Topic: Results of highway run... HOT

[beaniam]

Took my recently almost finished 78 750k on about a 40 mile run, half freeway miles today.



Does great regular riding and cruising however after I got off the freeway from my 20 miles of about 75mph running and stopped at the red light I noticed it was pretty hot.  I don't have an IR thermometer but to the point of smoke coming out of the valve cover breather and 0 oil pressure at idle (was holding about 30 on the freeway as I kept checking it).  Blip the throttle to about 1500 - 2000 and oil pressure went to about 20.  Today is only about 70 degrees out. 
Once I continued cruising regular driving and it cooled off it was fine.  Oil pressure went back up to a safe point.  I've got 4-1 and pods with 115 jets.  I have an aux oil cooler that I never put back on after pulling the engine a month ago.  My plan is to put 120 jets in, the aux oil cooler back on, drain the 10w40 oil and replace it with 20w50.  At regular riding idle I've got about 30psi oil pressure.  Cold idle 60.  Anything else I should try, or go with this plan first and see how it does?

[Cuts Crooked]

I'm running 120 mains on my 78K with pods, but I've got a stock exhaust system. You might want to consider going to 125s with that aftermarket exhaust you are running on that thing.

What do your spark plugs tell you?

[beaniam]

Wasn't able to do a plug chop but looking at them now they are dark tan, slightly sooty.  But that's after some 35mph putting around.  I'm thinking it really doesn't like the 115's at those highway rpms.  I'll order some 125's and see how it does on the 120's.

[seaweb11]

A few of us here with 78s have found success with 138mains with your set up.

[beaniam]

Wow that big?  I'll do some experimenting and drilling with my old extra mains

[beaniam]

A few of us here with 78s have found success with 138mains with your set up.

I'm curious what sort of mpg do you get running 138's?

[seaweb11]

I think we had it figured to 45-50mpg on the trip to Sturgis.....and who really cares   It's a bike, I was never interested until my riding partners said something about no gas stations for a few hundred miles coming up, so we kept track on the next tank.

[beaniam]

That's better than I get now.  I'll drill out my old set to 138 and see how it goes.