Stalls going to WOT - 78 Evinrude 175

[wrj9892]

Took the boat out again. Had a lot of problems getting it started. We had almost run out of gas the last time we were out. Finally had to prime it probably 20 times before it finally started. We have a 1978 Evinrude 175 VRO outboard. Primer bulb never did get hard. Ran great until we decided to stop and fish for a while. Fished for about an hour then started up. Started just fine but wouldn't go past 1500 rpm's. Finally put it in neutral and used the warm up lever to rev it up for a couple of minutes. Then it took off just fine and ran wide open. Any ideas on what might be causing this problem?

 

[wilde1j]

Re: Stalls going to WOT - 78 Evinrude 175

Bad primer bulb, air leak in fuel line, tank pickup screen clogged, engine fuel filter clogged, cracked fuel line, non return valve stuck (this is usually first fitting at tank if permanent tank), etc.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

Thanks for the info Jim. I'm completely new to boating, so excuse the ignorance, but where do I find the pickup screen?

 

[revertmastec]

Re: Stalls going to WOT - 78 Evinrude 175

Look at the bottom of the hose going into your fuel tank. There should be a screen at the end that prevents anything large from entering the fuel system. If this gets clogged you will have problems getting the correct amount of fuel.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

Another part of the question is what should the rpm's be at full throttle? The tach said it was running at 4600 rpm's and we were going about 37-38 mph.

 

[wilde1j]

Re: Stalls going to WOT - 78 Evinrude 175

Once you're sure the motor is running right, 5800 RPM WOT with typical load. 4600 is way too low. An inch of prop pitch reduction will gain ~ 150 to 250 RPM, so you may have to lose a fair amount of pitch. But be sure motor is developing max power 1st.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

In checking the fuel line for leaks, I noticed that the prior owner, who rebuilt the motor, used plastic quick tie straps to clamp the hoses to the fuel pumps, the t-connectors and the carburetors. This doesn't seem like a very good way of connecting them to get a tight seal. Before I change all the clamps, I was wondering if you agree this could be part of the problem.

 

[wilde1j]

Re: Stalls going to WOT - 78 Evinrude 175

I would not use tie wraps for fuel clamps. Use either SS worm drive clamps or the OEM black nylon kind OMC uses for fuel/oil lines. Given the symptoms, this is a cheap thing to try.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

In replacing the fuel lines to the fuel pumps, I noticed that one of the pump covers had a metal screen on it and the other one didn't. What is the purpose for the screen and should both covers have the screen on them?

 

[wilde1j]

Re: Stalls going to WOT - 78 Evinrude 175

Not sure what you're talking about. Your motor has more than one VRO pump? The VRO pumps both oil and fuel. Typically one per motor.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

I just received the service manual and now I'm confused too. The cover on the motor says 175 VRO. However, in comparing the motor to the manual I'm not so sure it is VRO. The manual says that VRO didn't come out until the early 80's. The prior owner stated that this is a 1978 motor. It does have two fuel pump filters. The covers say filter on them and they match the drawings in the manual (round cover with a hose connection on it). I'll have to get the numbers off the motor and verify its year.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

Replaced all the fuel lines and primer bulb. Starts up great now. Took it out on the lake and still had the same power loss. Got away from the dock and put it in forward. Got up to 15oo rpm's and it started stalling again. After a few minutes of revving it up in neutral finally got up to full throttle. Ran around the lake for a while and then decided to go back to the dock and pickup a tube. Never could get it back to full throttle again.<br /><br />Next morning, used the service manual and found that the choke linkages and throttle linkage had been reversed. Changed then around and checked the throttle settings. Made some adjustments but haven't been back out yet. Don't know if this will make any difference.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

Also, decided this isn't a VRO motor based on the pictures of the VRO.

 

[wrj9892]

Re: Stalls going to WOT - 78 Evinrude 175

Have learned this is an 1979 Evinrude V6 150 hp. Took the boat out this weekend. After warming it up, we got up to full speed. However, if we let it set for 10 minutes, it would stall at 1500 rpms. When we got back to shore, I took the cover off the carburetors and notice oil dripping from the bottom of the cover. Anyone have any thoughts?