1973 johnson 6hp no power at full speed

[johnevans]

It starts fine but when full throttle I get no more speed but I back off on throttle it spits and sputters but I also noticed that when I pull on the spark plug wire it picks up speed at full throttle why is this

 

[interalian]

Pulling on the spark plug wire must be completing a circuit that's broken or moving the cable away from something it's shorting to. Sounds like the solution is new spark plug wires. Either that or they're the type that screw into the coil and are loose. If so, cut a half inch off and re-screw the cable into the coil.

 

[johnevans]

Well I will check to see if it is a screw in type but I also noticed that the armature plat would move with it and it ran better I thought it could be a timing issue but I've checked the wire before hand they seem to be good and I also moved them in different directions and no difference unless it was moving that plate I will try the shorting of wire when I get off hope that will get it thanks

 

[Vic.S]

Well I will check to see if it is a screw in type but I also noticed that the armature plat would move with it and it ran better I thought it could be a timing issue but I've checked the wire before hand they seem to be good and I also moved them in different directions and no difference unless it was moving that plate I will try the shorting of wire when I get off hope that will get it thanks

This. I think, is the clue to where at least part of the problem probably lies.

Check that when you turn the throttle control to full WOT position that the carb butterfly valve is opening fully.

I suspect you will find it is not and there is a problem somewhere in the linkages etc between the tiller control and the armature plate.

First place Id look is the knuckle joint where the tiller pivots. It is possible I beleive for the gears there to become a tooth out in their engagement

between # 68 and 75 and also between #69 and 73 in thie diagram here http://www.crowleymarine.com/johnson...arts/42345.cfm

Also check the carb cam follower operation against the armature plate cam.

I dont know what "sync and link" marks there are on this engine but this manual covers your engine http://boatinfo.no/lib/evinrude/manu...inrude.html#/0

 

[johnevans]

I've read about the knuckle maybe off before but it look tight but when I get up I will look again and for what I have seen there is no adjustment on the cam follower and thank y'all so much for the information

 

[racerone]

Run with a timing light hooked up and see what happens to the sparking.---Test both leads.

 

[johnevans]

Yea I have yet to find how to hook up a timing light to it but I did look at the tiller handle and it appears to have timing marks on the knuckle on both sides and if it does it's out of time some but I have just got to work if it's a slow night I'm going to look in to the handle part and as far as the sparking I will have to buy a inline tester but I've ohmed the coil, condenser, and the wires didn't have my filler gauge that day but had a micrometer and had a piece of metal that was close to .0.20 but wasnt really sure about were exactly the timing mark is I've seen different videos of different positions for it