Author Topic: oil consumption  (Read 1736 times)

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Offline haill

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oil consumption
« on: December 01, 2009, 04:01:02 PM »
what is normal oil consumption after rebuild on a 1971 CB500/four.   honed the cylinders that were within tolerance, new rings, valves were machined and lapped new gaskets etc.
the bike  had the first oil changed around 250 miles found a cloth type fibrous substance in the oil pan which I'm thinking is my clutch plates? or lots of left over fuzz from cotton cleaning rags?
the plugs have a nice brown tan colour and the bike sounds/runs great but does burn about a 500ml or 16Oz's in about 6 tanks worth of gas. or 1000 miles?
is this normal oil use? when first broken in the bike had carburetor troubles which took me some time to fix so it spent time idling, after that ran it in by lagging motor and running hard up hills etc. the bikes motor is about month half old since rebuild. it does leak some from the oil pan seam which i have torqued tighter last night. there are no oil drips on the shop floor, seems to weep  when hot.
« Last Edit: December 01, 2009, 04:48:01 PM by haill »

Offline simon#42

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Re: oil consumption
« Reply #1 on: December 02, 2009, 02:17:05 PM »
not sure about a 500 but that is the same oil consumption as my 750  [ and now 836 ]
recently did 4000 miles in a fortnight [ sunny portugal !] and used just under 2 ltrs

Offline haill

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Re: oil consumption
« Reply #2 on: December 03, 2009, 04:21:10 AM »
was concerned that maybe the cylinders had glazed for this is/was my first complete rebuild.
have read that the consumption goes down in time as well after things had thoroughly worked in.
it's been 1000 miles will keep my eye on the oil level to see if it improves.
not sure what glazed cylinders react/look like when running. does oil burn in the exhaust gas making it white, coat spark plugs and disappear at the dip stick end...

Offline Toxic

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Re: oil consumption
« Reply #3 on: December 03, 2009, 04:38:10 AM »
after that ran it in by lagging motor and running hard up hills etc.

Who suggested it was a good idea to break in a motor this way?  I don't want to discuss the correct way to break in a new motor but lagging a motor is the last thing you want to do.

Do a search on tips for breaking in a new motor.  There are endless sometimes heated discussions on the proper way to do it.

Oil consumption will lessen, so bottom line is I wouldn't do anything about it now.  Just monitor it.

...And stop lagging the engine

Offline haill

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Re: oil consumption
« Reply #4 on: December 03, 2009, 04:44:01 AM »
lagging might have been the wrong term what is it call when you close the throttle down quickly after running it open.
read it places lots of compression on the piston/rings and helps them seat.
wasn't driving the bike around in too big a gear if that's what you thought...

Offline Toxic

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Re: oil consumption
« Reply #5 on: December 03, 2009, 04:55:53 AM »
Ah yes wrong term.  Lagging would be as you describe "chugging around in too big of a gear"

Are you blowing alot of oil out the tail pipes? If so what color and what does it smell like?

Ride it enjoy it and see if the consumption improves.

Offline bryanj

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Re: oil consumption
« Reply #6 on: December 03, 2009, 08:06:44 AM »
Shutting the throttle like that causes a high vacuum in the cylinder and drags oil past the rings and stem seals so it will use more riding that way.
Way back when if you had to top up the oil between 1,500 mile oil changes it was using too much
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline haill

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Re: oil consumption
« Reply #7 on: December 03, 2009, 11:06:34 AM »
 the exhaust is clear and smells good. the plugs are tan coloured but it is using oil nun the less.
some loss might have been from the lower oil pan gasket which was/is leaking torqued it tighter but haven't rode the bike since.
there was oil that coated the centre stand and weeps out of the oil pan seam. new gaskets allround too. the rest of the kit worked beautifully "Royal Industries" [NP] this particular one thou is giving me some issues. Have been enjoying the ride, it's rural here and there's some beautiful twisty roads that run along the ocean.
very little traffic this time of year too since most of the tourists/summer residence have left for the winter.
Closed the throttle quickly only for the first ride after getting it sorted.
regards