Old Yamaha 3.5hp - advice please!

[Erin]

Clean the carb, change the plug and pop a bit of oil in the cylinder to help it turn over, then give the cord a pull. What have you got to lose if you're not keeping it?

I would expect the oil on the shaft to be some residue of the grease in the collar. I get that on my 2.5.

[Downhilldai]

Originally Posted by willk

A query: which length do people generally mean when they refer to "Standard" shaft? 20"? I've seen the term on here a few times but couldn't match it to a specific size range in the posts? Is there a common sizing between Short and Long that I've missed

Here goes:

Sensibly, starting in the middle, with longshaft

Longshaft is for a 20" - 21" transom. Planing type motors are 20" from the underside of the saddle to the cav plate. Smaller hp motors, eg auxiliaries are 23", giving the prop more 'bite' under the transom.

Standard shaft (often mistakenly called short shaft) motors are 5" less than their longshaft brethren, for 15" transoms.

Extra Long motors are 5" more than the longshaft ones, for 25" transoms

Ultra long motors, sometimes referred to as XXL are 10" more than longshaft, for 30" transoms.

Short shaft are 12" and only likely to be seen on race motors.



I think .......

[willk]

Thanks for that DHD, yes I was finding the Short/Standard thing confusing. I'm hunting for a SIB and motor. Many of the sales websites list these sub 3m SIBs as requiring Short Shaft, but this will be 15", whatever they call it.

This brings me to another newbie question, when actually measuring the engine (if checking secondhand lumps) will the length from bracket to cav plate be exactly 15" or are there a wider range of possibilities? i.e. 14" to say, 18"?

Thanks in advance

[Downhilldai]

Originally Posted by willk

when actually measuring the engine (if checking secondhand lumps) will the length from bracket to cav plate be exactly 15" or are there a wider range of possibilities? i.e. 14" to say, 18"?

Most low hp motors for SIBs will be 18". Once you get up to around 8-10hp, they'll be 15", 'cos they'll plane the boat, so need the cav plate on top of the water.
Although I've measured a few over the years, I haven't noticed any size other than 15" or 18", but that doesn't mean that other sizes in between aren't around. If you find one you think will suit, post the details and I'll check whether it'll do the job.

[9D280]

Group 1)
I suspect your "oil leak" is just the grease to make it steer that bit more easilty (My Johnsorude aux has exactly the same arrangement).

Is the defineition of "long" not different for the diddy motrors?

Group 2)
- Coz it's there so it has to be done!
- coz it gives you an excuse to buy a similar vintage big yammy for the back of a searider!

....and welcome to the world of engine resurrection!

[willk]

Originally Posted by 9D280

- coz it gives you an excuse to buy a similar vintage big yammy for the back of a searider!

....and welcome to the world of engine resurrection!

...ask me again after the lobotomy!

No, I'm going to sell it to donegaldan. He really needs it to go with his 1986 Yammie 50. I haven't told him my evil plan yet, so this will be a nice surprise