Airhead Flea Market Discussion Thread.

GS Oil Pan mod on R75/6. Hi folks. One of the inmates has been a great help with my questions but I don't want to wear the poor fellow out. I want to put an R80 GS oil pan and bash plate on my R75/6. I've found the pan and plate at an online seller (Re-Psycle in Ohio) and I'm told my current/OEM oil pan bolts will work with the GS pan. But I hear I need a GS dipstick (and the gasket, of course). I didn't think the GS pan was any deeper than the R75/6? If the GS pan is on an R75/6 is there a new oil capacity? Thanks.

According the Max fiche, both your R75/6 and my G/S use the same "B" dipstick.

Ahhh. That does make sense, at least visually. But the guy that told me it was different did the actual mod so I would think he would know. Puzzling.

Anton's website should clarify. He has a thorough discussion on various pans and dipsticks.

As stated by Uke Anton's site will have the info you need. I'll just add that if a different dip stick is needed you probably need a pick up tube extension. Anton should explain.

http://largiader.com/tech/oilpan/

that would depend on what you want to measure. The pick up extension gets the pickup to the bottom of the pan. the dipstic measures oil depth below the bottom of the block. I use a 75/5 dipstick on my '83 r100 engine because I like metal handles rather than plastic ones and the contour is more graceful. When I was running a briel cooler and a quart more oil I extended the dipstck tip but I was just screwing around. I had so much oil on board the depth meant little.

Oh, man. We’re now in the world of “I have no idea what you’re talking about and if I did would it change anything?” Ordered the Oil pan, matching bash plate and hardware. It’s from a ‘93 GS, I’m told. Also ordered a “C” dipstick but I’m not sure why. Don’t I just need to know the fill level? Why do I need to know the “too low” level if I’ll never let it get there? Thanks!

Well, when it does get there, and it will, maybe, you'll want to know how much too low it is.

Some run the deep pan low to give the extra space to air. Lowers windage, more performance.

Did you also order / buy the oil pick-up extender? If yes you can run the recommended oil volume and decrease windage or run to full on your original dipstick and carry extra oil which isn't a bad thing.

Hmmm. No, didn’t order the pick-up extender. Is that the basket with the holes? If so how does that decrease wind age? I thought I read the 93 pan is only a 1/2” lower/deeper than the 74 I have now. Doesn’t seem like a lot of volume or wind resistance? Or am I not understanding you, Uke? Thanks for all this help! I also watched Brook’s video on changing the pan, cleaning, new gasket, etc.

SteamD, why the bash plate? I'm asking because I am planning to ride my 1975 R90/6 on some not-so-good off roads. Do I need to protect my pan with a bash plate? Thanks, Ron

Hi Ron,

It’s probably an excess of caution and reading too many ADVR pages. Plus this revzilla story. There are a zillion miles of dirt logging roads (aka FSRs - Forest Service Roads) in my beautiful province (as well as the neighbours) and I’d like to ride some of them with a bit of reduced worry. Frankly I don’t think I’ve come across a single “rocks tore open my airhead oil pan” tales but maybe they’re out there.

PS I can’t find the thread right now but John Wesley did some really nice off-road mods on his airhead. Inspired me. But his is for a lot more challenging off-road than what I’m envisioning for myself. It’s the “go anywhere” set-up I like (acknowledging you’re still on a 450 lb + machine).

Thanks for the quick reply, SD.
And the link to the Revizilla story was a treat. Gives me some ideas for future mods if my actual riding comes close to my fantasy rides.
I'll look around for the John Wesley thread. If I find it I'll let you know.

Hay Ron. Here’s John’s off-road project. https://advrider.com/f/threads/r-75-mods-for-rocky’s-mtn-passes.1363380/.

Good find.
I got hung up reading some of his other post. Seems he likes to ad mods and knows his bikes.

1/2" is deeper than you think. The pick up wants to be on the bottom of the oil puddle to get colder and less frothy oil.

You can always add the extension later.

Ah, got it. Thanks, Disston. Any part # info on the extender?

Sump pickup on my '86 G/S


Sump pickup extender lowers the intake with the holes so it is closer to the bottom of the deeper pan.

When you drop your old pan, measure the distance the sump pickup extends beyond the end of the motor and then measure how deep the original pan is at that location. Next, measure the '93 pan at the same location. The difference is the amount the sump pickup should be lowered.

I put the Siebenrock bash plate/deep pan on my G/S and it came with a new, deeper pickup. Normally it would just be a piece that fits between the old pickup and the tube above along with some longer bolts.

FWIW, I kept the original dipstick which means my motor is carrying around almost another liter of oil.

Excellent info, MP. Thank you.