Hey all,
I'm new here. Just picked up my first evo the other week. I bought it to have a "reliable" bike to commute on. Not my first Harley, other bikes are 51 FL, 79 FXEF and 70 XLCH.

So this bike is a 1994 FXD. I picked it up here in Sydney Australia. Only has 22,000 kms on the clock. I had hoped with such low k's it would be in pretty good shape. Took it out for the first decent ride on the weekend. After about 1/2 hour of riding the oil pressure light came on. First at idle at traffic lights, when I revved the bike up a bit it would flicker out but gradually required higher and higher revs to keep the light off. I turned around and took it home.

I checked the oil level and it's fine. Running 20w50. New oil filter and fresh oil. My first thought is a faulty oil pressure switch, i have ordered a new one waiting for it to arrive. I wondered if maybe the bike and therefore the switch heating up was expanding some kind of crack in the switch causing the light to come on?

I also noticed some oil, not much but a definite accumulation on the rear cylinder from the back of the head gasket, obviously this means the head gasket is going. Could this potentially be causing the oil pressure issue? Is there anything else i should be checking?

Thanks

 

Oil pump relief spring.

Oh yeah, welcome to the site.

Check the oil screen for obstructions while you're there.

Get a dial oil pressure gauge and install it in the correct hole. (It can thread in either hole, btw.))

 

Doubt it's the head gasket on the rear cylinder... Probably just the rocker box's. As for the oil pressure 20w-50 is a good choice just stick with Dino (don't know much about temps in aussieland)...... a gauge is a good recommendation. switch could be the issue, these Evo's don't have a lot of pressure at idle.. Only 6-10 on a good day..

 

Hey Norty,
Thanks for that, is it commonly the relief spring that causes that issue? I just ordered one so I'll give that a go. It's strange that it's always fine when it's cold.

 

98hotrodfatboy, It's definitely leaking oil from the head gasket but good to know that's likely not what's causing the oil pressure issue. I might have to replace those head gaskets at some stage soon.





I rode the bike back the other day, about another 20 mins or so after the light came on. Hope that I didn't do too much damage.

 

Small update, I pulled the tappet screen and cleaned it out, was dirty and some very small shavings, likely it's never been cleaned. Pulled the return line to check that oil was indeed returning. I'm not sure how much these bikes should flow but after about 30 seconds of running some drops started spraying from the return line but it was minimal. Does that sound right. I held my hand under the line and after another 20-30 seconds, my hand had a puddle of oil.