Hi All, what could be causing the the plugs to foul quickly, usually under 10 hours of service.
Thanks
Geo🇺🇸

 

How much and often do you add oil? My guess is piston rings and/or valve stem seals worn.

 

I would check for a blown head gasket.

 

Not likely since engine is a V twin. Owner said plugs, not plug, fouled.

 

Stopped up or bad air filter. Sometimes the cup that protects the filter from spitback from the carb is missing and the filter gets wet with gas and even when it dries out, it can be restricted. How are they fouled? Oily black? Sooty black? Bad fuel pump leaking gas into crankcase, leaking carb, partially closed choke, blowby, just some things off the top of my head.

 

Thanks for the reply Cheese, I am getting 2nd hand information, a little background, the motor was completely submerged by seawater during Ian, fluids, filters, gas tank drained, Seafoam added , carb replaced with new OEM , runs well until the plugs foul out , once they are replaced it runs good for awhile.
Geo🇺🇸

 

Quite a large omission of fact. People responding to this post before this fact manifested had their time wasted in my opinion.

 

Huh? How does that really change anything? The things that foul a plug are still the same.

Geo, does the engine smoke? What is compression? Have you tried a leakdown test? Could be head gaskets too. Improper load, as in lugging under low rpm. Wrong temp range plugs (probably calls for champion RC12YC plugs), some other things that could do it. I'd start with the first things I suggested earlier though. Try with the filter off if it's not operating under dusty conditions.

 

Cheese, yes it does change things in my book. Corrosion is different than friction.

 

No smoke has been reported, I will suggest a compression test , plugs are correct ones, not familiar with a leak down test but I am sure we can find something online.
Geo🇺🇸

 

Hi All, after removing the front cover around the flywheel to expose the armature’s it was quite clear the probable cause of fouled plugs, it is amazing that the engine ran as well as it did, all new parts will be ordered and replaced

 

What has happened here? It looks like the coils have rubbed the flywheel down, then someone kept adjusting them tighter and tighter to keep rubbing the flywheel? This is strange. Or is that just how the machining was done on the flywheel? The rust shouldn't change timing or any aspect of how it works.

 

Cheese, the OP says engine runs about 10 hours before plugs foul so I doubt there is a gap issue. All I see in the photos is evidence of salt water corrosion.

 

Hi Cheese, I have removed the armature’s, don’t believe anyone has ever been inside there, plan is to remove flywheel, wire brush with a bench machine or what ever it takes to make it shine, replace Alternator, armature’s reg/ rectifier, diodes, starter motor and solenoid, replace all corroded wiring basically rebuild the front end.
I’ll keep you posted, hope to order parts the middle of the week.
Any other suggestions?
Geo

 

Geochurchi, you say you are replacing Alternator, armature’s reg/ rectifier, diodes, starter motor, solenoid and replacing all corroded wiring . What happened to the fouled plug issue stated post 1?

 

Possibly lower voltage to the plugs , don’t really know.
Geo🇺🇸

 

After doing a compression test I believe a short block maybe an order, I will have one of the other guys verify this week if possible, what would be considered good readings?
What parts come with a Vtwin short block? I know we reuse a lot of parts from the old engine.
Geo🇺🇸

 

cheese asked how the plugs are fouled or even a pic of the fouled plugs so really no way of knowing if the plugs is oil or fuel fouled, fuel is often just a black sooty plug, and oil can often have oil deposits built up on the plug and may be oily in really severe cases but you would set about fixing the problem based on how the plugs are fouling.

 

A compression test isn't going to give high numbers on this engine unless you loosen the valve adjustments enough to deactivate the compression release. That's why I suggested a leakdown test. The shortblock is going to be a block with the internals installed. That's it. You'll use your old heads and everything else. Not recommended at this point.

 

Hi All, we have spark, fuel, still want start, backfires some but will not run , new carb , fuel filter , armature’s , will a leak down test help solve the issue?
Thanks
Geo🇺🇸

 

might look at the chart below showing pictures of spark plugs and what yours looks like then go from there on common problems of the type of fouling you have carbon fouling is usually fuel issue and even though a plug may look wet when you first pull it the gas will evaporate fairly quickly oil will not and any oil or ash deposits likely is an engine problem.
spark-plug-condition-chart.jpg (640×875) (jagexp.com)

 

Geochurchi, posts 1 and 8 state engine is running. What happened between post 8 and 20? Are you doing the work on this engine or are you an intermediary?

 

It was running after the plugs were changed, but not well , hence the post, both intermediary and repairing.need more advice and less scrutiny.
Geo🇺🇸

 

I see the flywheel nut was removed in the last photo (taking the flywheel off to clean it). Might check the flywheel key.
I don't think a shortblock is the answer at this point. With a shortblock you'll get the block with internals in it and that's it. You'll use your old heads and everything else that is bolted to the block. Not recommended at this point.

 

Cheese, We checked the key seems OK, we rotated the flywheel by hand and have determined that the spark should happen near TDC by the position of the magnets on the flywheel, a bit crude I must admit, thinking of changing plugs to RC12YC OEM specs , the ones they have in there now are supposedly equal, who knows, would low compression cause starting issues, thinking of purchasing a leak down test kit, also thinking about a new replacement motor although availability is an issue.
Geo🇺🇸

 

You can do a sort of leakdown test without buying a kit. Get a rubber tipped air blower nozzle and connect it to a compressor air hose. Take the plugs out and the oil cap off and put the cylinder to be tested at BDC of the power stroke. Pressurize the cylinder with the rubber tipped air blower in the spark plug hole. You will hear and possibly feel where the air escapes. If lots of air comes out the oil cap, you have a blown head gasket(s) or bad blowby from the rings. If lots comes from the carb, you have intake valve problems. If lots comes from the exhaust, you have exhaust valve problems. A small amount will come through the oil fill tube by blowing past the ring end gaps. That is normal. I'd still like to know if the fouling on the plugs is oily, powdery, or what. I would put known correct plugs in first, that would be step #1.

 

Cheese, going back to Sq One, new correct plugs gapped correctly, and I will report back as to condition of plugs, from what I saw the plugs were black, not oil fouled.
Geo🇺🇸

 

Some people solve a problem by approaching it smarter, others do it by working harder.

 

What is the point of these posts Bob? You are wasting more time criticizing and making useless posts instead of offering any solutions. In post #9 you seemed pretty concerned about wasted time, yet you continue. Not everyone is proficient at diagnostics and repair. If they were, this forum wouldn't be here. Post helpful information or none at all. Thank you.

 

Cheese, read the PM, I assume that 1/2 way up the compression stroke would be just before the spark occurs at TDC, I am determining that roughly by the position of the magnet on the flywheel, why would I not at least get a pop when there is gas poured into the cylinder ?
Geo🇺🇸

 

Noticed responses are not in chronological order. Does anyone else see or have this issue?

 

They appear to be in chronological order, however the order has been reversed. It used to be the newest were at the top, now they're at the bottom.

 

there all over the place for me not sure why think its part of the reason it confusing not sure if this is fouling plugs or not running at all at this point.

 

Cheese, thanks for the criticism. I would also point out this thread is over 2 weeks old with 23 responses and the fouled plug problem isn’t one step closer to being solved. I asked a question in response 2. Still waiting for an answer. Someone else asked for a photo of the fouled plugs. Still waiting for a photo. Both seem like pertinent requests. Isn’t it the moderators responsibility to keep the thread on track?

 

Hi All, I’ll put a end to all of this unrest, we can’t afford to have this motor out of service any longer so a new motor has been ordered and this one will be repaired as a spare at a later date.
Geo🇺🇸

 

23 responses, that's now your big concern, yet you yourself made over 1/3 of them. 9 to be exact, and only one offers a reason for the fouling issue. And no, you didn't ask for photos of the plugs. My job here is to help the members find solutions and protect them and the forum from inappropriate content, be it advertising, troll posts, abusive language, abrasive personalities, or whatever the case.

 

I think this thread has run its course.