Tohatsu outboards, 4stroke, 8hp - 9.8hp ?

[Bscman]

I've got an opportunity to pick up a lightly used Tohatsu 8hp 4-stroke outboard for a great price.

Looking at the specs between the 8hp and 9.8hp, they appear identical (displacement, weight, size, etc).

Is it possible to convert an 8hp to a 9.8hp?
Any idea what said conversion might cost?

I know some of the older 9.9hp 2-stroke engines were basically de-rated 15hp motors, and they can be converted...hence by curiousity.

Also, anyone want to comment on Tohatsu's reputation or personal experiences with either the 8hp or 9.8?

Just kicking around a few potential ideas...thanks!
-Brett

[swedefish4life1]

You are correct:-$ small changes make more HP and the 9.9 to 15 are the same motor with differnt intake and other goodies:-#

[wolverine]

Tohatsu - Nissan - Mercury small 4 strokes are all made by Tohatsu.

Most 8 hp motors are de-tuned 9.9's. 9.9's are labeled that because a lot of lakes have 10 hp maximums.

You need to check the gearing as a lot of 8's are geared to be kickers on larger boats, rather than as the primary umph for small skiffs.

I looked at the Tohatsu website and both the 8 & 9.9 have a displacement of 29 cc (12.8 ci) so the difference is how they are carbed. What you will find is that converting to 8 to 9.9 specs to be quite expensive for the hp gain.

[Bscman]

Thanks guys, exactly what I needed to be aware of.
Much appreciated!

[Bodofish]

Tohatsu - Nissan - Mercury small 4 strokes are all made by Tohatsu.

Most 8 hp motors are de-tuned 9.9's. 9.9's are labeled that because a lot of lakes have 10 hp maximums.

You need to check the gearing as a lot of 8's are geared to be kickers on larger boats, rather than as the primary umph for small skiffs.

I looked at the Tohatsu website and both the 8 & 9.9 have a displacement of 29 cc (12.8 ci) so the difference is how they are carbed. What you will find is that converting to 8 to 9.9 specs to be quite expensive for the hp gain.

Just been scratching on this one. the 8 and the 9.8 are the same and the 9.9 and 15 are too. 9.8 and 9.9 are different. Yes all three brands are the same with different covers, price following the name. =)