8MSH Long shaft HELP

[mitch184]

OK, so I found a good deal on a 2006 8hp 8MSH 2 stroke motor. Serial # is 6NO S 1021195 J.

This is a 15" short shaft, but I called Bay Kit Manufacturing and they had a kit for 6NO serial number 8MSH motors. No problem, order the kit.

Kit shows up, the spacer is way bigger than needed, the threaded rods and water pipe extension are too big but the dowel pins and the driveshaft extension are the right size. Called the vendor, and they said that this motor was made in France and it's an oddball housing that they've never seen before. I'm guessing there's certain breaks in serial numbers that wasn't accounted for.

Help needed.... where could I find out if this motor was ever made in a long shaft? Also, I know you can buy 2 stroke 8hp long shafts today in Austrailia, is there a parts catalog that just covers those motors? If so, I could just buy a long shaft middle housing and bolt it on.

Any other advice or direction would be greatly appreciated. Otherwise, I guess I have a sweet running, low hours 8MSH for sale...

[boscoe99]

There were no 8MLH models offered here in the USA from 2001 through 2009, when the last 8MSH was available.

In 2000 Yamaha US offered an 8MLHY model.

2000 8MLHY Yamaha Outboard Parts

In the vast majority of instances it is better for a number of reasons to sell what you have, and then buy what you need, than it is to try and convert a model from one configuration to another.

[mitch184]

Yes. That is becoming my reality.

However, the 6N0-G5111-10-4D Upper casing for that 2000 8MLHY will possibly mount up to the lower casing (unit) and bottom cowling used on my engine.

If that was the case, the swap seems fairly easy. It would be nice to make sure it lines up before ordering the $200 housing, but I guess it's not too terribly expensive.

[boscoe99]

What country are you in? You mention Australia. You can find Yamaha parts catalogs for the models that are offered in Australia. I see an 8CMHS being offered there in 2006 but no 8MHS model. The is an 8CMHL model shown.

Here is what you can do if you are so inclined:

Go to the Yamaha USA parts catalog at www.yamahaoutboards.com

Open up the catalog for a 2006 8MSH model. Which should be the same motor as the one that you have.

Open up the catalog for a 2000 8MLHY model.

Compare the parts from one model to the other that you think might be affected by a difference in shaft length.

1. Bottom cowl is the same part number
2. Upper casing part number is different for the S versus the L model.
3. Lower unit part number is different for the S versus the L model. Difference is the drive shaft length and the shift cam length.
4. Water pump tube part number is different for the S versus the L model.

I give and I give and I give. It is never enough. Buy them their books, send them to school, and they eat the pages.

[mitch184]

I'm in USA. I actually already compared the 2000 8MLHY vs my motor. Hence my comment about the common bottom cowling comment.

I have a driveshaft spacer and shift rod "spacer"

I was more bouncing the idea off you because it seems fairly straight forward to me at the time like I was missing something. Or if it was easier to just buy the mid section and lower unit off a 2000 8MLHY and swap everything over. That's all.

Thanks

[boscoe99]

Easiest way would be to sell what you have and to buy a long shaft model.

Next easiest way would be to find and buy a long shaft model that needs a new power plant. Then take yours and move it over to the old motor.

Next easiest way would be to buy a new long mid-section and the water pump tube and install same together with your Bay Mfg. stuff, minus the spacer.

Bay has been working with Yamaha for years and years. I am quite surprised to hear that stuff they are selling to convert a short shaft model to a long shaft model won't work. The short upper casing, to which a Bay spacer is attached, has been around for years and year. Hope they are giving you some money back.

6N0-G5111-00-4D YAMAHA CASING, UPPER

I converted an F250TXR (long shaft) to the the F250TUR (extra long shaft) configuration and it was a snap. Stuff just bolted together.

[mitch184]

Yes, they are very puzzled but have research and confirmed several times that they don't make a spacer with the same outer dimensions/shape as my lower unit. They said they believe it's because Yamaha never used a spacer for the long shaft motor, but rather always used a long shaft housing.

Bay Kit Manu. is great to work with though and will refund me the entire amount.

I would love to find a new motor altogether, but they are next to impossible to find. I did find the entire mid section, bracket and lower unit off a 2000 Long shaft for sale. I think I'll return the bay kit and buy those parts. I believe I'll be able to make it work. I'should also end up with a spare lower unit for when/if I rip the skeg off the current one.

In your experience, and I couldn't decipher the schematics to understand, besides the casing, water tube, shift rod and driveshaft, I would assume the something with the exhaust has to be extended as well? Is that true?

[boscoe99]

Without going back and comparing the two parts catalogs again I don't recall anything in the exhaust that needs to be changed. The same exhaust manifold is used in both the long shaft and the short shaft models.

6N0-G1131-00-5B YAMAHA MANIFOLD, EXHAUST 1

But don't take my word for it. Do your research. Know for yourself. Compare the long shaft model with the short shaft model by using the parts catalogs. The same way that an engineer would do it if he was to develop a conversion kit.