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18hp 4 stroke Tohatsu Carb

wam

New member
"Apologies if this is posted t

"Apologies if this is posted twice...new user.

Have followed the Tohatsu forum for months, and have a rough running 18hp. Believe the Guru is right, and bad fuel, operator error of leaving fuel in the engine is the culprit. Order the service manual, and have been following what info is there...but a few questions regarding the carb.

1. I have the carb off, and the float bowl removed, and have removed all rubber gaskets and rubber plug inside the carb body that covered one of the jets. Do I have to take the butterfly valve apart? Take that c-clip off the shaft, remove the 2 phillips screws holding the brass butterfly and then the whole thing just slides out? There looks to be a rubber washer around the mess of springs on that shaft, and a rubber boot...I guess I need to get all that off before putting it in the carb cleaner bucket to soak for 4 hours?

2. And finally, what tool to you experts use to get that bolt on/off, the bolt nearest/under the flywheel, that holds the carb body in place. That plastic air box is really in my way! Open-end wrench, 1/4" socket, smaller fingers?

THanks much -
Wayne"
 
"1) No and three hours sho

"1) No and three hours should do it.

2) Screw driver on an angle...The screw isn't that tight. But, the factory method calls for you to remove the starter for access."
 
"Thanks for the feedback. Jus

"Thanks for the feedback. Just so I'm perfectly clear...

1) So it is ok to soak the top half of the carb, with the rubber boot and rubber grommet around the springs, in the carb cleaner for 3 hrs?

2) I failed to mention, it's a 2003 model, and the bolts are 10mm heads, with no slot for a screwdriver?

Thanks...."
 
"1) No, you have to remove

"1) No, you have to remove the rubber bits before you soak it.

2) I remember it as having Phillips head/10mm bolts...I could be wrong. Regardless, pop the starter off for access."
 
"I also have a 2003 18 horse 4

"I also have a 2003 18 horse 4 stroke tohatsu. It has been a terrific engine until the ethanol mixed gas became so prevalent. If you don't drain the bowl after running or simply disconnect the fuel line and let the motor run out of gas, you will quickly become an expert at cleaning carbs.

The bolts are 10mm and do not have Phillips heads on my motor. The best way I have found to remove the bolt is with a simple 10mm wrench or ratcheting wrench if you have one. I haven't found it necessary to remove the starter. It takes a couple of minutes, but is really quite simple. I have cleaned the carbs twice now and both times they looked relatively clean. I know the manual calls for soaking them for 3 hours, but all they really needed was a couple of blasts in the idle jet under the rubber stopper."
 
"Thanks for the real-world exp

"Thanks for the real-world experience Chad. I'll be running the engine out of gas from now on, when I'm finished.

My carb too wasn't all gunked up, but I've made sure that all the tiny holes in the jets are clear. I'm going to forego the soaking procedure, and put it back together this afternoon for a test run. If it's no better, then I'll take the carb off again, and tackle removing the butterfly valve and all the rubber pieces/parts, and then soak it as per the recommendations...I hope I can get it running back like it used to, because it is one fine engine when it's in tip top shape.

Thanks again for all the input folks...this forum is a great asset to guys like me who love their Tohatsu's, but live a fer piece from a certified mechanic."
 
"Ok,
Blew the jets out with


"Ok,
Blew the jets out with air, and visually, the carb looked clean, but it just would not run. So, I'll be taking the carb off again, and this time soaking it for the 3 hours in the carb cleaner after taking it completely apart and removing all the rubber components."
 
I just purchased an 02 9.8 2 s

I just purchased an 02 9.8 2 stroke Nissan with a long remote control box . Can you give me part #s I need to get it to the shortest length made. Thanks.
 
"Just a followup on the progre

"Just a followup on the progress....

Followed the recommendations, and completely disassembled the carb, removing all rubber/plastic comoponents, and soaked the entire thing in Berrymans Chem Dip carb cleaner for 24 hours (I know, 3 is suggested, but this thing called a job got in the way). Put it all back together after blowing all the orafices out with compressed air, pumped fresh gas in it, and voila...running like a top. Let all the gas run out of it, and repeated the process. Running perfectly. Still have some fine adjustements to make on the throttle stop, but other than that, once it's going, it runs like a new one.

Thanks everyone...and while not a Guru, I do know my 18hp 4 stroke carb, inside and out!

Wayne"
 
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