Need Tohatsu help

[daveracerdsh]

Went testing a week ago Sunday....saw close to 83 in D stock hydro...not bragging or anything like that....went to Yelm and went slower and slower and slower....down to 74 at full throttle 1st heat Sunday. Boat is fine, compression is good (135 on all 3) plugs look good, no fuel restrictions, motor is not 4 cycling. Motor has new rings in it...had bores checked out for straightness and piston to wall clearance...crank was checked for straightness, new reeds, new kill switch....I have done or will do all of the obvious things.. carbs, seals etc..What could cause a fresh race motor to all of a sudden loose 9 mph from testing to the first race? I am somewhat embbarased to be asking for help on this..but I do not know what else to do. Any help sure would be appreciated. Dave

[john527]

this may sound stupid, but do you have your gas and oil mixed right?

[daveracerdsh]

Tohatsu

Yep...not stupid at all. 24-1 gas to oil. Testing fuel was same as race fuel...along with same oil out of same bottle. Fuel stayed dry in trailer for the week. I will be buying fresh stuff for this weekend though. Thanx for the tip.

[kampenracing]

Tohatsu

We have had the same problem with ours, it never ran right since new, we changed everything from top to bottom, finally got it running right once while testing and it took a crap again. We went through it again and will try it again soon and sure hope it will run

[daveracerdsh]

testing

what did u do to it? dave

[kampenracing]

Tohatsu

The one time it ran good, it ran for good for 4-5 laps and then fell on its face. We have not been able to get it to run since. Every part and piece on this engine has been changed. Once we changed it all over again, it still wouldn't run. This time the fuel filter element was in upside down. We haven't tried it yet this year. I know it's not setup or props because I have another one that wins for me consistently.

[kampenracing]

Tohatsu

When it would run it was always 10 mph slower than everyone else's.

[daveracerdsh]

Tohatsu

A number of people have had the same issue with motor....it is smoking fast and all of a sudden it falls on it's face. I wonder if there is an internal issue with powerhead......so many cycles on block...cooling and heating etc...then something gets warped. Dunno. Have u changed all the electronics?

[bill boyes]

Outside of the box. Think just maybe the gearbox might be bad. Does the motor have a tuned pipe. Yamato's will sure fall on their face with a broken pipe.

[kampenracing]

Tohatsu

Replaced electronics, and just about every other part on the engine. It was slow when it came out of the box.

[jeff55v]

Are you guys welding your cranks?
Add: I welded my crank from day 1. I punished my motor through 4 Top O's, and various circle races. I never had a reason to tear mine down from 2007 to 2012 it ran consistently well and held compression very well. Just spark plugs, reeds, and a fuel filter through all that racing.

[mercguy]

very doubtful..........

A number of people have had the same issue with motor....it is smoking fast and all of a sudden it falls on it's face. I wonder if there is an internal issue with powerhead......so many cycles on block...cooling and heating etc...then something gets warped. Dunno. Have u changed all the electronics?

I have probably put more time on my Tohatsu than most people in the country and have NEVER had the problems being mentioned..........

it all comes down to basics......you must have COMPRESSION, SPARK, and FUEL, if any one of those are out of whack, then you will have issues.....

1) pull spark plugs........do they all look the same?
2) inspect reeds...are any busted?
3) check carbs (main jet plugged?)
4) check TIMING for full advance
5) ck fuel pump diaphragm...make sure there is not a hole in it...
6) fuel, make sure there is not a restriction and fuel tank is venting properly
7) make sure crank seals are not leaking
8) inspect all ignition ground wires for cleanliness and tightness
9) rev-limiter wires......make sure they are disconnected and the bare wires are taped up and not touching a ground
10) ck gear oil and its condition, if metallic...you have gear problems...
11) ck your GPS..........83mph???
12)..............if you are still lost........bring up the powerhead to me........we can fix it (not by the weekend though)...............or I can loan you a VERY GOOD powerhead...............

....how's that?

[daveracerdsh]

tohatsu

crank is welded......no tuner pipe in center section. lower unit turns over fine. dave

[john527]

Just an idea!

[pstock800]

tohatsu

I had this problem with mine. from new , do 2 laps and it would fall on its face. it would loose comp, in number one. run a hone through it and would do 2 laps and same thing. stripped it bored it checked crank, new reeds all seals, never had a problem again. my motor isnt the tightest but it runs great.

what did you put in it for gaskets and seals. dont use the mallory gasket kits, i didnt have good luck with them.

call alex up in maine and get them from him.

check your head bolts. the strip easy.