Tohatsu 2 Strokes 8 to 9.8 Conversion.-

[Sea Rider]

Is there someone who has done this conversion, if so, share your experience...

Happy Boating

 

[pvanv]

Depends on serial number. Early M8B cannot be upgraded to M9.8B. The later models can be done... they use different carbs, so it is a bolt-on upgrade.

 

[Sea Rider]

Paul,

Are newly released Merc 8 HP equivalent to Tohatsu M8B model. It's a local Customs auction, at just $ 1,200.00 can't possibly say NO, hope there's a S one as seems to be L ones, fingers crossed.

Surfing the Parts Catalogue & Service Manual seems that there's only 3 things you need to swap/adjust for a full 9.8 conversion are :

- Swap 8 HP carb for a 9.8 carb.
- Swap 8 HP Coil Plate Stopper for 9.8 model.
- Advance timing 22? to 26? along carb synch if needed to open butterfly fully.

Optional :
- 1 less prop pitch to pull wot revs up towards max wot rpm range if in need for OB to rev higher.

Conversion should be a nice walk in the park on a light windy sunny day..LOL!!

Happy Boating

 

[pvanv]

A new Merc 8 would be a 4-stroke in the US, and it would be a Tohatsu power head. In that case, just swap for the 4-stroke 9.8 carb and you are done.
I have no clue what they sell in the 2-stroke world. Might be a modern M8B, or even some other brand.