Modern Vespa

I want to add an oil sight glass to my oil pan. Is there any reason why a standard air compressor sight glass won't work? A replacement oil pan with sight glass is $150. I can buy the sight glass and matching tap for about $25 on Amazon and install it myself. I have a small machine shop, so I can machine a flat on the pan and drill and tap the hole. If you don't think this sight glass is up to the task, can you recommend one?

You would also need to cut the oil pan 'fins' to accommodate it. I doubt you would achieve the finished look of the purpose adapted oil pan.

Machining off the fins would be part of creating the flat for the site glass to seal against the pan. Not a problem.
My biggest concern is whether the air compressor site glass can stand the heat of the Vespa motor. My guess is the air compressor oil does not get as hot since it runs intermittently.

What got me thinking about this is I was reading about the sight glass pans on the Scooterwest website. It says a company in Germany machines the standard oil pans to accept the sight glass. I figure if they can do it why can't I. They probably buy the standard pans in bulk from Piaggio.

Why not contact the manufacturer of the sight glass and ask what the temp rating is?

Look at this.

https://www.escopro.com/visual-oil-analysis/3-d-bullseye-oil-sight-glass/3-d-bullseye.html

Good suggestion... It wasn't easy tracking them down on Amazon. Thanks.

I like the idea!

If you go ahead with it, would you please share photos of the process?

From a DIY perspective, how critical is getting the glass location exactly right for accuracy reading purposes? Or is it all a generalization anyway?

Thanks, I definitely will take some pictures of my setup. Right now I'm thinking the best way for me is to use a rotary table on the vertical mill.

I was wondering about that at first, but it seems like "close" will show an oil level and then comparing that to the dipstick level will determine the correct level on the site glass. It might not be right in the middle, but that shouldn't matter. I think eyeballing the location in relation to the fins should be close enough.

I'm with Berto. Go for it, take photos along the way, and show us how you got there. In my opinion, the step by step project posts on MV are the most cherished.

Worst case, you need to buy a new oil pan.

Or you could by a purpose built pan from ScooterWest and reverse engineer it. Then, sell the purpose built pan to recoup your money. No guessing involved.

That's a good idea, but everyone wants a bargain (me included) so I would probably lose 25-50 bucks. If the location wasn't so obvious in relation to the fins, I would consider that. Maybe someone who reads this will measure theirs and post some numbers.

FWIW, I bought mine from SIP for a bit over US$100 in March, and had my dealer install it at Thelonica's first (600mi) service. Mind you, I did also order a Euro-spec Flyscreen and crashbars at the same time, so in terms of shipping charges it was more worth my while. (They also had everything in stock - not something to be taken too much for granted right now.)

I wish that the sight glass equipped oil pan had about 250cc more capacity.

No, this is a different company from the one you showed.

Modern Vespa is a unique beast indeed. If I'm following this correctly, you have owners of $9,000 scooters brainstorming on how to save $100 by modifying the oil sump keeping their fingers crossed against catastrophic oil sump failure on the freeway 200 miles from home? Is that accurate? You don't find posts like this on Modern Buddy.

Right. I was looking for the manufacturer of the one I saw on Amazon.

If one is to have a $9000 scooter, you need to offset the cost of other projects else ware!

Are we not the same group that talks about less expensive motor oils and coolant ad nauseam in order to save just a few bucks?

This more of a conversation about ingenuity!

Have we had the "does removing cooling fins from my oil pan void my warranty " discussion yet?

Yes and the one I found is a different type of sight glass Looks like easier to read. As long as it doesn't stick out past the fins, it might be a good alternative.

I've laughed at the same - on the Burgman forum...
Guys cutting up $2 hardware store furnace filters to use in their $10,000 scooter!
Others saying dirty oil filters catch more, so double the service schedule. etc.!!

O.S.

FYI

Buchsenfuchs.com is the maker of these oil pans with sight glasses and they sell to SIP and to Scooter West (maybe via SIP?)
https://www.buchsenfuchs.com/shop/vespa/

Here's Peter Thoma's (Buchsenfuchs) thread when he first made and released them
https://www-vespaforum-de.translate.goog/viewtopic.php?f=16&t=53305&sid=23ac84f66109d84db5ce7791265971cf&_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=sc
(original in german https://vespaforum.de/viewtopic.php?f=16&t=53305)

If I were a GTS owner I would start a GoFundMe where we all pitch a few bucks to help fund this project and make it a communal thing.

Armed with a very expensive mill and rotary table, it seems silly to pay for a new sump
Go for it.

I see it more as an interesting and challenging project than saving a few dollars. There's a lot of satisfaction working something out in the shop.

The dollars "saved" are what you tell your wife to justify the at-home machine shop!

If it works, a lot of us will be asking for your address this winter so you can convert ours as well. We hope to see a minimal fee too!

Agreed. I love challenging projects, especially ones that don't risk me sliding under a gas truck and tasting my own blood.

That's a great thread, and there's a lot of good information in there. I am still reading it. Thanks! I admit that my first motivation was to save money, and I can see the irony and humor in that. But challenging projects are what keep life interesting, so I agree with Berto on this one. It's nice to save a few bucks, but the real fun is in figuring out how to do it.

Good luck with the challenge, we look forward to seeing the finished result. If it's a success I'll post you mine

If I were in your shoes. I'd be posting after the fact. I miss being able to make my own scooter parts/mods at work on weekends. I can't have a small shop in the condo.

That's a fair question. Is the warranty voided for everyone who has already replaced the oil pan with the sight glass pan?

I wouldn't give warranty a second thought. But I modified the entire fuel system on my brand new Subaru WRX STI to run 85%+ ethanol before it was a month old. I don't put a lot of value on manufacturers warranties.

This looks like a fun project.

-Craig

I'm gonna miss that some day too. The purpose of starting this thread before the fact was to learn more about sight glasses. From what I have seen, the best ones have a metal body (machined aluminum, brass, or stainless steel, not pot metal or plastic), and a real glass window. McMaster-Carr sells one that is rated to 210 deg. but it says it's for hydraulic fluid or diesel fuel...not specifically motor oil. Does anybody know how hot the hpe oil pan gets on a hot day and long trip?

To the point of risking a $9000 Vespa to save $100...If I buy the oil pan with the glass already installed, what guarantee do I have that it won't fail and ruin the motor. Would the company in Germany that made it replace my scooter? I don't think so. They say clearly to install at your own risk. So it comes down to the quality of the sight glass and whether I can machine a flat on the pan, drill and tap the hole, and screw in the sight glass with thread lock. If there's more to it than that, please let us know.

You're not risking the whole warranty. In the USA, your modification must be shown to have caused a failure before they can refuse to cover it. So, for example, if the glass broke and you dumped all the oil and ruined the motor, they would not warranty a replacement. But if your motor had an oil related failure because the oil pump took a dump, they would have a hard time arguing that was caused by your sight glass modification (they might try). And any other warranty issues, electrical, paint, etc., would still be 100% covered as your modification has absolutely nothing to do with those items.

-Craig

That sight glass seems more robust than the comparatively cheap pressed-in unit I replaced on my Ducati.

This one shows 248 deg. f.

https://www.amazon.com/dp/B097T7X4WJ/ref=sspa_dk_detail_1?pd_rd_i=B097T7X4WJ&pd_rd_w=ryB7m&content-id=amzn1.sym.24b0b161-2d2e-40f8-8233-013eb186b34a&pf_rd_p=24b0b161-2d2e-40f8-8233-013eb186b34a&pf_rd_r=CSQAYAGSNYT1D8C0X360&pd_rd_wg=P6efl&pd_rd_r=bc8ea6a0-f786-4fe2-9571-6f6d1334d68c&s=industrial&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyVU1DQjAwMlFVSU5QJmVuY3J5cHRlZElkPUExMDI3ODM5MUNMMFFXWEVWNlM1UiZlbmNyeXB0ZWRBZElkPUEwNzA1NjI4NzJHTVhPM1AwNFo2JndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1

That one looks really nice. Thanks! The others I have looked at have straight BSP threads with an "O" ring seal. This one uses tapered NPT threads with no "O" ring. I don't really know which would be better. I know with NPT, you have to match how far in you tap with the depth you want the threads to screw in. That's not really a problem, and the NPT threads with the proper sealant might make for a more secure mounting. What do you think?

They don't give the OD of that Amazon unit. From what I have seen on others, 3/4" thread will make the overall OD about 1.25" which might be too big. From eyeballing pictures online the glass on the Vespa seems to be about 5/8" diameter comparing it to the fins on my pan. I have been thinking that the glasses with 1/2" threads might be more the correct size, but if they have only 1/2" diameter like the McMaster unit above, that's kind of small. The bigger the glass, the better up to the point where the overall OD doesn't fit right.

It would be really helpful if someone with the sight glass pan would post some measurements...the diameter of the glass, and the overall OD. Thanks so much!