9.8 Tohatsu Bucks

[rocket rich]

well just when I thought I had the answer to my never ending troublemaker 9.8 it comes back to haunt me.. I know every one is a gura?? I'm a stupid _ _s _ . This motor is going be the death on me. Now with just me in the boat it want''s to rev to not wot, it starts that _s _ _ _t again. so to stop it I lower it another hole seting the motor lower? looks like 5700 rpm's is when it does it. ????? Maybe?? What am I to do???????

 

[pvanv]

If you think that the ESG may be engaging below 6000, but 5700 is OK, you really are doing OK (working properly within 300 RPM of ESG). But the ESG shouldn't be engaging below 6000. If it is, the CD should be replaced. The only way to definitively verify that will be at your local dealer.

If you have changed weight around, and might have the motor too high, you might be ventilating. If so, it might ventilate more in corners at speed. If ventilating, make sure the motor stays low enough. Is this happening when you have 2 people in the boat?

 

[rocket rich]

99 % of the time it''s just me in the boat, I like it that way. this pass week has been another learning week. I did just what you said. I lower the motor as low as it would go and the bucking / Ventilating stopped, and I can get around 5740 RPM's not bad . what I don't understand is why all the changes, nothing changes in the boat, ?? when I got the motor I had to change the transom height now it's as low as I can go as far as the motor adjustments. Don;t tell me to lower the transom height??

 

[Sea Rider]

RR,

The issue about installing a new whichever brand engine you bought onto a whichever brand boat you have is that in most cases you won't get a perfect spot on engine/transom height match. Combo will surelyt plane, but won't get the max thrust out of that portable engine specially if running underpowered engines on boats rated for much higher HP engines, as in your particular case.

Instead of blindly adding wooden shims, playing with engine trim, boat ballance endlessly, it's just a simple matter of pulling head at back transom and checking at which tail height is water flow passing by at full plane at speed. Transom heights/trims affects directly engine top perforrmance. Too high will give aireation issues, too low will give water splashes out/over transom.

Next week will be installing a Tohatsu L engine on a L transom Rib, L to L should match, will post some pics regarding initial dry set-up installation and pics when combo is on plane to see if theoretically have matched the sweet engine/transom height marriage. (Will be poested under : Which One Topic)

Happy Boating

 

[rocket rich]

I was very happy with the trim and setup of the motor, Why does it change when I haven't made changes?? Now I can't lower it any more with out cutting the transom?? That doesn't make much sense?? It must be the devil made it do it??