Author Topic: Smoking on start up.  (Read 1748 times)

Offline edboy

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Re: Smoking on start up.
« Reply #15 on: 10.05. 2016 17:41 »
from the problem arising since your excess smoking i would drain and blow out the return side of the oil tank with an air line as well as checking the p.r.v. is clean. you seem to  have excess crank pressure and too much oil in the crankcase with an uprated oil pump? is it tight on the 3 studs? but carb flooding at start up can cause smoking as well. how much oil if any is being lost to oil burning?

Offline Dean

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Re: Smoking on start up.
« Reply #16 on: 12.05. 2016 14:46 »
Hi Edboy.
She's not buring oil while running, only on start up. As Muskrat says. wet sumping is the most likely cause and with the sump drain plug out she is dripping a little. GRRRRR.
The odd thing (although it might be a red herring) is I am sure its only started since I stuck my finger over the return pipe hole in the oil tank to force oil up to the top end. I could not think why this would make her smoke the next day when I had taken her on a run after doing the oil trick (anyexcess in the top end shold have cleared by then).

So, I am debating two causes for wet sumping starting now:
1. A bit of dirt has got wedged in the anti wet sumping valve seat ( maybe leftover from recent machining).
2. The oil is syphoning back from the spin on oil filter because I've upset it with the back pressure of sticking my finger over the retrun hole.

I think I'll go and disconnect the filter to eliminate the latter.

If it turns out to be acute wet sumping I'll stick thicker oil in her. *eek*


PS I don't think its excess crankcase pressure as the problem is only on start up.
 But do I win the prize for the best excuse for excess crankcase pressure?
You see when I first put the engine together some years ago it would leak oil everywhere and smoke. I decided to check for a blocked breather and Bingo the breather passageway in the crankcase was blocked. A but of judicious poking with a bit of wire and the cause of the blockage popped out. It was a moth chrysalis! It must have got in there between me cleaning th cases and reassembling the engine.
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Online Greybeard

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Re: Smoking on start up.
« Reply #17 on: 12.05. 2016 15:13 »
If it turns out to be acute wet sumping I'll stick thicker oil in her. *eek*
What, like grease?

Offline Dean

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Re: Smoking on start up.
« Reply #18 on: 12.05. 2016 15:17 »
If it turns out to be acute wet sumping I'll stick thicker oil in her. *eek*
What, like grease?

Nah. I'll save that for the gearbox leak?
I was thinking more like going back to straight 40 for the engine.
Never tell people your troubles. Half of them are not interested and the other half are glad you're getting what's coming to you.

Online Greybeard

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Re: Smoking on start up.
« Reply #19 on: 12.05. 2016 15:36 »
I use Morris's SAE40 monograde

Offline muskrat

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Re: Smoking on start up.
« Reply #20 on: 12.05. 2016 21:46 »
You could try taking the oil pump off and using the long thin tube you get with WD type sprays poke it up the hole (feed to the crank) and push the ball back a bit and give her a squirt. It helped a bit with my plunger. Failing that you just take an extra 5 minutes every morning and drain the sump before startup. I do!
Cheers
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Offline Dean

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Re: Smoking on start up.
« Reply #21 on: 13.05. 2016 08:19 »
Great tip Muskrat. I'll give it a go.
Never tell people your troubles. Half of them are not interested and the other half are glad you're getting what's coming to you.

Online Butch (cb)

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Re: Smoking on start up.
« Reply #22 on: 13.05. 2016 08:44 »
I gave up on 20/50. Going fine on straight 40.
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Offline duTch

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Re: Smoking on start up.
« Reply #23 on: 13.05. 2016 08:51 »
 
Quote
I use Morris's SAE40 monograde

 Geez, I hope Morris is ok with that *eek*
 
 and, Geez (again) Deano, there's some places fingers don't need to go *conf*, I guess this is one of them. Good idea in principle, but I think the rocker feed can only cope with so much anyway, and any more is superfluous. As I think that through, I have to wonder how any extra back-pressure can affect anything  *dunno* at this stage
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Online Greybeard

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Re: Smoking on start up.
« Reply #24 on: 13.05. 2016 09:40 »
Quote
I use Morris's SAE40 monograde
Geez, I hope Morris is ok with that *eek*
Should the apostrophe not be there?

Offline muskrat

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Re: Smoking on start up.
« Reply #25 on: 13.05. 2016 12:43 »
I've done the finger over hole thing a few times on both mine and they both have spin on filters to no ill affect. Most filters have a bypass valve so if the filter gets blocked the oil will still circulate (unfiltered).
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
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Offline morris

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Re: Smoking on start up.
« Reply #26 on: 13.05. 2016 21:35 »
Quote
I use Morris's SAE40 monograde

 Geez, I hope Morris is ok with that *eek*
 

As long as I get my fair share...  *contract*  *smile*
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Offline Dean

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Re: Smoking on start up.
« Reply #27 on: 18.05. 2016 21:13 »
Just to update. Still smokes with sump drained *sad2*

Its only on start up so I'll live with (well the neighbours will) till I get back from Italy then look at the top end.

 I can play with rocker thrust washers, and rubber bands at the same time.

BTW I have treated her to an Indian petrol tank since last posting and am very pleased with the quality and price.
Never tell people your troubles. Half of them are not interested and the other half are glad you're getting what's coming to you.

Online ellis

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Re: Smoking on start up.
« Reply #28 on: 18.05. 2016 23:15 »
Dean  Make sure the red oxide paint inside the tank does not start flaking off. Mine was bad so a hand full of assorted nuts and plenty of shaking got rid of the flaky paint inside. *smiley4*

Offline Steve.Carter

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Re: Smoking on start up.
« Reply #29 on: 19.05. 2016 06:47 »
These are the pistons that I fitted. They sorted my smokey engine immediately.
My neighbours were getting fed up with me *smile*

http://www.a7a10.net/forum/index.php?topic=9943.msg79634#new