Author Topic: Engine oil use?  (Read 3298 times)

Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Engine oil use?
« on: May 27, 2019, 08:55:18 PM »
Evening all. Sorry got another question. I’ve had my 400/4 a few months now and was wondering how much oil its normal to use? I estimate that I’ve used about 1.5 litres and riden about 800 miles. Is that about normal or have I a problem? There’s no obvious oil leak that I can see and haven’t noticed blue smoke out of the exhaust.

Offline K2-K6

  • Grogu
  • *
  • Posts: 5236
    • View Profile
Re: Engine oil use?
« Reply #1 on: May 27, 2019, 09:45:16 PM »
No not normal.  That's a fairly chunky usage for that mileage so it must be going somewhere.

Initially and pragmatically,  if it's been sitting not used for significant period of time it's possible that the piston rings are gummed and not working as they should.

Be scrupulous about checking oil level,  certainly to make sure you don't run low and cause damage.  Run for more mileage and assess to see if it changes.

Could consider treating with redex into petrol to find out of it can improve.  The theory here is to reduce gumming and residue that could be stopping piston rings from sealing properly.

Failing that,   a compression test would be useful in giving an insight into bore and compression ring effectiveness.


Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Re: Engine oil use?
« Reply #2 on: May 27, 2019, 10:06:05 PM »
Thanks K2-K6. Thanks for your reply. I have used Redex once before so will try a few more shots and see if that does the trick. Am I right in thinking I should check oil level after running the engine for a couple of minutes?

Offline Trigger

  • Grogu
  • *
  • Posts: 8434
  • Engines built on reputation, not advertising.
    • View Profile
Re: Engine oil use?
« Reply #3 on: May 27, 2019, 10:07:58 PM »
Nope, you should check the oil when cold and on the centre stand  ;)

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
  • Grogu
  • *
  • Posts: 8206
    • View Profile
Re: Engine oil use?
« Reply #4 on: May 27, 2019, 10:11:54 PM »
Wow, that is a lot of oil. Have you looked at the air filter and foam in the bottom of the air box? If it's really oily, it could be a sign of raised crank case pressure suggesting rings are stuck or bores are worn. Like all these old bikes / engines, they do burn a bit of oil so some topping up regularly is required but not that much.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Re: Engine oil use?
« Reply #5 on: May 27, 2019, 10:14:55 PM »
Ok thanks. Will have a look tomorrow at the air filter. Thanks again for your speedy replies.

Offline dave400

  • SOHC Expert
  • Posts: 370
    • View Profile
Re: Engine oil use?
« Reply #6 on: May 28, 2019, 07:45:38 PM »
Evening all. Sorry got another question. I’ve had my 400/4 a few months now and was wondering how much oil its normal to use? I estimate that I’ve used about 1.5 litres and riden about 800 miles. Is that about normal or have I a problem? There’s no obvious oil leak that I can see and haven’t noticed blue smoke out of the exhaust.

Blimey..I can’t remember ever having to top up oil on my 400, yours seems to have a problem if it uses that sort of amount I’m at about 20K miles with mostly original metal parts but new seals and other bits and pieces.......Dave

Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Re: Engine oil use?
« Reply #7 on: May 28, 2019, 09:45:11 PM »
Hi Julie. Had a look at the air filter and foam in the bottom of the air box. Seems pretty dry and good there ( to my untrained eye). Will try K2-K6 Redex idea and see what happens. Is it ok to still use my bike with this oil problem or is it likely to make things worse?

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
  • Grogu
  • *
  • Posts: 8206
    • View Profile
Re: Engine oil use?
« Reply #8 on: May 28, 2019, 09:54:19 PM »
Hi Julie. Had a look at the air filter and foam in the bottom of the air box. Seems pretty dry and good there ( to my untrained eye). Will try K2-K6 Redex idea and see what happens. Is it ok to still use my bike with this oil problem or is it likely to make things worse?
As long as you check the oil level and top it up regularly you will be ok but, in the longer term, as Nigel suggested, you really need a compression test to see what's happening. It may just be stuck piston rings. What you can do for now is put some oil down the bores, to see if it will free off the rings, (about 10 ml I think), when the pistons are not at top dead centre and leave it for a couple of days, then ride the bike and see if this has any effect on the oil consumption. If it is still using loads of oil then a compression test is definitely the next course of action.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
  • Grogu
  • *
  • Posts: 8206
    • View Profile
Re: Engine oil use?
« Reply #9 on: May 28, 2019, 09:57:42 PM »
Another thought....have you looked absolutely everywhere for an oil leak?
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
  • Grogu
  • *
  • Posts: 8206
    • View Profile
Re: Engine oil use?
« Reply #10 on: May 28, 2019, 10:16:59 PM »
My brain is still thinking 😀😀😀 Are you checking the oil level correctly each time. Cold engine, bike on centre stand, clean dip stick, put dip stick back in the hole, do not screw it back in, just have it resting there on the lip and check level. You say there is no evidence of blue smoke from the exhaust 🤔, have you had someone ride / drive behind you to confirm this? Either the oil is leaking out or burning out.......either way, it's coming out, we just need to find from where. Don't worry too much though, these engines are as tough as old boots and I'm sure you don't ride it like a maniac 😀😀😀
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Re: Engine oil use?
« Reply #11 on: May 28, 2019, 10:22:06 PM »
Thanks Julie. There is a weeping of oil half way down number 1 cylinder (what I would call the fin). Would that be enough to lose that much oil?  Please excuse my ignorance but when you say put oil down the bores does that mean remove the plugs and put oil down there? How do I know when the pistons are not at Top dead centre?

Offline Bradders

  • SOHC Member
  • Posts: 215
    • View Profile
Re: Engine oil use?
« Reply #12 on: May 28, 2019, 10:34:43 PM »
My brain is still thinking 😀😀😀 Are you checking the oil level correctly each time. Cold engine, bike on centre stand, clean dip stick, put dip stick back in the hole, do not screw it back in, just have it resting there on the lip and check level. You say there is no evidence of blue smoke from the exhaust 🤔, have you had someone ride / drive behind you to confirm this? Either the oil is leaking out or burning out.......either way, it's coming out, we just need to find from where. Don't worry too much though, these engines are as tough as old boots and I'm sure you don't ride it like a maniac 😀😀😀
I will get my wife to follow me tomorrow to see if it’s blowing any smoke out. I’m checking the oil as you say. My son always laughs at me as he says I ride like an old man😀. Thanks for your time Julie.

Offline Trigger

  • Grogu
  • *
  • Posts: 8434
  • Engines built on reputation, not advertising.
    • View Profile
Re: Engine oil use?
« Reply #13 on: May 28, 2019, 10:51:36 PM »
My brain is still thinking 😀😀😀 Are you checking the oil level correctly each time. Cold engine, bike on centre stand, clean dip stick, put dip stick back in the hole, do not screw it back in, just have it resting there on the lip and check level. You say there is no evidence of blue smoke from the exhaust 🤔, have you had someone ride / drive behind you to confirm this? Either the oil is leaking out or burning out.......either way, it's coming out, we just need to find from where. Don't worry too much though, these engines are as tough as old boots and I'm sure you don't ride it like a maniac 😀😀😀

I'm sure there was a thread recently saying we had got it all wrong on checking oil levels, should be hot, screwed in not cold on top of threads.

The way you describe is the way I always checked the oil levels Julie.


I have added the correct amount of oil to rebuilt engines and the oil level is spot on the dip stick without screwing it in.
The workshop service manuals state : The machine should be upright on a level surface, DO NOT screw in the dip stick, just rest it on the boss for the correct level  ;)

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
  • Grogu
  • *
  • Posts: 8206
    • View Profile
Re: Engine oil use?
« Reply #14 on: May 28, 2019, 11:05:59 PM »
If you are not too sure or don't feel too confident doing this, maybe consider taking it to a garage for them to do. But yes, remove all the spark plugs. I would 'feel'  the top of one of the end pistons through the spark plug hole by resting something like a screwdriver on the top of the piston to determine where in the barrel the piston is sitting, which would also tell me what position the middle two pistons are in. If the one you are checking is too high or too low,you need to turn the engine over until the piston you are checking is sort of half way up the barrel. Put the oil through the spark plug hole, so the oil will be going onto the top of the pistons and will gradually seep down the side of the piston and around the rings and just leave it like that for a couple of days. Put the plugs back in so nothing can crawl, or fall in. And make sure you dont cross thread the plugs, start them off with your fingers so you can feel them in the thread before using plug spanner. After a couple of days, start and ride bike as normal,it may smoke a bit to start with as you will be burning off the residue of oil on top of the pistons.
Any oil around the head or barrel fins means oil is getting out through a gasket or O ring somewhere. It may be a combination of the oil leak and burning some oil that is making you use the amount of oil you are.
« Last Edit: May 28, 2019, 11:14:53 PM by Nurse Julie »
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal