Need Help for Evinrude XP. Stalling on Load

[evinrudexp]

Hi all! I have been pulling my hair trying to figure out what's wrong with my 150 hp 1988 Evinrude xp vro. On sat I was running it in Lake Havasu and it ran like a charm all day. Sun morning I took it out again. The only thing different that I did was add tc3 oil to the oil tank. It ran alright for a few minutes then lost power when it was in gear. In neutral it runs great. When I put it in forward gear it would start to lose power. Sometimes I would leave it in the full throttle position as it barely moved 10 mph and then all of the sudden it would get its full power and take off...and then lose power. I changed the spark plugs (they were all oily) and checked the spark to all 6 cylinders...all seemed good. The primer bulb was also pretty firm. What can this be? Is it the carbs, fuel pump, or power pack? If so then why is it fine in neutral? Please help!!! Thanks, Nick

 

[ezeke]

Re: Need Help for Evinrude XP. Stalling on Load

Check carefully for air leaks in the fuel line all the way to the VRO pump connection.

 

[Silvertip]

Re: Need Help for Evinrude XP. Stalling on Load

An engine running on half its cylinders will reve freely in neutral -- you simply do not feel the roughness or lack of power. When the engine loses power, squeeze the primer bulb a couple of times. If the engine comes to life, its a fuel delivery problem (debris in the tank clogging the pickup, possible air leaks at fittings, bad fuel pump, debris in carbs, etc.).

 

[fishweed]

Re: Need Help for Evinrude XP. Stalling on Load

Welcome to Iboats!!!<br />The members above have helped allot of poeple, including me. Check the things that they have mentioned, but also do a spark test. Each plug should jump a 7/16" gap with a health snap.

 

[evinrudexp]

Re: Need Help for Evinrude XP. Stalling on Load

Thanks for your replies. I can tell this is a great forum. The primer bulb was pretty firm and I did squeeze it but nothing changed. When I checked the spark it did jump a 7/16 gap. I'm lost here...what steps should I take???

 

[reeldutch]

Re: Need Help for Evinrude XP. Stalling on Load

i would check for contaminated fuel.<br /><br />did you fill the tank up on saturday?<br /><br />check fuel filter.<br /><br />clogged vent on tank?

 

[emdsapmgr]

Re: Need Help for Evinrude XP. Stalling on Load

If you are handy and have a timing light: When it starts to drop a cylinder, remove the cowling and hook up a timing light. Check each plug wire for constant, strong flashes. See what you get.

 

[evinrudexp]

Re: Need Help for Evinrude XP. Stalling on Load

Originally posted by reeldutch:<br /> i would check for contaminated fuel.<br /><br />did you fill the tank up on saturday?<br /><br />check fuel filter.<br /><br />clogged vent on tank?

Yes the fuel was fresh out of the pump. I filled up on Sat when it ran great and again on Sun when it ran poorly. I replaced the fuel filter when I replaced the plugs. The clogged vent is an idea. I think I'm going to buy a one gallon tank with a new primer and hook it up straight to the fuel pump. This should eliminate any problems from the fuel pump back to the fuel tank.<br /><br />How can I check if the fuel pump works under load (when accelerating in forward gear)?

 

[OBJ]

Re: Need Help for Evinrude XP. Stalling on Load

As sudden as this problem came about, I think I would look toward the ignition system as the problem. You have two power packs on the engine and one can go out while the other is still OK. This would cause the problem your having.<br /><br />Check your spark on both banks of cylinders without the engine running and then check them again with the engine running and the block up to temp. If needed, put the boat on the water and put it in gear and check the spark as emdsapmgr suggested.

 

[evinrudexp]

Re: Need Help for Evinrude XP. Stalling on Load

Originally posted by OBJ:<br /> As sudden as this problem came about, I think I would look toward the ignition system as the problem. You have two power packs on the engine and one can go out while the other is still OK. This would cause the problem your having.<br /><br />Check your spark on both banks of cylinders without the engine running and then check them again with the engine running and the block up to temp. If needed, put the boat on the water and put it in gear and check the spark as emdsapmgr suggested.

Would a bad power pack cause the motor to stall in gear but then all of the sudden take-off?<br /><br />I'll give it a shot!

 

[fishweed]

Re: Need Help for Evinrude XP. Stalling on Load

I had very similar symptoms with my motor late last summer. It started and idled fine, but would start to mis on one cylinder at mid range. The problem got worse as the motor heater up. When pushed to full throttle, it took off like it found another gear. I just new it was a fuel problem and chased it all winter. I finally tested each spark plug wire with an OHM meter. I would bend and twist each wire while testing and found one wire that had a rusted off clip and another that was going bad.<br />I am not saying this is your problem, but be sure to test obvoius and simple things before throwing money at the problem.