3.5hp 2-stroke problems

[sfellows]

We have a 3.5 relatively new 2-stroke outboard (Tohatsu). It starts from cold OK, runs OK, but invariably after we use it and try to start it again when the engine is still warm it just will not start. We've seen lots of these engines being used so clearly they are reliable, but ours just is too unreliable when warm.

Any ideas what we are doing wrong?

 

[Rappey]

Try a new spark plug ?

 

[VicS]

We have a 3.5 relatively new 2-stroke outboard (Tohatsu). It starts from cold OK, runs OK, but invariably after we use it and try to start it again when the engine is still warm it just will not start. We've seen lots of these engines being used so clearly they are reliable, but ours just is too unreliable when warm.

Any ideas what we are doing wrong?

I agree with Rappey ... try a new plug first of all.

Are you trying plenty of throttle and no choke ?

Wondering if the carb is flooding slightly due to a badly seating float valve ... ??
Are you leaving the fuel tap open ? If so try shutting it immediately after, or even a little before, stopping the engine. If that helps replace the needle valve and seat 1-19 and 1-20 in the attached diagram

 

[thinwater]

Are you using the choke? Warm you should not. These motors are prone to flooding. Try pulling with the throttle wide open, to clear. (I had one for many years)

 

[Kelpie]

If it's the one with the gear shift, try running the carb dry every time you use it. You'll soon get a feel for how soon you can turn the tap... it's kind of fun... especially on the 2.5 which doesn't have neutral

 

[Snowgoose-1]

I have a 4hp 4T that starts fine from cold as long as I squeeze the bulb from the external tank till hard. I found that when the engine was slightly warm I still had to do the same. I'm guessing that your engine is gravity fed. May be worth , as mentioned by contributors above, to give it plenty of throttle when starting whilst warm.

 

[Rappey]

Ive found my usually reliable engine can become a right pain in the butt even to the point where it wont start at all if i lay it on its side.
Seems to start again next day.
Keep it upright and its faultless.
My original spark plug failed at very low hrs . It got me out to my boat fine. I got back from a sail and once in the dingy i finally concluded my outboard was not going to start. Nice, now i only have to row against the wind and tide for nearly a mile to get back.