What do my plug colors indicate? Pics inside

gwoloshyn · Jul 7, 2013

I'm currently breaking in a rebuilt motor and when pulling the plugs after todays run I found this. In the first picture, the plugs are lined up left to right for cylinders 1-4 respectively. Cylinder 2 is showing a clean white color around the outside, does this indicate a leaking head gasket? None of the plugs look the same, but the others are a least a light or dark brown color.

The motor is also making a very noticable rattle noise at low and high RPM. Sounds like it's coming from inside the powerhead.

This motor was bought from Outboard Exchange out of Waterford CT, and I would NEVER recommend buying a remanufactured motor from them.

w2much · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

2 and 3 look to be water washed. Check your compression. Good luck.

gwoloshyn · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

Forgot to mention the compression is an equal 110 psi in all 4 cylinders.

Watermann · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

I hope the motor still inside the warranty, rattling inside the power head could be piston slap from water in the cylinder(s) that doesn't compress. Those 2 and 3 plugs do look steam cleaned to me too. Have you re-torqued the head bolts yet?

gwoloshyn · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

YES, the motor is still inside the warranty. What sucks is that I'm in upstate NY and they are in CT, I would have to pull this pig off the boat or haul it there with the boat. I would be more inclined to do the work myself, I'm pretty good at working on these.

The torque on the cylinder head bolts is good at 20 ft lbs for those, but what about the cylinder head COVER bolts? Are these also supposed to be at 20 ft lbs? If so, these bolts are WAY loose and all need to be tightened.

boobie · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

The plugs wouldn't worry me right now, it's the rattle that you're hearing that would bother me.

gwoloshyn · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

I believe the torque specs for the cylinder head COVER are 5-7 ft lbs. Those had to be re-torqued a little.

When I re-torque the head bolts, do I need to back the bolt loose a little then re-torque?

Watermann · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

All the cover bolts would do it leak water out, not inside the motor. Re-torquing, I've always just ran the torque pattern again, I think backing them off would not be a good idea.

PlankingThing · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

w2much said:
2 and 3 look to be water washed. Check your compression. Good luck.

I Take it this is a Two Stroke ?

I Don't have the Foggiest Idea , How Water could Wash Plugs down , but anyhow those Plugs do look Wet !

Like too much Fuel , and Not enough Oil : 2 & 3 really the one Plugs has gray deposit on the Porcelain _ Which
looks like it's from : Heat or too Lean _ Condition .

If this is a New motor and under Warrant - have You previously had some Hard Miles
on Motor - so You could say it is _ Fully Broken _ In ? ( Material Coatings in Cly Walls )

This is an Older Motor Not Fuel Injected ? ( I take It ) - If so that sends Me toward
High Speed Jet and Low Speed Jets _ Not set Properly . ( My Best Guess ) :facepalm:

My Snowmobiles always ran a Gray to Light Cocoa Brown .

dazk14 · Jul 7, 2013

Re: What do my plug colors indicate? Pics inside

Torque values are a dynamic(movement) value, not a static value.

Run your tightening sequence and break the "sticktion" of the bolt 1st. Do not loosen them all at once. Do them individually, slight loosen, re-torque. Move to the next head bolt.

With the proper setting on your torque wrench, you might get the head bolts to move without cracking them loose, that's fine. The main issue is the torque be reached while there is movement.

gwoloshyn · Jul 8, 2013

Re: What do my plug colors indicate? Pics inside

I'm ready to pull the heads and inspect but before I do, can anyone tell me that if I am indeed getting water in, could I still be getting good compression?

dazk14 · Jul 8, 2013

Re: What do my plug colors indicate? Pics inside

I'm tending to see mixture issues here. How does the motor run? Have you checked the size of the main jets(67C) on the leaner firing cylinders as those carbs are used on other models albeit with smaller jets.

Outboard exchange does pull parts from different motors to put those together, but they have done quite a few over the years.

The idle jets are fairly close between the 110 and smaller V4's, so it may idle ok and coat the plugs at lower speed, masking a higher throttle lean condition.

What is Tim at Outboard exchange telling you.

The NGK's do run a bit hotter than the champions, so you may want to switch over to the QL77's.

gwoloshyn · Jul 8, 2013

Re: What do my plug colors indicate? Pics inside

My motor has two carburetors one for the left and one for the right. I haven't checked the size of the main jets but will do so. The motor runs great, just has the rattle/knock all through RPM ranges. It sounds like it's getting worst, so I'm not running the motor anymore until this is fixed.

I tried checking for rod play with a dowel through the spark plug hole, and each cylinder shows no play.

What I noticed just now is that the cylinder in question, number 2 with the clean white plug, has a completely clean piston also. All other pistons have some carbon deposits, but this one looks brand new.

I haven't tried Tim yet, he hasn't returned my call about the rectifier I needed that was also faulty, so I'm through with them.

dazk14 · Jul 8, 2013

Re: What do my plug colors indicate? Pics inside

You have 2 carbs, but they are upper and lower. They each share a fuel bowl, but have separate metering circuits (read individual jets for each cylinder).

You can pull the main jet without removing the carb or bowl. Since you switched your camera orientation, the order is confusing, but 2 it is.

Upper carb, port side, remove the plug screw and o-ring, then the jet. It is located on the lower side of the bowl.

Use a quality screwdriver and do not damage the bore threads or the slot in the jet. Expect some fuel to dribble out.

I believe those 6 in 1 screwdrivers will work, as they are straight shaft with decent slot thickness.
looking for 67C or bigger main jet.

Check the above before pulling head and you may as well check cyl 3 (lower stbd).

gwoloshyn · Jul 8, 2013

Re: What do my plug colors indicate? Pics inside

I checked these cylinders and they are using a 68C jet.

After doing some reading I suppose it could be a bad Exhaust Cover Gasket? Should I check here first considering I have good compression on all cylinders?

Tripp Halbert · Jul 30, 2013

Re: What do my plug colors indicate? Pics inside

Similar situation here. good compression, runs good, but clean plug?:facepalm: Hope someone can help figure this out!

What do my plug colors indicate? Pics inside

Petty Officer 2nd Class

Lieutenant

Petty Officer 2nd Class

Starmada Splash of the Year 2014

Petty Officer 2nd Class

Supreme Mariner

Petty Officer 2nd Class

Starmada Splash of the Year 2014

Recruit

Ensign

Petty Officer 2nd Class

Ensign

Petty Officer 2nd Class

Ensign

Petty Officer 2nd Class

Petty Officer 1st Class