Yamaha 8A Outboard (Old)

[liamo]

I have recently acquired an 8A Yamaha outboard. Serial no 647 S3148. No idea of age.
I wish to do a service of above but need a manual. Can anyone help?
I am getting a good spark from the lower plug but the upper one is very intermittent. Is this a coil problem? Any help greatly appreciated.

 

[VicS]

Check the sparks from the leads. Bad spark could well be a bad coil. If the coils are separate it may be possible to swap then over to check. Replace though if any signs of damage to the insulation.

It should be possible to ID the age from a "Year letter" see HERE for the key

You'll find parts lists and diagrams back to 1984 and owners manual back to 1998 HERE

 

[liamo]

Yamaha 8A outboard.

Thank you VicS for your reply. I do believe that the outboard is circa 1970 and hence too old for the for the manuals/parts lists on the Yamaha site. Appreciate your assistance.

 

[seanfoster]

Regarding the coils, I had a problem with mine (the ht lead had come away form it, and you can't replace them as they are sealed into the unit).

The original Yamaha part was discontinued some time ago, although I did see one available for nearly £160!

I did a bit of detective work and found out they were the same coils used on Yamaha motorbikes, (the FS1E amongst others) and found an online motorbike parts dealer. Got 2 new coils for £15 each!

Exactly the same parts, mounting holes etc.

 

[liamo]

Yamaha 8A outboard.

Thanks Sean,
I shall troll the net for a bike coil. Do you perchance know the part number?
Mine is CM61-21. Is it the same for bikes or is there an equivalent?
Regards,
Liam

 

[seanfoster]

PM sent, but for anyone else's info, the 6/8a/b and P165 use the same coils as the Yamaha FS1E, DT50, DT80, RD50, RD80 2 stroke motorbikes (plus lots of others).
You can find the part here:http://motorcycleproducts.co.uk/catalogue/ignition-coil-yamaha-fs1e-197476-p-70043.html

I've had two and they are exactly the same spec, mounting holes etc.

 

[Jmak]

Yamaha 8A 647

A neighbour recently gave one of these, been lying in his garage for a few years.An 8A 647 longshaft. It's a 71-72 model (http://continuouswave.com/whaler/reference/yamahaModelGuide.html)
I've had it on a 13ft dinghy starts easily and runs but cuts out, usually on full throttle.
Cleaned out and blown through the carb and fuel pump inlet and pipes but still cuts out in barrel test.
Anyone know where you can get service parts for the carb and what fuel mix?
If Yamaha pioneered 100:1 in 1984 this must be 50:1 or even 20:1 ??

 

[sagpeter]

Hi Gents,

is anyone active still from this thread? I'm trying to fix an 8A with my dad, and it seems we ran into a similar coil/ignition problem.

Do you have the service manual by any chance? I've been searching for it high and low but no luck.

Thank you!