Tohatsu 90hp starts then won't restart

[ozzydan11]

Hi

I just purchased a second hand boat with a Tohatsu 90hp (2002 model). I've used it twice now and both times have been lucky to get a tow home as the motor refusses to start. On the first trip it started first go, We stoped and fished for 30 mins started no prob. Then pulled up on a beach and it refused to start come time to leave. As i said i got a tow and once back at the ramp kicked it over and it started no problems.
The second trip it started no problems - i suspected that maybe i had flooded it first trip, so out i went. Again come time to leave it wouldn't start, starter motor turned and alarm sounded but it wouldn't kick over (as if their was no spark). I disconnected fuel line and kept trying to start it - no go. Reconnected fuel line and re primed it - no go. I even sat there and let it sit for at least half an hour - still nothing. So second tow home and would you believe it, it started again back at the ramp. i have given it the once over and noted that the foward control was a little loose - maybe neutral wasn't engaged properly, but i did put it and out of neutral a few times. Have checked the spark plugs they are new, no sign of fouling. There is also no overhaeting of the engine. One thing is that the oil reservoir has been bypassed (the previous owner didn't want to replace the filter so he bypassed it). Oil is mixed in the fuel tank. That's all i have discovered so far.
So now i have a motor i don't trust and no money for a mechanic to look at it untill next monthly pay.
Any suggestions will be greatly appreciated
Dan.

 

[pvanv]

Re: Tohatsu 90hp starts then won't restart

The problem is not likely to be Neutral-safety related. If the Neutral safety is engaged, the motor should not crank.

Assuming good compression (probably OK, based on good running when it does run), then the remaining issues are fuel and spark.

Probably not flooding, since you tested with fuel line disconnected... unless it was so severely flooded that the plugs didn't dry themselves off enough with extended cranking. I have seen that once or twice.

I would start at the beginning, and be as methodical as you can. Verify good, fresh fuel; Verify clean, dry plugs. Verify no places for unwanted air to gain entry to the fuel system; Crank and test.

The plug condition will speak paragraphs about proper combustion, so check them after a successful run.

Remember that these 2-stroke carbed motors require some "warm-up" lever on the control in order to start when cool. In other words, they may not start cold at all without some throttle. I have seen that complaint more than once on otherwise excellent motors, especially from second owners, who did not receive the owner's manual with the motor.

 

[ozzydan11]

Re: Tohatsu 90hp starts then won't restart

On doing further research i found some similar cases where a dirty carb was found to be the culprit. Might give it a clean and hopefully this will rectify the problem. I have checked fuel line and there is no air leaks.

 

[ozzydan11]

Re: Tohatsu 90hp starts then won't restart

Removed the carb covers and tried to start it today. It wouldn't start. I noticed the carbs are extremely flooded - fuel is spraying out of the front of the carbs and pooling on the base of the engine. Think i may have solved the problem. Time for a carb clean.

 

[PrplGld]

Re: Tohatsu 90hp starts then won't restart

Well, I was puzzled as to where you're boating this time of the year but then I googled your location. I suppose it's much warmer down under....