65Hp Evinrude bogging at WOT

[tr918]

I have a 65Hp 1972 Evinrude model#65273. Last season she ran great in the begining. End of season it would start right up and idle fine. When I increased the throttle to WOT the engine would bog down and boat would not move faster than idle speed. Checked compression got 110 - 120psi on all 3 cylinders. Replaced plugs new champion L77J4 gapped at .040. No air leaks in fuel bulb and lines all replaced prior to last season. Fuel pump is only 3 seasons old and is leak free. When troubleshotting I found my ignition coils were cracked. I read on another post in here that that might be the problem. All three coils were replaced. I took it down to the water to test it this weekend and it still bogs. I looked in side the front of the plastic plugs on the carbs while it was running I can see the fuel misting into the openings. I am not sure it is the carbs. Could it be the power pack or am I wrong on my assumption of the carbs? If it could be the power pack is there a way to test it without the Evinrude neon tester? - sorry for the long post. Thanks

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

When it bogs have someone use very well insulated pliers to pull the plugs one at a time. If the engine dies or runs rougher that cylinder is firing. If there is no change then you have lost that one. Could be the powerpack or a bad ground on it. Clean the connections good first.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

I thought if I have lost a cylinder it should idle rough? And my compression would be low in one of the three cylinders,right? Can I do the plug wire test while it is idling in the driveway with the water muffs?

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

Most the time people don't realize that they have lost a cylinder because it will idle fine. You can try doing it in the driveway. The only reason I suggested doing it on the water is that it may be breaking down under a load. Do not rev this engine in neutral on muffs.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Thanks. I know not to rev it on muffs. It is only a 10 minute drive to the Ohio river, but I don't have the availability of a second person until the weekend. What do you mean by lost a cylinder? Are you reffering to spark? Compression on all three cylinders checked good.

 

[jason389]

Re: 65Hp Evinrude bogging at WOT

Lost cylinder generally just means it isn't making power. Even if one of the cylinders isn't firing or getting fuel, it still may still have good compression, thereby rendering it impotent. Also, the motor will usually idle on two or even 1 cylinder, under no load. I had this same problem, and one of the jets in #2 carb was plugged. The cylinder just wasn't getting enough fuel. Cleaned all 3 carbs, no more bogging.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Thanks. I had originally thought the problem was electrical. I have checked everything short of using a s80/m80 neon tester to check powerpack and charge coil output. It sounds like my problem lies in the carbs. Is there a way to test whether the carbs are sending enough fuel? I was hoping I did not have to rebuild carbs. I am new to marine engines and have never rebuilt a carb. Are they hard to remove from the motor and is it hard to put them back correctly. I do not want to screw anything up worse than it already is.

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

Carb rebuilds are pretty simple if you take your time and get a good OEM manual to guide you. Make sure you go to section on link n sync after the rebuild and follow those steps. I would recheck the spark to eliminate your powerpack before I tore into the carbs. Simple test and costs nothing.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Do not have the OEM manual. Just the Clymer manual. I do not have a neon tester to test the power pack, and charge coils. Can this be done with a voltmeter? I will check spark again. But I have been consistantly able to get it to jump half an inch. I did a resistance check of the sensor coils and the charge coils last night. Sensor coils checked ok. Charge coils read ~830 ohms. Clymer manual says normal is 870 to 930 ohms. Does this sound right? Should I replace the charge coils and stator assy? Can I check the output of the charge coils with a voltmeter?

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

If you have bright blue spark that jumps the 7/16 to 1/2' when it bogs then they are ok. Must be in the carbs. I was just hoping that you checked it when the symptoms showed up. A lot of them will do fine at idle or on muffs but not under a load.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Have not checked it when it bogs. Next opportunity I get to take it down to the river I will check. Thanks

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

I had read elsewhere in this forum that there is a way to test if the carbs need rebuilt. The thread stated that you could take a spray bottle with premix (gas & oil) and spray it into the carbs when it was bogging down. If that cylinder picked up and ran better that carb needed rebuilt. If it did not change then the problem is not the carbs. Is this correct?

 

[Marauderk]

Re: 65Hp Evinrude bogging at WOT

Yes i have used a small bottle of premix to spray in to make sure i was getting gas thru a carb works well

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Took the boat and tested it this weekend. I tried the bottle of premix and there was no change in the bogging. I actually flooded it a couple of times. I checked the spark at WOT. It jumped 1/2". When I went to check the spark I noticed a black film on the insulator of the plug. Started the engine and watched the plugs. The spark was jumping from under the plug wire boot to the outside of the plug. What causes this? I removed the plug and it wasn't fouled. The ignition coils are new. They are OMC coils and I assembled them per the included directions. I have Champion L77JC4 plugs in the motor, should I be using a different plug? Any suggestions? Thanks

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

Did you have to assemble these coils yourself or were the plug wires already seated in the coils. If you had to do them yourself it is tough to get them exactly centered on the pin in the coil. I had to literally screw them on with a pair of needlenose pliers to seat them. Measure the distance to the bottom of the pin then mark your plug wire that distance. When you remove the wire to do this make sure that the pin was seated in the center of the wire. Then make sure that you get the wiren installed all the way up to your mark. You may have a bad connection at the plug end also. Make sure that the little coil that goes over the plug is dead center in the wire and not turned sideways so it won't go over the plug properly. You plug might be fouled by now from not getting spark and you probably want to change it. Your problem lies in this area. Swap the coils and see if the problem follows. If it does then the problem is a connection in that coil.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Thanks for the tip and all the help. I did have to assemble the coils myself. I had wondered about the connection to the coil. I will check this tonight. I was unhappy with the quality of the wire hardware that came with the kit. The little coil that went over the plug seemed a little flimsy. I planned on picking up new plugs on the way home this afternoon. I don't think swapping the coils will change anything. All three plugs/wires were doing the same thing. It looks like my problem lies in the wires. Thanks again.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

Fireman57, Thanks for your help. I fixed the spark problem. It was a bad connection at the spark plug. I picked up the replacement plug boot terminal from OMC. It fit more snug than the ones that came with the OMC coils. I took the boat out and was able to get the bow in the air but was not able to achieve full speed and make the boat plane. At WOT it still sounded like it was missing a bit. <br /><br />Is there a way to test the power pack out put with out a s80/m80 neon tester? Could my problem be the power pack?<br /><br />I checked the resistance the sensor coils and the charge coils again last night. Sensor coils checked ok. Charge coils read ~830 ohms. Clymer manual says normal is 870 to 930 ohms. Resistance is lower than the specification. Do I need to replace the Charge coils?

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

If it were me I would have a friend that I no longer want pull the wires with insulated pliers one at a time while you are WOT and the problem shows up. I wouldn't go to the powerpack this quick. If you miss get's worse when you pull a plug wire then that one is okay. When it doesn't change then you know you are not getting spark to that one. Recheck the connections for corrosion, misfit wire, etc... If you are positive that all is well at that point then you can spend the big dollars on a pack. Are you able to swap coils and see if the problem follows with the spark? If it follows then the problem in the coil connection or the boot or just a plain bad wire. As far as testing the pack do a search at the top of the page. Sounds like you are close to what it should be and it might just be a bad connection.

 

[tr918]

Re: 65Hp Evinrude bogging at WOT

I did swap the coils and there was no change. Before I put new coils on it I could not get the bow in the air. My old coils were cracked, I thought that was the problem. It appears the coils were only part of the problem. The spark jumping from under the plug wire boot to the outside of the plug was a result of incorrect assy of the coils. Thanks to your help I have fixed my own mistakes with the coils. I can get more power out of it than I did before. Is there anything else I can try before just throwing money and parts at it?

 

[fireman57]

Re: 65Hp Evinrude bogging at WOT

When you say there is no change are you losing spark to the same plug or does it move to a different plug? Just because it is still running the same (crappy) doesn't mean that it is still not losing spark to a plug.