1999 nissan 30 h.p. 2 - stroke electric start

[Chad Hendrix]

Subject-motor real cold natured and wouldn,t run at idle sometime.o.k. Motor has less than 200hrs on it.replaced fuel tank and primer bulb hose and fittings,still didn,t fix problem.next thing that was done was carburetor was cleaned by ultrasonic cleaner by technican and a water pump impeller replaced.next i took boat fishing and it ran hot,so i checked thermostat it was sticking and replaced it and same thing happened.again cared it back to technician and they replaced the upper head gasket and had to idle up motor a little. Again went to try out motor ,got up on plane for about 1/4 of a mile ,same thing motor quit on me .tried a few more times to run motor ,it cranked up only with the fast idle lever up.so i put motor on trailer and went home. I later took off cylinder head cover for inspection and noticed excessive carbon buildup on pistons and cleaned them and the water passages were clear in the cylinder head.what else good be wrong with my motor?

 

[Chad Hendrix]

Re: 1999 nissan 30 h.p. 2 - stroke electric start

Subject-motor real cold natured and wouldn,t run at idle sometime.o.k. Motor has less than 200hrs on it.replaced fuel tank and primer bulb hose and fittings,still didn,t fix problem.next thing that was done was carburetor was cleaned by ultrasonic cleaner by technican and a water pump impeller replaced.next i took boat fishing and it ran hot,so i checked thermostat it was sticking and replaced it and same thing happened.again cared it back to technician and they replaced the upper head gasket and had to idle up motor a little. Again went to try out motor ,got up on plane for about 1/4 of a mile ,same thing motor quit on me .tried a few more times to run motor ,it cranked up only with the fast idle lever up.so i put motor on trailer and went home. I later took off cylinder head cover for inspection and noticed excessive carbon buildup on pistons and cleaned them and the water passages were clear in the cylinder head.what else good be wrong with my motor?

 

[TOHATSU GURU]

Re: 1999 nissan 30 h.p. 2 - stroke electric start

Anything could be wrong with your engine...You have to test the engine's systems to see which one is causing the problem. Then you test and/or inspect that systems various sub systems to find out which one is the culprit. Anything else is just a wild guess.

 

[pvanv]

Re: 1999 nissan 30 h.p. 2 - stroke electric start

You did not mention model; Year is unimportant for servicing, but precise model/serial is everything. I take it you have an NS30A4.

If I understand correctly, you have been having stalling issues, especially near idle. As Elvin explained, could be a lot of things, so if you are going to work on this yourself, get a Factory service manual, available from any dealer (including me), and begin troubleshooting with a plan. You need to verify the mechanical, fuel delivery, and ignition systems.

I have no idea what an "upper head gasket" might be. The NS30 only has one head gasket. Likewise, I don't quite understand what a "cylinder head cover" might be. Maybe the head itself? If you pulled the head off, you will need a new head gasket, and will want to torque the head bolts correctly as you reassemble the top end of the motor. That info is in the Factory service manual, and you would be driving blind without one.

9 times out of 10, stalling near idle is a carb or other fuel system issue. But you must test and diagnose to be sure, or you are just guessing. If this seems like something you can do yourself, cool. Gather your tools and test equipment (and that trusty manual), and start into it. If the concepts seem daunting, get the motor to a dealer.