oil temp HOT when cruzing?

[Steven]

I got one of those "heat seeker" oil temp guages and I have a concern.

When I run hard at the mx track, oil temp stays a cool 220-250 degrees. When I go trail riding and cruz around easily with minimal engine load, the oil temp runs into the read at 275-300 degrees.

Why would the engine oil get hotter with less load and more air flow over the engine? No i'm not luging the engine around either.

I'm thinking a part throttle lean condition in the midrange. What do you think?

175 main, needle clip on the 3rd grove, 45 pilot, idle screw 4 turns out.

Steve

[MIKE400EX]

You may be right! Try the needle clip in the fourth position, a 42 pilot and the idle screw at about 2.5 turns.

[toby400ex]

Maybe its because more air is running through the oil cooler when you are going fast:confused:

[Steven]

I tried the clip in the 4th position and throttle response was good but it would barely idle with the 45 pilot. I turned the idle screw out one turn and it idled better but still rich and rough. I've ordered the 42 pilot which should cure the idle.

Its good to know that throttle response is still crisp with the needle clip in the 4th position.... must have been lean in the midrange. Can't wait to try it once the new pilot gets in. I'll bet it runs cooler.

I also just changed the oil and used mobil1 15w50 (red cap). That should help a little too.

I'll keep ya posted.

[cals400ex]

i was having a similar problem with jetting the bike. i was running the needle in the 4th position and a 42 pilot. i was pretty rich. i then installed a 45 pilot and moved the clip in the 3rd position and it fixed my problem. i am not rich anymore and the bike runs great. in the middle of winter, the bike ran great and not rich with the needle in the 4th position but if its not really cold, it didn't work best for me.