Fuel/Oil Ratio Problem

[gdombroski]

Have a 94 8HP Johnson trolling motor. Have mixed at 50/1 ration but plugs get oil fouled after a couple of fishing trips. Read on a spark plug site that for 2 cylinders that is caused by to much oil. Would reducing oil mix hurt?

 

[iwombat]

Re: Fuel/Oil Ratio Problem

It's caused by a whole bunch of things. That 8hp should run for hours on end w/o fouling plugs. When is the last time you performed a dacarb?

 

[JB]

Re: Fuel/Oil Ratio Problem

Yes, reducing the oil in the mix would be risky.

If you use it exclusively for trolling, go to a hotter plug (1 range only) and open the gap to .040".

 

[ezeke]

Re: Fuel/Oil Ratio Problem

Reducing the oil will most likely harm your engine.

In order of priority, the following items will help to reduce the carbon which if found on the spark plugs will also be found on all of the firing chamber, rings, pistons and exhaust:

1. Make sure that the thermostats are the correct ones for your motor, and that they function properly;

2. Use Synthetic blend or 100% synthetic oil;

3: Perform the recommended annual de-carbon treatment and use a carbon treatment additive in your fuel whenever you buy fresh fuel, and do the de-carbon treastment now;

4: Check with your local BRP dealer to be sure that you have the correct plugs and gap.



http://forums.iboats.com/showthread.php?t=158076

 

[gdombroski]

Re: Fuel/Oil Ratio Problem

Waht's a decarb?

 

[ezeke]

Re: Fuel/Oil Ratio Problem

Chemically removing the built-up carbon from the engine. De-carb thread:

http://forums.iboats.com/showthread.php?t=158076

 

[iwombat]

Re: Fuel/Oil Ratio Problem

A decarb is especially important on a trolling motor. I do my 8hp kicker every 50hours of service at minimum.

 

[kenmyfam]

Re: Fuel/Oil Ratio Problem

Reducing the amount of oil is dicing with motor damage. Dont do it. A decarb will get rid of the built up carbon crud in your motor and will certainly not harm your situation only help it.

 

[OptsyEagle]

Re: Fuel/Oil Ratio Problem

One more point that I don't think was mentioned is that you may be running too rich. Make sure that you have adjusted your slow speed carburetor adjustment properly. Joe Reeves has put a great procedure for that on this site. If you have a high speed adjust, make sure it is set right as well, but the low speed adjust is critical, especially if you are trolling a lot. A too rich mixture will foul plugs pretty quick.