I bought my 2010 ultra limited with 37,000 miles. She now has 111,000 miles. They found a leaking seal and opened her up. They said 1 head bolt was finger tight. The head came off and the valves were rusty. I NEVER had a problem. Always started..no noise, yet the valves were coated with rust. How is this possible INSIDE a cylinder? Pulling the plug on the front cylinder showed rust on the plug. Shouldn't detonation blow off any rust? I was asked and NO.. the bike has never been under water.

 

Hi there hdflhtk, GOOD to have you with us. Feel free to click HERE for it will take you to the Welcome Area Only and you can share with us a bit about yourself as others have. And feel free to upload a PIX of your bike.

Lastly my friend, in the upper area of the Welcome Area Only are the few HDF rules we have. <-- Be sure to check it out eh?

GREAT having you with us and sry to hear abt the rusty valves 'n all.

 

Does the other head also have rust?

 

If you start your motorcycle often without riding it 10 to 15 miles the moisture from condensation doesn't have time to burn off and rust may occur. Is also bad on the oil as it will collect moisture as well (starts to look milky and or brown)
Does it have an open breather filter and or 1 that can possibly suck up water in the rain? Maybe picked up rain water and parked after without running for a while?
Personally wouldn't worry too much about it as it sounds like it has been a good one. Hope you have a great mechanic as in repaired correctly and good for another 100k!
Ride Safe✌🏼

 

Fun fact.... Burning 1 gallon of gasoline produces 1.03 gallons of water along with 20 pounds of planet destroying CO2 death gas.

If you look in the owner's guide, HD recommends more frequent oil changes in cooler weather due to water condensation mixing with the oil.

Out of curiosity where is the rust? I can't see a problem if its on the flat bottom of the valve... But it would be a problem on the seat face or stem.. Although friction should be wearing off any rust that might have accumulated off those areas.

 

Internal engine rust is not uncommon in areas where there is high humidity... and/or when a bike sits for a long time... but the loose head bolt is odd.... and the amount and location of the rust can suggest if it's a problem or not... You bought the bike with 37K miles, how would you know if it had never been submerged or at least exposed to some other water ingestion incident...?

In any case, any time you stop your engine, not all the valves are closed.. So at least one cylinder is exposed to the "atmosphere" from the exhaust and/or intake... That is why for long term storage, many people will fog an engine to coat the internal bare metal surfaces...

Additionally, as mentioned, shorter trips will not burn off the water in the oil and that can lead to moisture inside the engine...

An interesting engine rust story...
For 15 years I ran a boat that had twin Detroit Diesel 8V71TI engines. Their intakes are an air box, that gets pressurized via the blower at low rpm and then turbos at higher rpms. The cylinders are open to the air box, based on the position of the pistons, kind of like a 2 cycle gas engine (the 8V71s are 2 cycle diesels) and thus the surrounding atmosphere, when the engine is off. I bought this boat in Florida, and it had only 200 hours on in-frame rebuilds of the engines.... BUT..... it sat, unused, for over a year in the Florida humidity....

When I inspected the engines, prior to purchase, a borescope revealed rust in almost all cylinders from sitting in high humidity without use. Luckily, a sea trial cleaned off the surface rust, but it took a minor toll on the piston rings.... After the sea trail, a compression test showed it was in the lower portion of the acceptable range, even though they were low hour rebuilds...

I moved the boat to SoCal (dry climate relative to FL) and I put another 2800 hrs on those engines, using them frequently enough that rust never formed again...

The lesson to be learned is that the engines are not air tight, the surrounding environment and the bike's use patterns can allow for rust to form internally.... That's why proper maintenance is important, even on a bikes that sit a lot....

At 111,000 miles, a top end refresh wouldn't be a bad thing, or unheard of.... and finding a leaking seal, and a loose head bolt, that's exactly what I would do... it's time...

Good luck with your repair...

 

lol

 

Do you use fuel additives? A lot of fuel additives will give a reddish rust like appearance on spark plugs and valve faces.