1978 85hp power surge/ dry plugs HELP

[wetplug]

I have bought my first boat, its a 1979' glastron with an 1978 85hp evinrude on the back. Since i took it out the first time i knew it wasn't running right. I know my boat goes faster, i've had it at 40mph on wide open throttle for a few seconds and then it bogged down and now i can only get 28 mph. When i'm going at WOT once in a while i would get like a power surge for a fraction of a second like it wants to pick up speed but is maybe being starved. I'm suspecting its the fuel pump because i have one wet plug and all the rest are bone dry like they are starved. However i don't know how to test these fuel pumps. Someone told me that if you take the fuel out line off and pump your bulb and the gas just sprays out then it has a bad diaphragm, would this be correct because when i do this the gas does just spray out?

Things i've done:
Carb rebuild kit
Cleaned jets
Ohmed coils
replaced fuel lines
tested spark

Any ideas please and thanks in advance.

 

[Daviet]

Re: 1978 85hp power surge/ dry plugs HELP

If you remove the fuel out line and squeeze the primer bulb gas should come out, thats how you prime the carbs.
If you remove the fuel pump and squeeze the primer bulb and fuel comes out of the hole in the back where it mounts to the block, then you have a defective diaphram.
Which spark plug is wet, the cylinder that pulses the fuel pump?
If you squeeze the primer bulb while the problem occours and it helps, you probably have a defective fuel pump.

 

[emdsapmgr]

Re: 1978 85hp power surge/ dry plugs HELP

It is possible that the one plug is wet because it is not firing. Check it for spark. Likely you are dropping one cylinder when it's running.

 

[wetplug]

Re: 1978 85hp power surge/ dry plugs HELP

I had checked the spark before. I swapped coils to see if the wet plug followed the coil. I went and brought the boat out to test it and now today i'm not getting spark on two plugs on opposite sides and i noticed one of the plug wires is leaking the spark through the insulation because i got shocked by it when i was holding the wire to check the spark. Is it possible that the one that was leaking spark was arcing on the block and ruined the other coils? Is resistance testing a good enough way to test the coils?

 

[wetplug]

Re: 1978 85hp power surge/ dry plugs HELP

any suggestions please???

 

[whalerfreak22]

Re: 1978 85hp power surge/ dry plugs HELP

If you are leaking spark replace that coil!also a bad fuel pump has nothing to do with 1 cylinder.I had a 1984 115 Johnson that always had spark problems it was always the coil.any other questions?

 

[whalerfreak22]

Re: 1978 85hp power surge/ dry plugs HELP

You are probably dropping a cyl under load you should buy an inductive timing light to see if your getting spark at high speed.

 

[whalerfreak22]

Re: 1978 85hp power surge/ dry plugs HELP

Weak coils tend to fail when they get up to normal operating temperature.

 

[emdsapmgr]

Re: 1978 85hp power surge/ dry plugs HELP

It is very possible for old wires to short to ground when running. It's possible for you to see arcing if you run it outdoors after dark. When the engine was new it had a number of small clamp-type brackets which were rubber (insulated) coated to space the coil wires away from the block (ground.) Also, check the bottom two wires, as they are in close proximity to the two bottom latches on the cowling. They may be shorting to ground at those two latches when the cowling is in place.

 

[rolco31]

Re: 1978 85hp power surge/ dry plugs HELP

What did you find out on your motor? I'm having a similar problem with my '69 85hp evinrude.