ARRRRRR Tohatsu 9.8 --- Won't Start --- Help Please ??

[Stroth]

Last week I bought a 2010 Tohatsu 9.8 four stroke. Model Number is: MFS9 8A3

I bought it last Friday. Tested it with the seller and it all looked great.

Put fresh gas and Stabil Marine in it. Last Saturday it ran great. I had it out for about 3 hours or so. Perfect. No issues. When I stopped I disconnected the gas line and let it run until it died.

I stored it in my garage.

Today I went to take it out. Re-attached the fuel line, pumped the bulb maybe 3 times and tried to start it. I stupidly did not choke it. After it would not start after a bunch of pulls I realized that I did not have the choke pulled. Thinking I flooded it, I waited for about 20 min. Tried again with no luck. Changed the spark plugs. Still no luck.

I have checked the spark and I have spark with both plugs. If I pump the bulb gas will come out of the bottom of the carb so I know it is getting fuel. The red oil light will go on as I pull.

If it was an issue with the kill switch I would not get spark right?

If I did flood it, wouldn't the issue resolve within 30 minutes or so?

What should my next steps be? Should I just bring it to a dealer?

I am really bummed. I did a lot of research and saved for a long time to get this motor and thought they were reliable and a solid buy.....

Any help is much appreciated!

Stroth

 

[pvanv]

1. You will not flood the motor by not choking.
2. If you pump the primer bulb and gas comes out of the carb, the float valve is stuck open, and the float bowl is overflowing. In that case, you are getting WAY too much fuel. Super flooded.

Yes, it's a great design. They are good motors. Lightest in class, etc., etc. Odds are that the float valve needle is jammed open (down). Tapping on the side of the carb (when full) may allow it to close again. If there is oxidation on the aluminum of the needle, it could be a little rough, and not slide well in the seat bore. If so, carefully burnishing sides of the aluminum needle may polish that away.

 

[Stroth]

Thanks for the help!
This morning I tried again with no luck.

I took out the drain screw of the carb and gas literally poured / shot out. It all looked clean to me, nothing gummy or dirty, just nice clean gas going all over me. I would say a cup or more of gas came out.

Should I try again after it dries out?

Is it possible that I just super flooded it and it went it to some type of shut down mode?

Matt

 

[pvanv]

Thanks for the help!
This morning I tried again with no luck.

I took out the drain screw of the carb and gas literally poured / shot out. It all looked clean to me, nothing gummy or dirty, just nice clean gas going all over me. I would say a cup or more of gas came out.

Should I try again after it dries out?

Is it possible that I just super flooded it and it went it to some type of shut down mode?

Matt

No. Your carb float valve is stuck wide open. Try tapping (hard) on the side of the carb after a couple of priming pumps. Failing that, the carb will need to come off the motor and be repaired.

 

[Stroth]

I let it rest for most of the day.

Tapped the carb a few times on the top.

First pull it fired right up!

I took it out and ran it for an hour. No issues.

What did I do wrong?

I must have pumped the bulb too much when trying to start it and just super flooded it right? When I drained the carb that must have reset the float right?

I need to review my cold start procedure.

1. Attach fuel line.
2. Primer Bulb: Since it is primed already, bulb will be firm. One squeeze? No squeeze and try to start? If you attach the line and the bulb is firm do you have to squeeze at all?
3. Full choke, pull.
4. Warm up a bit, no choke.
5. Warm up a bit more.
6. Run

When I am done. I have been told to run the carb dry. Do you all do this by idling or do you have it in gear and go till it dies?

THANK YOU THANK YOU THANK YOU

 

[pvanv]

Odds are the float just stuck. Used to happen with carbureted cars all the time. You likely did nothing wrong. No, you cannot prime too much if the float is working properly. The bowl will fill, and the float valve will stop the flow of fuel (kind of like the fill valve in a toilet tank).

Since it is prudent to either run the carb out at the end of the day, or drain it -- especially if sitting for more than a couple of days --, you will need to prime with the bulb. (The carb will be empty when you get ready to go.)

Yes, some choke is needed when cool. The colder, the more choke, and the longer it needs to run with choke. That is because cold gas evaporates more slowly than warm gas. (Think of a pot of cold water vs a pot of boiling water, vaporizing away.)

If you know 100% that you will be running again tomorrow, no need to empty the carb. OTOH, if there is any question, run the carb dry. It can be at idle (may take 5 or more minutes), or in gear under a slight load. The reason for that is that today's gas is pretty dirty, and if left in the bowl... as it evaporates, it will leave a residue not unlike what you see if coffee or tea is allowed to evaporate from a cup. That varnish can restrict flow through narrow carb passages. Also, if there is any ethanol, there will be some dissolved water, which is corrosive to aluminum carburetors.

 

[isaksp00]

Stroth, what Paul suggested is what I do with my Honda 8, and other than unexplainable occasional issues where the low speed jet seems to clog and I have to push a plastic "wire" through it, I have had no problems.
One loosely related comment that I had never realized - at times I'd pump my bulb after having run the carb dry the previous use, and it didn't seem to pump well, that is, did not get hard. I found a post somewhere that said the bulbs should be positioned vertically when pumping, so that the outlet side is straight up, NOT sideways. Since I do that it always pumps and gets hard after maybe 4 or 5 squeezes (wow, that sounds profane ).

 

[Sea Rider]

When running carb dry, will need to prime bulb with arrow facing upward, primes much better and fully than doing it horizontal, just prime till bulb is firm, doesn't need to be rock hard. Will need tu pull choke out for OB to start faster..

Happy Boating