Topic: Oil Sump Maintenance 400F

[grumpy56]

Hello all. Thinking of removing the oil pan on my 76 CB400f to clean the strainer. Bike has less than 7000 miles, but I don't know if it has ever been done. Oil in the sump when when I bought it was not dirty at all and am at about 1000 miles since I changed oil and filter. A few questions;
1) How do you get the three 10mm bolts on the exhaust side (OEM header) off/on?
2) Do those strainers ever get dirty? My original manual in one place says to clean the strainer at 6000 miles and in another place 12000 miles. Of course I may well be way beyond the 2 year periodic requirement , uhm like 47 years beyond.
3) Have a Nippon Machines gasket. They OK?
Thank you.


 

[BenelliSEI]

You’ll probably have to get the muffler off, before you can remove the sump. I’d bet the strainer will be very clean. Of so, clean the pan, use your gasket and button it backup.

 If a new strainer screen is available and reasonably priced, have one on hand (if you want to be really prepared). The rubber “ring” part of the original will be very brittle with age. Very easy to damage when removing and really difficult to reinstall…..

[bryanj]

Only seen dirty ones on neglected engines

[Nurse Julie]

I always manage to remove the sump pan on the 400/4's without removing or loosening any of the exhaust system. The pick up screens are usually not too clogged up but check carefully under the oil separation plate in the sump pan, a lot of rubbish can collect there.

[grumpy56]

Thank you all. Nurse Julie: How do you get to the three bolts on the exhaust side especially the one towards the back?

[Nurse Julie]

I have very small hands and just use a spanner. Admittedly, it's fiddly but I seem to manage OK and the bike is up on the bench, so good access.

[MauiK3]

Spanner is open end wrench from across the pond.  :-))
Would one of the Gear Wrench ratchet head box wrenches fit in there? Just wondering, I’ve never seen one up close.

[grumpy56]

Haven't found a way to get to those 3 bolts on the exhaust side. Can kind of get to the two front ones, but the third in the back is no-no, at least for me. Before I take the whole exhaust off, is it possible to remove the #1 pipe from the collector without removing the whole exhaust? The third bolt is just a bit behind the exhaust coupler so I may still not have good access, but thought I'd give it a try. Thanks again.

[Tim2005]

I don't think you'd separate that pipe, they are held in pretty tight and you wouldn't have the room to wriggle it to get it out. It should be pretty easy to remove the whole system, especially if you soak the cylinder head stud nuts with wd40 or something similar for a while beforehand

[Ozzybud]

Yes!  The number one pipe will come off independently of the other 3.

[grumpy56]

I just decided to take off the whole exhaust. The bolt on the #1 pipe at the collector connector was in a funky position and would have been a pain to loosen anyhow. Nice access to oil pan bolts now!!! Do appreciate all the help.

[BenelliSEI]

I just decided to take off the whole exhaust. The bolt on the #1 pipe at the collector connector was in a funky position and would have been a pain to loosen anyhow. Nice access to oil pan bolts now!!! Do appreciate all the help.

Good opportunity to give it a good scrub and polish too. How did the screen look? Spotless?

[grumpy56]

Haven't opened it up yet, hopefully within the next couple of days. Yep, cleaning as I go. Will post pics of the innards.

[grumpy56]

Got the oil pan off. Not much garbage in the screen, but there is sludge in the oil plan, more than what I was expecting. The gasket I have is a paper one, but the one I removed seems to be some sort of rubber material. Comments?

[BenelliSEI]

I’d remove the baffle and give evrything a really good scrub. Use the new gasket. Given the infrequency of this service, I’d use a light coat of gasket cement. My favourite is a light spray of the red Felpro product.

[Mark1976]

I’d remove the baffle and give evrything a really good scrub. Use the new gasket. Given the infrequency of this service, I’d use a light coat of gasket cement. My favourite is a light spray of the red Felpro product.

   I only use a gasket sealer on the pan itself, it's a pain in the arse scraping gasket material from the bottom of the engine case, but that's me. If ya ever want to save a buck down the road, make a copy (or 2) of the gasket now, again just what I do. Ya can always pass it on as well.

[Rayzerman]

Smear some grease on the side towards the engine, let soak in for a bit, wipe off the excess...... won't stick nearly as bad to the engine.

[BenelliSEI]

My thinking is since this is likely the first time off it +49 years, seal it up tight. Paper gaskets are not what was in there. Spray both sides and make sure it doesn’t leak. You won’t be in there again unless the engine comes out…….

[Mark1976]

My thinking is since this is likely the first time off it +49 years, seal it up tight. Paper gaskets are not what was in there. Spray both sides and make sure it doesn’t leak. You won’t be in there again unless the engine comes out…….

   They put an rubber seal up on the rocker cover, I sure wish they'd done the same thing for the oil pan. At least ya get a couple of open and close up cycles before you need to replace it.. My yamaha hasn't a gasket that I can think of on it... That bike hasn't leaked a drop since it was closed up over 2 yrs ago...

[grumpy56]

All I have is a thin paper gasket. The Honda P/N 11398-333-020 is no longer available. The original gasket was some sort of black rubber or equivalent and pretty thick. What's the suggestions regarding just wetting the paper gasket with oil and slapping it on there or use some sort of sealant?

[dave500]

a lot of modern pans n sumps dont have a gasket at all,just decent silicone from the factory,if your not heavy handed Id be using say jb weld black meant for pans etc,or cut a new gasket by hand is doable.

[Mark1976]

All I have is a thin paper gasket. The Honda P/N 11398-333-020 is no longer available. The original gasket was some sort of black rubber or equivalent and pretty thick. What's the suggestions regarding just wetting the paper gasket with oil and slapping it on there or use some sort of sealant?

   Personally, (and you do as you prefer) I buy gasket material that's thicker, use what ya have as a template. Seal it on one side, both sides or neither, up to you... I've never encountered a leaky oil pan on a 400f, plenty of leaking head and cylinder interfaces...

[scottly]

I always installed stock paper gaskets dry, or in some cases, like 750 cam cover gaskets, I sometimes glue the gasket to the cover. I've re-used stock gaskets several times on 750 alternator, shifter, and clutch covers.

[dave500]

Ive also reused gaskets on all sorts of things,if its in good shape not torn or distorted itll be good to go,Ive reused head gaskets on 500/550 fours on a couple of motors all good,your results may vary!

[grumpy56]

Can't use the original gasket and can't ask much more than almost 50 years on it!!! I think I'll just try the paper one with a bit of oil on it and see if it holds up before putting everything back together.