CB400 Super Four oil leak and blue smoke

[djrichieb]

Hi All,

i have a CB400SF and its leaking oil from the oil filter. It looks like some think had hit the oil filter like a stone from the road etc and caused quite a leak. I noticed it on my way home from work the other day. I have a new oil filter but im yet to fit it. Onto my question, it was kicking out quite an amount of blue smoke from the exhaust on the way home. There was oil in the bike when i arrived home but it was dripping out at quite a rate. Im woundering if the oil rings could have gone? The oil light didnt come on but i didnt have chance to check the dipstick after drying up the oil then having to dash out.

Thanks in advance for any replys

Richie
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Rides: Honda CB400 SF (ART can) - Citroen Saxo 1.1i SX

[garyd]

Maybe just oil thats got sprayed up onto the zorsts
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CRF230 all you need

[Finglonga]

If there is lots of oil in your air-box then there is quite a bit of blow through on the rings. Just heavy smoke could be valve stem seals but that wouldn't put oil in the air-box.
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Andy Sez....
F.Y.Y.F.F.

[cestrian]

Blue smoke would be indicative of a rich fuel/air mixture, not burning oil.

[djrichieb]

it could be garyd as the oil filter is leaking from the front and if you look at this pic it is right next to the exhaust at the front of the engine..

I havent looked in the airbox Finglonga but ill double check when i have a chance to..

ar right cestrian. It only started happening since the oil leak so i presumed oil burning (from my days in 2T motoring).
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Rides: Honda CB400 SF (ART can) - Citroen Saxo 1.1i SX

[StealthDJ]

You were right first time - blue smoke is oil. Black smoke is running rich and white smoke is a blown turbo

I think you're chasing ghosts until you sort the oil leak. Replace the filter, and clean/gunk/degrease all the front end and exhaust downpipes. Then run it for 50-100 miles or so to burn the rest off.

After that, check for your blue smoke out of the ends of the exhaust pipes. If the smoke still comes from the front, you have another leak somewhere. General rule of thumb is smoke at idle or under power = knackered rings or bores. Smoke on overrun (well, on opening throttle *after* overrun) = valve stem seals. So it might be easier to get someone to follow you to work it out.

So basically, change the filter and clean it first. Then see...
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Current garage: VFR800 FI-W | RD500LC YPVS | SV650 K2 | MZ TS250/1 | MZ ETZ251 | BSA WDB40
Previous notables: H100 S2 | CB250NA/B | CB250T | GT250X7 | Z650 B1 | SR650
Still owned, but long gone: RD250LC | CB750F2 SOHC | C50