Britbike forum Forums British motorcycles in general British motorcycles in general MAP oil filter - hose size problem

The oil lines on my BSA are 5/16", but the spigots on the oil filter are 3/8". I can't change to 3/8" hose, because all the fittings on the bike are 5/16". It looks like the fittings on the oil filter are not removable.

I can get the 5/16" hose onto the filter, but it's a "stretch" (literally). It's not pretty but I guess it'll work.

Is there some other solution to this problem that I'm not seeing?

(BTW, the blue is masking tape. The bracket will either be painted black or remade in stainless steel.)

I usually just use NAPA fuel hose, I haven't ever damaged a 5/16" hose by working it onto a 3/8 fitting. At least never damaged one that I could tell, and that stuff needs changed every few years anyway. When working conditions are tight I use some vaseline and a shot from my heat gun.

P-80 is the way to do this. Google p-80 and get a sample.

Ok, I know about P-80; we have some at the shop. Thanks, I hadn't thought of that. I used slightly diluted Dawn to get the hose on, but that doesn't do anything beneficial for the hose.

Hello MarkZ,
I have one of those filters for a project but still without fitting. I bought it several years ago and I do not remember the way the hoses go. Can you enlighten me?

Thanks

Have you had to cut away the tool tray Mark to stop the hose fouling?

The only thing I can say about 5/16 hoses on 3/8 pipes is that I had to do this with the hoses I have on my A65 now. The inlet as we all know is 3/8 on the later bikes however the hose I bought was actually metric 10mm and not the 3/8 as stated (which is about 9.5mm) it was almost impossible to stop the leak. The smaller hose 5/16” may have been 8mm but 5/16 is closer to 8.3mm so it was a decent fit to start with. In the end I used the excess hose from the 5/16 /8mm for the inlet as well. Just warmed it up in a cup of boiling water for it to fit. Or as Leon said, use a heat gun to soften it.

So Nick, do they make those fittings 3/8" on one end and 5/16" on the other? If so, that would solve my problem nicely.

Mark,

If you look at more than the one picture and use the drop down menu, you will see that they do.

John I've heard you suggest that before but...

From the IPC website:

"Samples may be requested for larger-scale industrial or commercial applications and are not available for general or household use"

Amazon has small dispensers at @$9.

well, here's a liter for fifty bucks on eBay.

P80 on eBay

this is an excellent deal for P80, if its the real thing. i buy mine from apparent one-off liquidation sales like this. i got a half quart once for about twenty bucks, and then a liter for about twenty.

The bottom, or center spigot on the filter is the inlet (from the engine). The side spigot is the outlet (to the reservoir).

I have a two-pipe oil junction, and the rocker feed is off the oil tank. This makes my installation simple.


I didn't/don't have a tool carrier on this bike. The "bracket" you see is just a flat piece of stock and two L brackets. I did have to work around the lower frame lug though.

Ironically, as I was reading the instructions to answer reverb's question, I noticed that the supplier's prescription is to use the passenger peg mounting bolt. That would have been much simpler, but I did want to cover that area below the oil tank, since I don't have side panels on this bike either.

Got it; thanks. Ordering...

NAPA sells a rubber lubricant also. I've never tried P80, but the NAPA stuff works well. I forget what I paid for a jug but it was no where near $50 for a liter.

A liter should cost around $20.00.

Since we're on the subject of P80, I'll take the opportunity to repeat my testimonial regarding the use of this stuff on fork gaiters. It's been a few years now since I've been using it, and the gaiters are holding up very well.

As to my original query, I've ordered barbed brass "reducing" fittings, 3/8" to 5/16". They're coming from China, so I'll be waiting a while for them, but that's ok; I'm not planning to install the oil filter until the riding season is over. For appearance's sake, I'll first try them without clamps. (There WILL be clamps on the oil filter spigots though.)

Thanks NickL and Jon W. for the tips on where to find these fittings.

...regarding the fitting; you would do that in a late in no time...no need to wait for China men.

Assuming you meant to type "lathe": Right, but I don't have one. That's ok, I'm not in a rush to install this filter; I'm waiting until this riding season is over, which looks to be soon (I'm not a cold-weather rider), and I still have to paint the parts I made.

Did you see my response to your question about the inlet vs. outlet? It got kind of buried above.

Sticking a narrow hose on a slightly large end fitting can risk small shavings of rubber inside the hose, so be careful.
I have used a mug of hot water often, one quick flick throws any trapped water away and the hose is malleable for a few mins

Hi Mark; sorry; yes "lathe".
Yes; I read your response.

Thanks

Anglo, read on; I'm getting inline "reducing" fittings to make the transition from 3/8" to 5 /16", so I won't have to stretch the hose.

i find that odd. i installed 4 of those from map one on a '65 t100sr,a '54 bsa b33 and the other two were on a65's,its been 15 yrs but i think theres a screwup somewhere and a call to map is in order.i can assure you they were ALL 5/16'' i.d. hose connections.feel free to quote me.

Judging from the answers I get on the BSA forum, I thought all you BSA guys had lathes. Maybe that's just the Aussie contingent?

What you mean "you guys?" I'm just an amateur enthusiast who has owned BSAs for a very long time. I don't paint (except for little stuff), I don't weld, and I don't do machine work, except for what I can do with a band saw, a belt sander, and a drill press. Somehow I've always managed to avoid or contract out all that stuff.