2002, I think, Nissan NS25C2 not cranking

[crbarwick]

I am currently working on a Nissan 25 for a friend of mine. I have cleaned the carbs, replaced the fuel lines and spark plugs. After replacing all of that, the motor would crank but only at high rpms and then die out after about 10secs. Checked the compression and have 120psi on both cylinders. Motor will not crank now. It acts like it wants to but just won’t do it. I am at a lost right now. Any help would be greatly appreciated.

 

[Sea Rider]

Welcome to IBoats,

If all mechanical related is spotless, troubleshoot all the electricals components such as Exciter, CDI and Ignition Coil, being a 19 year oldie any of those electrical components could have failed already, heats up, shorts and fails. Start by checking if each spark plug when grounded fires strong when pulling the rope hard...

Happy Boating​

 

[crbarwick]

Welcome to IBoats,

If all mechanical related is spotless, troubleshoot all the electricals components such as Exciter, CDI and Ignition Coil, being a 19 year oldie any of those electrical components could have failed already, heats up, shorts and fails. Start by checking if each spark plug when grounded fires strong when pulling the rope hard...

Happy Boating​

Is there a website to tell me how to test the cdi box with a fluke meter? I just checked the exciter and it showing within tolerance. The ignition coil shows within tolerance to ground but shows an open on both spark plug leads. Just wanting to test the cdi so if I need to order one I can do so all at once

 

[pvanv]

Of course it's an old obsolete motor, but the Factory service manual should help you out. Not unusual to read nearly infinite ohms on the secondary of the coil.

 

[crbarwick]

I’ve ordered a new ignition coil should be here Friday. How do I check the timing on this motor, just to make sure that it is set correctly.

 

[pvanv]

Check link and sync as detailed in the FSM

 

[crbarwick]

This is this timing with the motor in forward gear and throttle wide open.

 

[Sea Rider]

When at full throttle, does the butterfly sits opened fully horizontal at 180 deg ? If so with current 25 deg time advanced setting that motor has been upgraded to the 30 HP version which was the way to go. To be a fully operational 30 HP need to look if the carb's restricted gasket has been swapped for the full opened un restricted gasket, more fuel intake along more time advance needs more air inside the combustion chamber for top combustion.

Which type of boat, lenght is being powered with said motor, which is the current prop pitch number stamped on the prop body or blade ?

Happy Boating​