nissan 9.9 no power.

[ryan_289]

Ive got a Nissan ns9.9b2 that im haveing issues with. It came on a boat I bought and wouldnt stay running. I cleaned the carb and she starts great and runs fine on muffs. I took it out today and it doesnt feel like its got any power. I couldnt get the boat to plane out. I dont think its the prop, the engine itself never seemed to rev up enough to get going. I didnt mess with the air fuel mix screw, could this be set wrong and cause this problem?

 

[TOHATSU GURU]

Re: nissan 9.9 no power.

Sure...But, it could be virtually anything as lack of power is a broad based symptom that can be caused by failures in all aspects of the engine. You can get a service manual and start the diagnostic procedures...Or, you can stop now and retire the engine. Carb parts and some ignition parts are no longer available for an engine that old.

 

[ryan_289]

Re: nissan 9.9 no power.

I knew that some of the parts were no longer available. I was just wanting to see if I could get it going without much expense. The motor looks real clean and doesnt appear to have had much use.

 

[ryan_289]

Re: nissan 9.9 no power.

I searched the manuals on the marshall public library. They dont have this outboard. What are some of the things I can check?

 

[TOHATSU GURU]

Re: nissan 9.9 no power.

The ignition values, troubleshoot the fuel system and troubleshoot the mechanical side...You need a manual for the values and procedures.

 

[ryan_289]

Re: nissan 9.9 no power.

put a compression gauge on it this afternoon, 145 on both cylinders. I may have found the issue, I was squeezing the primer bulb on the line and heard air hissing inside the tank. The pickup tube was leaking air up top. Im thinking that it may have been sucking air when I was getting on the throttle? I put a new line on it and will run it later this week.

 

[pvanv]

Re: nissan 9.9 no power.

You may have found it !

 

[ryan_289]

Re: nissan 9.9 no power.

Well thats not the issue. In neutral it runs great and will rev up fine too. In gear pushing the boat it just sort of stutters at higher rmp. Once we were running at full throttle and it picked up and ran fine for a minute, then back to lower rms with the stutter.

 

[Sea Rider]

Re: nissan 9.9 no power.

Seems you have a bad engine gasket that's letting small water droplets pass into cumbustion chamber producing unwanted stutters, sputters at load at higher rpm, this tech issue has become popular these days with many Iboats boaters as well, you will not find this symptom listed on any service manual related to a head gasket leaking failure. Head gaskets are not eternal, wores much faster as nobody re torques their engine's head from time to time which is mandatory to perform. By your description, you are experimenting near same case :

http://forums.iboats.com/showthread.php?t=542292

Happy Boating

 

[TOHATSU GURU]

Re: nissan 9.9 no power.

There is no indication of a bad head gasket and there is no substitute for troubleshooting. Random replacement of parts is not cost effective.

 

[ryan_289]

Re: nissan 9.9 no power.

The stutter only happens it the water under load. Never at home on muffs. Im not sure if im going to go much further with this motor. I dont have any money in it since I sold the boat for what I paid for the whole rig. I was planning on keeping the 9.9 since it had electric start untill I saw the parts availability. Its a shame too as nice as the outboard looks, I dont think it has many hours at all on it. I hate to spend the money on a manual just to end up finding out that the part I need is obsolete. If anyone has some troubleshooting values for me that would be great, otherwise it may be time to just part it out.

 

[Sea Rider]

Re: nissan 9.9 no power.

If you already have troubleshoot all fuel, electrical related parts and are responding ok, if engines runs ok at different throttle range on gear and on mufs without load, HG is the main cause.

For what it cost to buy and replace a head gasket $20-25, if mechanical inclined and the inmediate benefits it will surrender. If boater wants to buy service manual and troubleshoot the whole engine waisting precious boating time and effort, be my guest, have had same symptoms as described on my 18 horse and a new head gasket and overall internal combustion chamber inmaculate clean out made all the difference as other boaters having same issues have lately found.

As stated before there's no indication for a head gasket failure on the general troubleshooting chart. Will need to open head, clean, re torque and go for a wot spin. The tech dept that wrote the service manual seems to belive that head gasket are eternal, and that ain't so. Runing an engine on muffs out of water than doing so at sea and under load are 2 different stories. Slutter, hesitation performance is mostly due to the fact that gasket has lost it's 100% sealing capabilities between crankcase and head. Save the cost of a service manual and change head gasket and base gasket as well. Before partying that nice electrical start engine, check to see if 9.9 D2 gaskets are compatible with 9.9 B2 model. Will have engine operational for years to come... Check pics for understanding.

Newer 9.9 D2 model needed gaskets are :
351010050M (Head Gasket)
350013031M ( Engine Base)

Happy Boating