Johnnyrude running bad... HELP! OMC GURU'S!

[O/B Dude]

A friend has an 87 115 Johnson V-4 with VRO. He bought it new in 88 and has a manual for it. Its mounted on a 16' sea sprite. The motor wouldnt run well after sitting for 2 years. He rebuilt the carbs and replaced the water pump impeller. (New gas also) He replaced the VRO pump and I think the fuel pump diaphram. Ran ok but wasnt getting good top rpm. He found some spark problem. Someone suggested he swap powerpacks to see if a spark problem moved with the packs. It did, so he replaced 1 of them. It ran great but after running for a while it wet fowls the plugs and he can only get 30 mph out of it untill plugs are cleaned or replaced. Normally runs in the 50's. Says the plugs are wet and oily. He has cranked the motor with all the sparkplugs removed and without pulling the kill switch or grounding the plugs. I just told him not to do that anymore as he may have fried something. I suggested he ohm the stator and check the enrichener to see if it is dribbling fuel. Other than that, I dont know much about OMC's. I told him to paint the motor black but he refused. :rolleyes: Any ideas or suggestions from you JohnnyRude guys? :D
Thanks in advance.

O/B Dude

[RRRevinrude]

check the fuel primer---may be in wrong position or blown.....little red arrow has to be in right clock position or it will choke itself all the time

[O/B Dude]

Thanks for the reply. I suggested he check it but the thing that makes me believe its somethong other than the primer is that the motor idles fine. Anyone else have any ideas? My buddy lives way across country so I cant just drop by and start testing things.

[O/B Dude]

ttt

[Greg Moss]

If it was the primer it would flood at idle. You can check it easy with the motor idling on the hose pull the top primer hose off the top carb and see if fuel is running out of it. If not the primer is ok you can also push the key in with the hose off and the motor running to see if it squirts fuel. that is the easiest way to check the primer circuit. Now to how come it ain't running right. If it is a 87 115 it doesn't have any SLOW curcuit so It would have a more standard ignition system, I would think it to be the stator heating up if it does it after a while of running. OHm the stator out and see if it is in specs. If it checks out the flame arrestor for the fuel pump may be full of carbon and restricting the pulses for the VRO pump. It may be restricting the fuel flow at high rpms.

[Bill Gohr]

does the motor runs OK at an idle for a long time and doesn't foul the plugs? If so, you mentioned he rebuilt the carbs and the VRO assy. Remove the top primer hose and the pulse hose to the block. Squeeze the primer bulb and see if fuel comes out of either. If not reinstall the hoses. You said it ran OK for a while. It could be he forgot to tighten the high speed jets, that would make it foul the plugs when running WOT and would run OK for a while. Take the carbs back apart, check the jets, this also has plastic float bowls, when you put them together you can't over tighten them, if you do it will cause running problems, when they are apart flat plate the bowls on sandpaper, most likely they're warped. Don't try to tighten the snot out of them they're plastic.

Let me know what you find

[O/B Dude]

Thanks for the reply's! I will pass this info on. By the way, the motor is a 90, not a 115 as I had indicated. My mistake.

Thanks again Greg and Bill.

Sean ("Mercury" O/B Dude)

[racer]

A very common and often over looked problem on the 87 and newer v4 cross is the cam follower for the ignition timing (GOHR were you sleeping), it is a two part plastic roller that often looses the outer clear part, thus reducing ignition timing and leaving the motor rich. It is located on the stb side and fits between the arc lever on the linkage.

[Greg Moss]

He said it runs right for awhile then starts acting up. I had thought of that but the running good for awhile part mad me think of different things. I have some vinyll tubing that i press over the black part of those rollers that last alot longer than the stuff from the factory.