evinrude spark plug issues

[xjcj3a]

Re: evinrude spark plug issues

alittle back story on that, i used those plugs before i had the vro pump replaced with a straight fuel pump. the pump was failing for awhile and over oiling so i blamed the plugs and havnt moved past it. i bought a service manual today from eBay, so that's on its way. my local shop doesn't carry the champion plugs either. they said that champion 938m are what champion sells now. i havnt verified that but if they are the same im going to put those in. hopefully with this manual i can troubleshoot and fix my own issues. thanks for all your help!

 

[xjcj3a]

Re: evinrude spark plug issues

UPDATE:

Tried running the boat again today, boat would not idle for more then a few seconds at about 700 rpm. usually runs at about 900rpm. drained alittle gas and added a gallon of straight gas to 15 gallons of my premix. this helped alittle as boat would idle for more then 15 seconds but no more then 700 rpm.

I was able to finally put the boat into forward and was able to plane the boat, RPM's seemed alittle high for the speed i was at. pulled the boat out of the water and checked spark at all cylinders. A bright blue spark from every plug, and plugs had very little oily residue on them, which isnt like it was earlier in the night.

tomorow i am going to fully drain the tank(or as much as i can manage to drain, tank is below the floor) and start with a fresh 5 gallons of 50:1.


Everyone has been great so far with the help and feedback. Should i mix the 5 gallons at like 45:1 or even 40:1 to try and get some of the residual gas thinned out?

Anything else i should check here? My book wont arrive until monday and its going to be in the 100's the next few days. Any help is greatly appreciated.

 

[Daviet]

Re: evinrude spark plug issues

Do you know anyone that might have a portable tank you can borrow, would eliminate the complete fuel system in your boat.

 

[xjcj3a]

Re: evinrude spark plug issues

good point, but sadly i dont. I dont know anyone else with a boat.

 

[Chris1956]

Re: evinrude spark plug issues

Stick with 50::1 fuel mix. Nothing can be gained by using anything else, and using too little oil is a problem. Make sure you siphon the fuel out of your tank from the bottom, so you get any dirt or water.

 

[xjcj3a]

Re: evinrude spark plug issues

I just keep thinking its bad gas because of how great it ran all morning, and that entire week. But when i put gas in from a station with pumps that have been there since the 80's everything started to go bad. I am unsure of how to check the timing as i have read that thats the only way to adjust idle on this motor?

I have tried understanding joe reeves post on the issue, but i cant visualize the procedure. I guess this winter i will just do carb rebuilds and do a good tune up on it. Waiting to see the book i bought to see what kind of information that baby contains.

Thanks for all the help

 

[belairbrian]

Re: evinrude spark plug issues

my local shop doesn't carry the champion plugs either. they said that champion 938m are what champion sells now.

938M is a Federal Mogul Number for a QL78YC. Federal Mogul bought Champion. Enter QL78YC in the Federal Mogul website and you will get the cross reference.

Autozone carries them under 938-1. That is the part number for a single QL78YC in a blister pack.

 

[xjcj3a]

Re: evinrude spark plug issues

i checked with autozone and the 938-1 looks like its for a 4 stroke engine. does that even matter?

 

[Daviet]

Re: evinrude spark plug issues

I didn't notice if you listed a model number, but the parts breakdown I looked at, listed the QL78YC as the correct plug for your engine.
That's the plug I would put in it.

 

[xjcj3a]

Re: evinrude spark plug issues

so i am going to buy a new inline fuel filter, drain the tank and drain the carbs. then try and find some none ethanol gas and remix and see where that gets me.

 

[xjcj3a]

Re: evinrude spark plug issues

Update 2:

Think i have bigger issues then i imagined.

Drained all the fuel from my tank, drained the carbs. Fresh premium gas and i know the mix is spot on. Boat would idle for awhile on muffs. but it was rough. Took it to the river and same running issues before. maybe alittle more rpms. but were talking 100 more tops. so a steady 750.

Was able to get it into forward without it dieing and ran the motor. still very little power. This time, boat was SPEWING water from around the pee hole. I mean a solid inch stream of water on each side of it. took the boat back to the trailer and had it idle. the water would only come from the pee hole but it was ice cold. I'm now thinking blown head gasket, or open thermostat which someone mentioned before. Without diagrams for this motor at this point i have no clue where the thermostat is. I'm trying so hard to get this thing fixed and keep striking out. Frustrated is an understatement. if anyone has more thoughts i really do like to hear them. thanks again.