lots of rust on engine block



My engine, especially the head, is slowly turning brown/white from sitting there exposed to the weather.

Is heat potentially a problem? anyone's engine extremely rusted and used for years without issue?

Most of the HT engine is actually aluminum so the white part I can understand (aluminum oxidizes white)....The brown is maybe rust streaking from the steel head bolt, nuts, or spark plug body? or possibly the byproducts of combustion that may be leaking out of the combustion chamber from a loose spark plug or faulty head gastey (pictures may be helpful).

Since aluminum is a good conductor of heat I would think it (oxidation) would not be a real big issue unless maybe the engine was severely oxidized and being used in a hot environment under high load conditions.....

In either case, it may be a good idea to clean the engine every once in a while to remove the oxidation....here is a site with some suggestions on how to do that...


Hope this helps you.

I think you have it covered Andy. Mine is looking very sad as well. I use it every day and for me it's the salt. Lol...I sure got some looks and smiles yesterday!
the salt is just killing my bike and engine. It looks like it's been through a war. I'm sure that the aluminum is "chinese aluminum" if you know what mean. A mixture of soy-beans and beer cans. I think I will take the motor out this spring and give it a good,cleaning,sanding and try to give it a bit of a shine. Finding a real good gasket for the muffler is another goal, that black crud is so messy.
There must be some sort of sealant u can use to put a surface film over the engine to prevent oxidation.You can also spray paint any engine parts then go over the tips of any parts(eg,cooling fins)with a dremel to highlight them.
What about not leaving it outside,or if it has to go outside get a descent/heavy duty cover to put-over your pride and joy.
I regularly spray everything with moving parts down with WD40 or a similar penetrating lube and wiping it off after 10-15 mins. This keeps everything protected from moisture and rust. I dont know if it would be wise to use on the engine or if it would even help but I know it works wonders for bikes. It does however collect a lot of dirt buildup but when it gets too nasty looking I just spray down the affected areas with solvent, immediately rinse and coat with a little more WD40 and wipe down again. Most of my raleigh MTB look brand new and I've been pedaling that thing around for more than 10 years without a hint of rust anywhere. For the engine I would say sand it all down and give it a few light coatings of high temp engine paint found at any automotive store. Remember to oil your control cables regularly aswell. Not only will it prevent rust and sticking but it should keep them from freezing up with water in the winter. Definitely invest in a cover that you can use to cover it up when not in use, if even just a small cover that you can cart around with you that covers the top half of the bike and will keep most rain and snow off of it. These kind of stories gives me a new respect for the HT engine kits and bicycles in general. I baby my bikes, they're parked in the garage whenever they're not in use and never used in the winter. Just amazing to see these things can endure a whole winter of punishment.
Has anyone tried polishing the engine and adding a clear coat to prevent oxidation? I've heard that painting the engine can cause the engine to run hotter (less efficient cooling).
Has anyone tried polishing the engine and adding a clear coat to prevent oxidation? I've heard that painting the engine can cause the engine to run hotter (less efficient cooling).
I've just read on another post that painting the engine makes it run cooler...now i've got the engine running hot and cold.
To my way of thinking anything additional over bare fins would inhibit cooling but i'm not 100% sure of my facts....i'll check further.