TOHATSU 90 troublemaker

[Playboy]

I luuv my Tohatsu, however something minor with it bothers me so I can´t sleep at night;
Starts good on first try, no power to get on plane, takes 6000 RPM on neutral (rev limiter removed) only 3100 on fwd, normally almost 6000.
As far as the naked eye can tell good spark on all 3 cylinders, when I squeeze the fuel pump (on fuel hose), fuel reaches all carbs. I have double checked the carbs.
#1 cyl. seems to run hotter than others, all filters cleaned, changed plugs + almost all other electrical components (from my other engine). Heat censor changed. Still not running can´t figure anything else,. Next I am going to give it a hard Mule kick.:devil:

 

[Silvertip]

Re: TOHATSU 90 troublemaker

Compression check is in order. How do you know #1 is running hot? How have you checked the carbs? Just because there is fuel AT the carbs does not mean it is getting INTO the engine. By the way -- 6000 rpm in neutral is an excellent way to turn an otherwise good engine into an anchor. An engine running on half its cylinders will still rev up freely as there is no load on it.

 

[Playboy]

Re: TOHATSU 90 troublemaker

Good compression, different temp on plugs (by hand method), My buddy is reving his tuned YAMAHA 15 hp over 13000 on neutral so 6000 shouldn´t be to much for a second or so, the general idea was just to check the revlimiter U see!

By the way my wife gave me this nickname just for playing around with theese 2-stroke sukkers.

 

[MOTION LINE]

Re: TOHATSU 90 troublemaker

Dear Playboy are you quite sure all oil seals (stefa på svenska) are in order?

Have you really taken all carbs in parts?
Next contact a good service man, which is not an easy task nowadays,...d8)

 

[Herra Raana # 1]

Re: TOHATSU 90 troublemaker

Hi, I am quite sure the guys at GRT can help why don´t you give them a call?8)

http://gumboracingteam.com/grt/

 

[TOHATSU GURU]

Re: TOHATSU 90 troublemaker

With the engine running in neutral, at 700 RPM, remove each one of the spark plug caps in turn. If your RPM goes up you have a spun crank. Almost anything can cause the engine to not get on plane though.

 

[Herra Raana # 1]

Re: TOHATSU 90 troublemaker

Hey guys, I happen to know exactly what is wrong with the engine, but first I have to mention to be carefull in naming your posts, TOHATSU troublemaker, do not blame your engine before you are 100% sure what really is wrong, in 98% of the cases the fault can be seen in your own mirror d, but back to the engine, remove the flywheel, clean everything, put it back together and drive. Do not forget one important thing, when you fill the engine with oil try to aim directly in the oil tank, othervise you will have exess oil building up all over under the cowl. That´s it keep it simple stupid, and Mr Playboy I want you to keep us informed wether I was right or wrong! You see I know what I am talking about and I am glad to share it with you. +o(

 

[Playboy]

Re: TOHATSU 90 troublemaker

Mr Herra Raana seems to be the # 1 Tohatsu guy, I did exatly as I was told cleaned all oil and yes there was plenty of it, put it back together and fired it up, SURPRISE SURPRISE the engine ran like never before, picked up some 2 knots.

Please Mr Raana I want more of your secret tricks, I have been thinking of reboring up to 140hp. pistons
is it possible?

 

[TOHATSU GURU]

Re: TOHATSU 90 troublemaker

And I just had to laugh!

 

[MOTION LINE]

Re: TOHATSU 90 troublemaker

115 and 140 (same engine) pistons can be used as bigbore pistons in 90 hp. Tohatsu, you only have to bore the cylinders and pay special attention to the squisband in the cylinderhead othervise damage will occur. This is a trick some racers have used for years, theese racers are cheaters (B, Johnsons on water) the engine is not homolgated with theese pistons. +o(
If you can´t afford the std 140 pistons go for Wiseco they will work just fine.

 

[deejaycee_2000]

Re: TOHATSU 90 troublemaker

Playboy .... you can re-bore that 90 to 110hp max, just a thought, never change the gearbox or modify the top on that 90, we've tried to convert the 90 tohatsu in the 140 as they are similar, but changing the crank and the gear ratio can result in a bad big bang .....

 

[gerald trentham]

Re: TOHATSU 90 troublemaker

Mr Herra Raana seems to be the # 1 Tohatsu guy, I did exatly as I was told cleaned all oil and yes there was plenty of it, put it back together and fired it up, SURPRISE SURPRISE the engine ran like never before, picked up some 2 knots.

Please Mr Raana I want more of your secret tricks, I have been thinking of reboring up to 140hp. pistons
is it possible?

 

[gerald trentham]

Re: TOHATSU 90 troublemaker

Mr Herra Raana seems to be the # 1 Tohatsu guy, I did exatly as I was told cleaned all oil and yes there was plenty of it, put it back together and fired it up, SURPRISE SURPRISE the engine ran like never before, picked up some 2 knots.

Please Mr Raana I want more of your secret tricks, I have been thinking of reboring up to 140hp. pistons
is it possible?

 

[gerald trentham]

Re: TOHATSU 90 troublemaker

i think i have the same problem with my nissan 90 hp.
where can i get puller removal tool to remove the flywheel

 

[TOHATSU GURU]

Re: TOHATSU 90 troublemaker

Any marine dealer or you can loosen the flywheel nut, bring it up flush with the top of the crankshaft and smack it. Be careful. It is an emergency method.