[David Jr Worsham]

I accidentally used a mineral oil based oil. Went on a very short ride, bike overheated. Woouldn't start after cooling down. Flushed out with a quart of oil, then did a regular oil change. Motor sounds like it wants to turn over, and has compression. How much damage could I have done?

 

[Goober]

“Sounds like it wants to turn over?” Don’t know what you mean—is it seized up and won’t turn? If so then it’s done.

If you can see it has compression then it’s turning over? What do you mean by has compression—are you testing it with a gauge? Is it within the range specified by the service manual?

If it’s doing all that I would Check the spark plug and try starting it. Is it making any noise? Smoke? Shut er down she’s done.

 

[mrbb]

what exact oil did you use?
Exactly HOW long was it running?
better info you tell us, better we can help you

 

[shadetree]

from the sounds of it ^^ ?, I would think the cylinder/motor is ruined ?, but without hearing/seeing it ?, hard to say.

 

[alloutdoors]

When you say mineral oil, what exactly did you use? When you say overheat, did the engine stop, hot light, etc., or seize?

 

[David Jr Worsham]

I used Bel Ray "Thumper" semi synthetic oil. It shut down after 15 minutes or so. There is no "hot light" on the 400ex. Not smoking, battery has 13.1 volts on it, new spark plug. But now fuel is coming out the overflow tube so time to clean the carb I guess. There is no knocking, pinging, etc.

 

[mrbb]

if that's the oil you used, it says it is FINE for your HONDA atv
so, that is NOT your problem, unless you didn;t use enough oil and it got HOT from LOW Oil
OR, and not sure if possible, maybe you put oil filter in backwards(its possible on some honda atv's, not sure on your;s or not)

but that oil is fine oil and wouldn't;t have caused you any problem
I'd start with pulling the spark plug, and seeing what that looks like, and from there, try pulling it over(AKA< pull cord/kick starter)
and see if she is free or not
if free, I;d do a compression test and see what that says
and come back and tell us , what happened from this?

here is info off the bel ray site for that oil

if the below is what you used and used right amount, its NOT this oil that caused you your problem


Bel-Ray Thumper Racing Synthetic Ester Blend 4T Engine Oil
Applications:
For use in all 4-stroke engines requiring an oil meeting the API SG/SH/SJ/SL/SM/SN standards For use in all 4-stroke motorcycles with or without wet clutches including those specifying the use of a JASO MA/MA1/MA2 qualified oil Use in all 4-stroke motorcycle engines with or without wet clutches