Nissana 40 hp = Mystery of the year....NEED HELP!!

[calm like a bomb]

1988 Nissan 40 hp 2 cylinder fuel problem.<br />Went fishing for two days and the boat ran fine.<br />It abruptly died out of the blue under about 20 percent throttle load as if I had turned the ignition off or pulled the kill switch.<br /> It refuses to start or fire..had to be towed back to the ramp.<br /> Plugs were not fouled and after getting boat back on trailer the ignition seems to be providing plenty of fire to both cylinders.<br /> The compression is fine on both cylinders also.<br />It just refuses to start.The cylinders are getting plenty of fuel..possibly too much.<br /> Cleaned filters and found a small amount of fine particles in fuel.I am sure this does not help but should not prevent the engine from even coming close to starting.It has not coughed,sputtered or given the slightest indication that it will start.Tried new plugs,fuel flow is good but it refuses to even fire at all.Plugs get wet with fresh fuel in short order..almost seems like it is getting too much fuel at times.<br /> Still does not explain why..even as a last resort when I sprayed enough starter fluid directly into the throat of the carb to start the Space Shuttle....it STILL WILL NOT FIRE!?Fresh plugs and fresh gas also are being used.<br /> Removed carb and cleaned,no help..does this engine have Reed Valves that could have malfunctioned?<br /> After removing the carb I can see what appears to be reed valves behind the carbs.<br /> My only other guess would be that it possibly jumped time..is this possible?<br /> As stated earlier it is getting strong blue fire from both plugs,so I don't really think it jumped time.It has gotten me whipped right now. <br /> Please help if anyone has an idea what is causing this condition.THANKS!!

 

[TOHATSU GURU]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

It does have reeds, but I would take the carb back apart and let it soak in carb cleaner for at least five hours. Then try it again.

 

[steelespike]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

It is possible it may have damaged the flywheel key if you hit something or the nut wasnt properly tightened.I would try a dry carb with no gas hooked up.Carefully spray fuel mix into the carb and crank.Dont use starter fluid as it washes away lubrication.If it refuses to fire<br />check the flywheel key.

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Elvin,<br /> The carb was removed,disassembled and gone over with a fine tooth comb.All of the parts were cleaned individually with carb cleaner and all the jets serviced,the float was adjusted a tiny bit to let it sit perfectly level..I figured that would be more thorough than just soaking it and letting all of the loose particles cause me another problem later.There was a small amount of old varnish dried in the bottom of the bowl but overall it looked pretty good.<br /> Everything was reassembled and I tried it again..same exact result.I have worked on quite a few outboards over the years with good results but this one has me <br /> From what I have seen,there is no reason I see the engine would have died abruptly like it did under little to no load after running fine and now it refuses to start or even show the smallest sign that it may fire.I am just about ready to take a fire-ax to it and purchase something else. <br /> I doubt I will ever trust this engine again.I'm that aggravated with it.

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Spike,<br /> I may have to try the fuel mixture in a dry carb..I know that ether leans out the mixture but really saw no other way to fire this engine after the problems it has given me over the last two days.<br /> The flywheel appears to be OK..I did not strike anything with it and am baffled how it died for no reason and refuses to fire.<br /> If I am getting strong fire from both plug wires,how can the flywheel be an issue?It appears to still be in time if the strong fire from both plug wires is taken into consideration.How can I check the timing and the flywheel key? <br /> Thanks In Advance

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Spike,<br /> If I have to resort to the fuel mixture spray method...what is the best way to do it?<br /> Does it require a small amount or a pretty fair spray volume? Thanks Again

 

[rayjay]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

It does have reeds but the chances of breaking off one in both cyls at the same time is about zero. Often with a broke reed the motor will run at idle but go dead when the throttle is cracked.<br /><br />My guess is the ign pickup coil or the powerpack [ aka cdi box ]. Fire, just not at the right time. Check to see if the flywheel nut is tight. If it is then the flywheel key is probably not sheared. Also you could remove the #1 plug, look down the hole and position the piston at tdc then verify that the flywheel tdc mark is aligned correctly. <br /><br />Gotta have compression, combustible fuel mixture and fire at the right time. Basic I know but if you let the problems get personal then they can drive you to the insane asylum <br /><br />The basic thing here is that whatever the problem is, it affects both cyls equally. With twin carbs usually only one cyl acts up if you have a carb problem [ excepting water in the gas ]. That is why I think it is the ignition. I have seen lots of engines with plenty of spark just at the wrong time. CDI box or pickup coils . Pick up coil is easy to test with a good multi meter. CDI box really requires just swapping in a known good unit.

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

rayjay..I appreciate the advice.It's starting to look like it probably is electrical.The way it abruptly shut down acted like I cut it off at the key or pulled the killswitch off.<br /> My main question is where the timing marks are on the flywheel and where they need to line up.I do not have an owners manual yet for this engine.Also I'm not sure where the ignition pickup coil is..under the flywheel would be my guess.? Is there a test to see if it is bad? <br /> As far as a multimeter test..what do I need to look for when testing to see if the CDI unit is shot?Best procedure to keep from getting zapped.<br /> I appreciate the help more than you know.THANKS!

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Duh,<br /> rayjay..I see now that a swap test is required to test the CDI box.(Known good unit)<br /> I can only check the ignition pickup coil with a multimeter.Still not sure what the procedure is or what I need to look for though as far as the readings go.I can tell already that I need an owners manual.That's usually the first thing I do when I get an engine..hoping I don't have to use it enough to get it good and greasy.

 

[rayjay]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Yeah, you need a service manual. There is a simple resistence reading for the pick up coil and a check to make sure it isn't shorted to ground. There may be some resistence checks for the CDI box or the manual may say to hook it up to some bazillion dollar cdi box checker but often manuals just say "check out with known good unit".<br /><br />That is one of the few problems with the Tohatsu's. Not likely to find used bits easily. I used to do ignition mods on race cars and have always wanted to try and convert a dead outboard ign to a GM HEI module. the only real downside would be that it would be a battery powered ign. Without a batt you no go.

 

[calm like a bomb]

Re: Nissana 40 hp = Mystery of the year....NEED HELP!!

Does anyone know where the ignition pickup coil is located on the Nissan 40hp two cylinder and the best way to get to it ?