Group 2 input: you should get it going because for next to no cost you'll get it in good order, and probably flog it on ebay for probably enough to get:

1. Half a dozen reasonable bottles of whisky OR
2. A good weekend of boating with your gas guzzlers OR
3. About 0.1% of the value of your dream boat OR

[willk]

Thankee kindly Gents!

All good advice. If it was workable on a SIB, I'd certainly lean to that. However, (see pic) I think she's a long shaft - is that doable, if only for farting about in?

There is a small oil leak on the shaft (circled area), I guess that this is a Bad Thing, although I see oil seals still available on the internet...

I've found a full parts catalogue online but so far, no owners or shop manual. Anyone? Obviously I don't want to spend much (anything ) on it, although I see a similar one (maybe a 3.5AC with Neutral?) on fleabay sitting at £189 with time to go

Petrol from 1980 still burned well in a pan, but then, I guess it's been in the ground for a while before that too

[willk]

The picture, doh!

[Nos4r2]

Originally Posted by willk

The picture, doh!

There's no oil bearing part in the circled area, it's a short shaft , and if it's got fuel from 1980 in it you really need to clean the carb out and change the plug before trying to run it.

[BogMonster]

Originally Posted by willk

All good advice. If it was workable on a SIB, I'd certainly lean to that. However, (see pic) I think she's a long shaft - is that doable, if only for farting about in?

Limited experience: I ran my longshaft 6hp Johnzuki 4st aux briefly on a small (2.3 ish) cheap no-brand SIB that Dad had ordered as a tender to his little yacht, it was not ideal as it was a 6hp engine on a SIB rated to 4hp and when you opened the throttle too much (and nowhere near full...) the transom used to try and tie the rear half of the tubes in a knot, I am not sure if this was the excess power or possibly the extra "twist" on the transom from the prop being 5 inches lower - if you think about it, the torque reaction at the transom is increased somewhere around 33% by having the shaft 20" down instead of 15" down. Also of course you will need 5" more water

I'd say it will be ok for farting about in but probably best have a SIB rated for a higher power than the engine if you want to use it much. As it was I found that I didn't take to life on the South Atlantic in a boat about as long as I am tall with my arse that low to the water, and as I didn't want to break his SIB before he had even used it I quickly gave it back

[willk]

Originally Posted by Nos4r2

There's no oil bearing part in the circled area, it's a short shaft , and if it's got fuel from 1980 in it you really need to clean the carb out and change the plug before trying to run it.

Well, good news on the shaft length (never thought I'd be glad to hear I had a shortshaft, but hey!) that means she's a keeper and I will employ The Luxton Gambit* over the next few months as the summer SIBs come on the market.

But first she must run! Yes Nos, the fuel is rank (its been in a shed since 1980, srsly) and I've not even turned on the fuel knob, never mind tried to make her run. There IS goo oozing from the leg but I'll get to that in due course, maybe it's just a light fraction of old grease running out now that I broke the crust??!

I've had the covers off since the first post and I must say, the internals seems to be in as good a nick as one could hope for, given the many years in storage. The throttle engages, as does the choke and there is precious little corrosion. Fun and games ahead so.

_________________

* That was Genius, Stevo!

[Polwart]

Originally Posted by Nos4r2

There's no oil bearing part in the circled area, it's a short shaft

does 20" not = long?