Lawn Care Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
1,826 Posts
Discussion Starter · #1 ·
I changed the plugs on my ferris is3200 today (vanguard 37 hp efi) and found one of the spark plugs missing half the ceramic around the electrode (pictured below). I am assuming this happened while the plug was installed and from the looks of it it has likely been that way for a while. Engine runs good (I have noticed for the last few months it sometimes acts like it's only firing on one cylinder for a few seconds when I start it which I'm guessing is likely due to this spark plug so if that is the case I would say it broke off a couple months ago when that problem started happening.

I've researched it and best case scenario is the piece of ceramic broke up and got blown out through the exhaust port without causing any damage to the piston or exhaust valve seat but how likely is that?
There is no way the piece of ceramic could be still in there in any form other than dust at this point is there?

I haven't noticed any power problems, no more oil use than it has had from new, no change in the way the engine sounds. The broken plug looks about the same as the one from the other side.

Should I count my blessings and leave it alone or investigate further?


Automotive tire Wood Automotive wheel system Gas Tire
 

·
Registered
Joined
·
3,563 Posts
Should I count my blessings and leave it alone or investigate further?

I have to agree with @Scott87 . If it hasn't affected your engine by now, it's not going to. What I would like to know, is what brand of plug ? And where did they come from ?
.
 
  • Like
Reactions: tobylou8 and Dawson

·
Registered
Joined
·
1,826 Posts
Discussion Starter · #5 ·
I have to agree with @Scott87 . If it hasn't affected your engine by now, it's not going to. What I would like to know, is what brand of plug ? And where did they come from ?
.
Champion, they are what came in it from the factory. I replaced with ngk.
 

·
Registered
Joined
·
1,826 Posts
Discussion Starter · #6 ·
Those plugs look like crap, and I'm talking the part outside of the engine. How do you store that machine?
They are 3 years old, it's stored under my shed but it gets wet if it rains while I'm out working like any mower will.
 
  • Like
Reactions: tobylou8

·
Registered
Joined
·
422 Posts
I changed the plugs on my ferris is3200 today (vanguard 37 hp efi) and found one of the spark plugs missing half the ceramic around the electrode (pictured below). I am assuming this happened while the plug was installed and from the looks of it it has likely been that way for a while. Engine runs good (I have noticed for the last few months it sometimes acts like it's only firing on one cylinder for a few seconds when I start it which I'm guessing is likely due to this spark plug so if that is the case I would say it broke off a couple months ago when that problem started happening.

I've researched it and best case scenario is the piece of ceramic broke up and got blown out through the exhaust port without causing any damage to the piston or exhaust valve seat but how likely is that?
There is no way the piece of ceramic could be still in there in any form other than dust at this point is there?

I haven't noticed any power problems, no more oil use than it has had from new, no change in the way the engine sounds. The broken plug looks about the same as the one from the other side.

Should I count my blessings and leave it alone or investigate further?


View attachment 526763
Investigate further.

Lean conditions (on one cylinder) can cause the insulator to crack/break off.

It is an air-cooled engine, so be sure the fins of the heads are clean, and no debris are blocking the air passage on the damaged spark plug side.

Also check that intake bolts are tight. There are other checks to diagnose vacuum leaks with a "sensor safe" carb cleaner spray. If you are unfamiliar with troubleshooting lean condition issues, then better to have a good shop diagnose.

Surprised the EFI system did not set a code.
 

·
Registered
2013 GMC Sierra 1500 WT 4.3L V6
Joined
·
179 Posts
I don't think you have much to worry about in terms of that piece having fallen inside the engine, but I'd definitely pull covers and use compressed air to clean out the fins, that dirt build up is an ongoing issue that interferes with heat dissipation.
 

·
Registered
Joined
·
1,826 Posts
Discussion Starter · #11 ·
Thanks for the replies/suggestions, the issue on startup did not happen today so that broken plug was probably causing it. I plan to drop it off at the shop soon to get some warranty work done on the suspension so I'll have them hook up the computer while its there to see if everything is within spec.
 

·
Registered
Joined
·
2,326 Posts
Typically never change plugs. We'll get well over 2000 hrs on mower plugs. Handhelds wear out before plugs ever go bad.

Its part of our routine maintenance. Every 6 months equipment gets new plugs and air /fuel filters. Oil is changed every 100 hours. Mowers are greased and sharpened on a daily basis as well as belts being checked.

We have backpack blowers that are 4 seasons old that have not lost a bit of power and fire right up.

Again, its probably overkill but I want stuff running smoothly. The better the equipment runs the happier the employees are and the more that gets done.
 
1 - 15 of 15 Posts
Top