2003 Honda 75 4 stroke

[grouperbob]

With choke half way out engine will run up to full speed. Run for 5 mins then console alarm goes off and engine shuts down. New water pump and impeller, new fuel pumps, carbs rebuilt with kits and gaskets for intake manifold etc, new thermostat. Cleaned lower water poppet and reinstalled. Pisses like a race horse. Felt engine after shut down and did not feel hot...no steam from visual water stream. I was back by the motor during test run and could not see the console so any lights are unknown. Any advice would be great. Thanks in advance

 

[ahicks]

My first move would be to see if it's the low oil pressure warning you're hearing. Check that sending unit.

I read somewhere where they were talking about the oil pressure port becoming blocked off too, though I don't remember how they check it, or what they did to clear it.

Bigger point here is that this could be an oil pressure issue as easily as a temp related issue. Either will set that alarm off.

 

[grouperbob]

Will do.Thanks for the advice. I will post what I find.

 

[grouperbob]

Went for a test run. Engine starts and idles nice. The second I try to throttle up the engine dies. So was not able to run it up for alarm. I believe problem now...is the diaphragm assy. From what I can tell it is a acceleration pump. As you open the throttle it pushes air into a fuel rail and gives the carbs more fuel. Part# 16240-ZW0- L02. If I can get the part tomorrow The test run will be Saturday.

 

[grouperbob]

Well...according to a Honda mechanic the diaphragm assembly only keeps the engine from stalling when throttle is pulled back from a high speed.

 

[ahicks]

The stuff I've worked on is always older, so when you said "accelerator pump" I dismissed it figuring I just hadn't worked on anything new enough to see that. I know what you are talking about now though, and the mechanic is right.

I think you're talking about 2 unrelated issues. The alarm going off, and the lack of acceleration, and they are very likely not associated with each other. My best guess is that if you can't get the engine to take gas, it's going lean. It's either related to fuel delivery to the fuel pump/carbs, or the carbs themselves.

You have 4 carbs, so the likelihood of all 4 having the same lean issue causing the engine to die is slim. If it were the carbs, 3 of the 4 would try to go, with the 4th one out on break, causing a bad miss on acceleration - not a total shut down.

That leaves the most likely culprit somewhere in the fuel delivery systems - with clogged filters the most likely suspect, followed by fuel lines (collapsing internally).

Can't be more helpful on the alarm issue other than what I gave you earlier.