1975 R90/6 600 Mile Service post rebuild

[clmedlin]

Hopefully looking for some insight. I completed a thorough 600 Mile service today of my recently rebuilt r90/6. Everything looked good on the bike, it runs well, all the fluids looked good. Had to adjust my valves slightly (all 4) - but my oil filter was an absolute pain to pull out and was just as difficult to install the new one. Outer cover plate and inner cover had no issues. I had to pry it out with a pick and needed to tap the new one in. I am waiting to seal it up until I know what’s going on.

Any help would be appreciated.

 

[20774]

That's unusual. What do you see when you shine a bright light into the cavity?

 

[RPGR90s]

Filter brand please.

 

[clmedlin]

That's unusual. What do you see when you shine a bright light into the cavity?

It looked good - I had cleaned it thoroughly during rebuild. The tube the filter slides onto is mared a bit at the bottom left. I sanded it a bit with fine grit but it did not help.

 

[clmedlin]

Filter brand please.

Purchased from boxer2valve

 

[RPGR90s]

Purchased from boxer2valve

hmmm, that's pretty much the approved brand. Any possibility that the internal opening of the filter is smaller in diameter than the one you removed? Maybe a quality issue with the one new filter.

 

[20774]

Is the pipe in the center of the cavity equally spaced from the sides? If it's tilted one direction, that could bind the filter going in.

 

[clmedlin]

It looks centered. It’s also not coming out unless I forcefully pry it out like the previous one.

 

[20774]

Hmm...it does more or less look OK. There typically would be some room around the filter...it doesn't take up the entire volume.

That o-ring does look compressed. I don't have much to go on and can't find anything online about the central pipe. I found an old filter I used for my /7. The ID of the rubber o-ring on the end of the filter is around 15mm. From memory, when I installed the filter in the past there would have been some interference with the o-ring and the pipe. Do you have measurements of the ID of your filter black washer and the OD of the central pipe?

Just to be sure we're on the same page, the oil filter cover on your bike is a simple flat plate? Like the one at the top of this page:

Airhead oil filters

Underneath that cover, you would have another cover with a central bolt.

 

[kinterridge]

The only thing I can think might be the issue, with everything being original, is if the tube has an arc in it, in the center and being the hinged filter it has it tight to one side in the center of the run. I don't think it would be an issue if it was the one piece filter. Just a guess.

 

[clmedlin]

Hmm...it does more or less look OK. There typically would be some room around the filter...it doesn't take up the entire volume.

That o-ring does look compressed. I don't have much to go on and can't find anything online about the central pipe. I found an old filter I used for my /7. The ID of the rubber o-ring on the end of the filter is around 15mm. From memory, when I installed the filter in the past there would have been some interference with the o-ring and the pipe. Do you have measurements of the ID of your filter black washer and the OD of the central pipe?

Just to be sure we're on the same page, the oil filter cover on your bike is a simple flat plate? Like the one at the top of this page:

Airhead oil filters

Underneath that cover, you would have another cover with a central bolt.

The ID of the filter o-ring is 14.92mm. Attached photo of the inner and outer covers.

 

[clmedlin]

The only thing I can think might be the issue, with everything being original, is if the tube has an arc in it, in the center and being the hinged filter it has it tight to one side in the center of the run. I don't think it would be an issue if it was the one piece filter. Just a guess.

My plan at the next service was to see if the 1 piece filter had better fitment. Im just hesitant to ignore my current fitment issue and close it back up and ride…especially if I am missing the obvious and potentially doing damage to the bike. This is my first experience with an airhead and it is an absolute blast to ride.

 

[20774]

I would definitely look into what kinterridge suggested. If you haven't buttoned things up, easy enough to check.

 

[m_stock10506]

For removing an Airhead oil filter, I use a standard wire coat hanger. The end of the top hook is straightened, and then a small hook is made on the end. You slide the hook into the recess and hook onto the leading edge of the filter. It slides out.

 

[clmedlin]

Just to close this out - I completed the 600 mile service and closed everything up. I opted to “wait and see” if I have any issues instead of prying out a new oil filter. But I will definitely use the 1 piece filter on the next service.

On a side note - I switched oils on the recommendation of boxer2valve to a 20w-50 (actually used Liqui Molly) - for the first 600 miles I ran same oil I had use in my 2015 GS - Castrol Power 1 Racing 4T 5W-40 engine. There is a noticeable difference in the way the bike runs - I’ve put about 150 miles on the bike since the service.

Being new to the MOA - I truly appreciate all the feedback from the community. S/F!

 

[20774]

Glad things are working out!

 

[clmedlin]

I am re-engaging on this thread. My oil pressure light is on constantly now. I’ve put about 150 miles on the bike since completing the service. What could be going on? It all had to be related in my mind.

Any insight would be appreciated.

 

[r0ckrat]

A few things come to mind.
1) The oil filter situation mentioned earlier may be restricting flow.
2) The oil pressure sensor may be providing a bad reading, whether from bad connections or a bad sensor.
3) There is something else wrong in the oil pickup and delivery system.

Since you did not have issues prior to the 600 mile change, I would revisit what was done at that time, and resolve any issues with the filter situation first.

 

[20774]

You need to consider what might be happening. If you do indeed have low pressure and you've been running the engine for a while, there is danger of engine damage.

I'm a little confused. You said in #15 that you put about 150 miles on the bike...no mention of the light. Then in #17 you say that the light is constantly on after 150 miles. Has the light been on for the whole 150 miles or has it not come on after the second 150?

Consider trying a new oil pressure sending unit.

 

[kbasa]

Ugh. Let's hope this isn't the dreaded "cooked the bottom end because I got the gaskets in wrong" situation.

oil pressure light should never be on when running.