Author Topic: Bewildered ! Help ! (thick blue smoke)  (Read 3836 times)

Offline tomtit

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Bewildered ! Help ! (thick blue smoke)
« on: 17.10. 2014 01:45 »
Got the bike finished a couple of weeks ago all was fine when I noticed an oil leak on the bottom of the inner timing cover. Pulled of the outer and inner covers cleaned and new gaskets fitted. Put it all back and a day or so later noticed I still had a leak from the inner cover so off the covers came again but this time and I somehow managed to let the idler gear drop out. I set the timing marks for the gear with the dot and dash lined up at TDC and put it all back together again this time with different gasket cement. This is where I become the village idiot, while putting back the outer timing cover I decided to replace the rocker box gaskets as I thought the bike's being lying up 9 years with the heat the gaskets may start to leak. After removing all the old cement and gaskets and replacing with new gaskets I put the rocker box back on using the comb tool for the pushrods.
Now here is the problem, I started the bike and there was thick blue smoke coming out of the exhausts, the right side was really bad. Stopped the engine immediately and pulled off the rocker box again, on inspection everything looked OK but had to leave it for a few days.

Fitted the rocker box again this morning and making sure Pushrods were in place correctly reset the tappets and checked the valves and pushrods were working OK then started the bike up and lo and behold it's burning oil again and not sure if there are bent valves or what's going on so hopefully some of you Guru's may be able to shed some light on this.

1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia

Offline Flatboy 1950

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #1 on: 17.10. 2014 05:32 »
Crank case is flooded with oil ( wet sumping) , nothing to do with the top end of the motor.

Online RichardL

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #2 on: 17.10. 2014 06:42 »
Maybe, explaining serious oil leak at timing cover?
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Offline tomtit

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #3 on: 17.10. 2014 08:02 »
That's one of the first things I thought of, took the sump cover off and very little oil came out so don't think it's wet sumping. While working on the timing cover leak on the second attempt I actually drained the oil tank and let the oil drain out of the timing side overnight. I put the covers back on and put oil back into the tank then kicked it over half a dozen times with the plugs out to get the oil circulating.

Thanks anyway guy's for the thought, still none the wiser.
1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia

Online beezermacc

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #4 on: 17.10. 2014 08:58 »
Starting from basics, if a bike is burning oil it can only come from two directions, either down the valve guides or past the piston rings. If the bike has wet sumped the potential for oil passing the rings increases and the additional bottom end pressure tends to force oil past the rings but if it doesn't clear after a minute or so the wet sumping is probably not the problem. As the bike has been standing for a long time I would suspect stuck oil rings. A compression test might give a hint if other rings are stuck as well. Another 'left field' possibility, have you somehow managed to get oil in your fuel?! And actually that's the third direction oil can get into the combustion chamber, through the carb!
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Offline tomtit

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #5 on: 17.10. 2014 09:54 »
Thank you beezermac, my apologies as my earlier post stated the bike was lying up for 9 years as it was but I had got it up and running with no problems to speak of. When I had it running there was no oil burning it ran really good if anything it was a bit rich, concentric carby fitted. It's only since removing and replacing the rocker cover the problem has arisen, when I fitted the rocker cover the first time I did not slacken off the tappets (Idiot me) so maybe I damaged/bent a valve but I can not see any of the valves sticking as when I kick it over without plugs in all the valves seem to be working OK?.
1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia

Online RichardL

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #6 on: 17.10. 2014 13:08 »
To have bent a valve, it seems you would have to have put the idler in incorrectly, considering things were fine before your work. Haven't experienced this myself, and could be off base, but perhaps a seriously bent valve displaces the guide then gets free of the guide, giving the appearance of normal valve movement. (All guesswork and thought problems, right now.)

Less dramatically, did you recently replace your banjo bolts with ones having holes that are too large?

It could be a completely coincidental occurrence of simultaneous problems. A compression test is the very next thing you should do. If bad, shoot some oil in the cylinders.  If no help, then the problem is probably not related to rings. [Sorry, if this is (as they say on the Jolly Ol' side of the pond), "teaching grandma how to suck eggs".]

Richard L.
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Offline tomtit

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #7 on: 17.10. 2014 20:36 »
Thanks Richard, no I used the same banjo bolts, I lined the idler gear with the dot on the crank and the dash with the dash on the cam gear, piston at TDC tappets loose on R/H side. When kicking over it still needs the same effort to turn over, if a valve/s were bent surely compression would escape and I should feel it on kick over as both cylinders are blowing smoke just the right seems thicker/heavier also the engine is running lumpy and cutting out, won't tick over as before. *ex*
1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #8 on: 17.10. 2014 20:52 »
Good one Richard, down here it's called "blowing wind up your ar$e"
On 1st read of this I was thinking slightly bent valve, probably inlet. If the motor is turned over without the idler in place the cam might have a valve open and turning the motor will kiss a valve. Another thought is the timed breather in the right spot and the cork of the right thickness.
Cheers.
Just saw your post tomtit, check your breather.
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Online chaterlea25

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #9 on: 17.10. 2014 21:35 »
HI Tomtit,
Did you fit the breather and cork washer correctly when you had the timing covers off??

Have you ridden the bike much since its recommision ??
Siezed rings will seal initially  and break up after some use  *sad2*
I have seen this happen on several occasions

John
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Offline tomtit

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #10 on: 17.10. 2014 22:31 »
Thanks Musky & John, initially when I tried to fix the oil leak put everything back started the bike and no problems but noticed the oil was still leaking from the inner case. 2nd time I stripped the timing case and then decided to replace the rocker box gaskets ( If it ain't broke don't fix it) and that's when the problem began so it looks more like the top end is the problem. I don't have a compression tester so going to see I can borrow one, the bike was going so well and then I had a Homer Simpson moment and screwed it up.  *pull hair out*
1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #11 on: 17.10. 2014 23:30 »
John has a point about old rings breaking up after a period of use. Comp test will tell.
You could have had a pushrod sitting on the edge of a cup, the piston kissed a valve and popped it back in the cup. Check your valve clearances again. If one or more has opened up significantly, that's it.

Cheers
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Offline Topdad

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #12 on: 18.10. 2014 09:51 »
This is a bit wierd and as most solutions seem to have been mentioned what about an dodge we used to use for smoking motors ,redX . Run your motor and squirt some neat redX in via the carb whilst revving her to keep the plugs clear ,don't do it in the shed or while the wifes washing but it may clear the rings etc and don't think it would hurt .i once bought an old side over inlet Landie which wouldn't run on 4 and smoked its head off used this and got 14 mths solid service out of her,Bob.
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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #13 on: 18.10. 2014 11:10 »
Sort of like the old re-ring and de-coke. Water to de-coke and bon ami to re-ring  *eek*.
Cheers
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Offline tomtit

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Re: Bewildered ! Help ! (thick blue smoke)
« Reply #14 on: 18.10. 2014 21:27 »
Musky I think you may have hit the nail on the head so to speak in your earlier post, in my stupidity (or Senility) I did turn the crankshaft over with the idler gear out when I was initially setting the timing and as you said probably kissed one of the valves so looks like best option is take the head off and check the valves/guides etc.

Thanks for the input Bob but I think I'll have to bite the bullet and strip the top end off, I was just hoping it was something simple and maybe someone here had a magic solution. Thanks again to all who helped with advice it was very much appreciated.

Just adding photos of how the old girl looks since I converted her from a rust bucket.
1950 A10 Golden Flash.
03 Yamaha V Star 1100.

Australia