exhaust smoke

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Whitey

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Jul 26, 2007
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I have a 631 Bobcat with a 2cyl. Deutz motor, it's hard to start when it's cold and when it does it smokes a lot, the smoke dissipates almost completely after it has run for about 10 minutes, but it still smokes a little, it used less then a 1/2 quart of oil after about 60 hrs. of use, I had someone look at it and he thought it might be blow-by. My question is, is this an exspensive repair and any idea how much? Thanks Whitey
 

Tazza

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Dec 7, 2004
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What coulor is the smoke
Being a deutz, repair will be VERY expensive sorry.
How does it run when started? You said its hard to start, have you tried hitting the excess fuel button on the pump and see how it starts? Mine used to fire up instantly when i hit that button.
You my be lucky and its injectors too.
As Shawn said, what colour is the smoke?
 

skidsteer.ca

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Jan 20, 2006
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It runs good when it starts, What is very exspensive?, and if It's blow-by what's involved in repairing it?. Thanks for the input, Whitey
Blow by is compression escaping past the piston rings into the crankcase. It lowers compression which leads to poor starting and usually excessive oil consumption.
The repair is to rebore or re liner the cylinders, new piston and rings, and generally engine that are worn enough to need this type of work need a complete overhaul.
The color of the smoke indicates the trouble spot in a diesel. Black is excessive fuel or lack of air, blue is oil consumption and white is anti freeze getting into the cylinders. Yours is air cooled though?
Ken
 

Tazza

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Blow by is compression escaping past the piston rings into the crankcase. It lowers compression which leads to poor starting and usually excessive oil consumption.
The repair is to rebore or re liner the cylinders, new piston and rings, and generally engine that are worn enough to need this type of work need a complete overhaul.
The color of the smoke indicates the trouble spot in a diesel. Black is excessive fuel or lack of air, blue is oil consumption and white is anti freeze getting into the cylinders. Yours is air cooled though?
Ken
The 2 cylinder Deutz are air cooled, great engine but rattle like no ones business.
As Ken pointed out, if you have low compression you will need new pistons/rings a re-bore and if you are that far in, you replace all the crank bearings. It will be rather costly, not sure how bad bit i would guess at a shop you would be looking at the 2-3K mark.
If you are really worried, get the compression checked. If its low worry, if not just run it as it is. Have you used the excessive fuel button on the injector?
White smoke also means un-burnt fuel. It could even be a faulty injector.
Just a few options for you.
 
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Whitey

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Jul 26, 2007
Messages
17
The 2 cylinder Deutz are air cooled, great engine but rattle like no ones business.
As Ken pointed out, if you have low compression you will need new pistons/rings a re-bore and if you are that far in, you replace all the crank bearings. It will be rather costly, not sure how bad bit i would guess at a shop you would be looking at the 2-3K mark.
If you are really worried, get the compression checked. If its low worry, if not just run it as it is. Have you used the excessive fuel button on the injector?
White smoke also means un-burnt fuel. It could even be a faulty injector.
Just a few options for you.
There is some sort of button on what looks like some kind of fuel pump on the front of the motor, I pushed it down, it seemed like it was spring loaded, but it didn't come back up, I sprayed WD-40 on it and it,s still in the down position, I haven't tried to start start it in fear I might have screwed something up. Any help would be greatly appreciated. Thanks Whitey
 

Tazza

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There is some sort of button on what looks like some kind of fuel pump on the front of the motor, I pushed it down, it seemed like it was spring loaded, but it didn't come back up, I sprayed WD-40 on it and it,s still in the down position, I haven't tried to start start it in fear I might have screwed something up. Any help would be greatly appreciated. Thanks Whitey
Thats your excessive fuel button.
Give the machine a bit of throttle, press the button and it will drop down. Crank the engine and it should fire rite up. Its totally normal for the button to click and fall down, but when it starts it will pop back up.
You have done NOTHING wrong, just start it. You will find it will blow a bit of black smoke but that will clear up quickly. The button just makes the pump squirt in LOTS more fuel to assist in starting. I found with mine, i hit the starter and the motor would turn over once and burst into life, blow a bit of smoke for a few seconds and then clear.
Any concerns just e-mail me, my address is in my profile.
 

Land-Tech

Well-known member
Joined
May 13, 2008
Messages
160
Thats your excessive fuel button.
Give the machine a bit of throttle, press the button and it will drop down. Crank the engine and it should fire rite up. Its totally normal for the button to click and fall down, but when it starts it will pop back up.
You have done NOTHING wrong, just start it. You will find it will blow a bit of black smoke but that will clear up quickly. The button just makes the pump squirt in LOTS more fuel to assist in starting. I found with mine, i hit the starter and the motor would turn over once and burst into life, blow a bit of smoke for a few seconds and then clear.
Any concerns just e-mail me, my address is in my profile.
Whitey, If outside temps are below freezing and I haven't plugged in the block heater and the engine has bad glowplugs or no preheat of some sort, a deisel will blow white smoke until it warms up. As it's doing this it will rattle and at least to me,make a a lot of unnerving noises.As they warm up they smooth out and then run fine.The old 6.9 and 7.3 ford pick-ups are bad for this if there are a couple of glowplugs burnt out. The 2 cycle detroits are really bad in cold weather but once they warm up it goes away. I was told that this was due to cold cylinder temp. Also its a real dirty white, if there is such a color and you will smell the unburnt fuel .Try warming it up by parking in a warm garage and see if it makes a difference.
 

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