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Discussion Starter #1
New owner, new member

Just bought a t-dub as a project. First time owner.



Minimal smoke at idle

Heavy white smoke with incresed throttle and load

starts easily and idles well

mild decrease in power

plug is fouled black

compression is good at 126

2001 with 9,400 miles and unknown service record

Just downloaded manual and plan routine service as first step.



Any advice and help with diagnosing this would be appreciated.
 

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How many miles have you put on it now with the white smoke??

The least expensive problem would be..... If the air filter is over oiled, first the oil will fill up the drain tube under the airbox. Then it will dribble down into the carb and cause smoke. I overdid it with k&n filter oil. Two years later I still have red oil dribbling into my airbox drain.








Is the spark plug carbon foiled from running rich or oil fouled from a bad seal somewhere?



Mor





You Might Try a leak down test.



The test is simple. Apply air pressure to the spark plug hole and listen. (make sure the valves are closed) You might have to take the exhaust pipe and carburetor off plus remove the oil fill cap. Other then that, just listen. You will need at least fifteen or twenty pounds of air pressure. Higher pressure will make the sound louder but too much and you will need to lock the crankshaft to keep the engine from turning. A hissing noise at the carburetor manifold indicated a leak at the intake valve(s). Hissing at the exhaust, leaking exhaust valve(s). Hissing at the oil fill or at the engine breather tube, leaking past the rings.







http://www.dansmc.com/leakdown.htm



http://www.motorcycl...t/leakdown.html



http://www.motorcycl...own-Tester.aspx A handyman can make one of these for about 20 bucks
 

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You have a black plug, because you have oil in your combustion chamber.



White smoke from a over oiled air filter?

Possible and you don't have to pay money to solve the problem.



But I know this problem from my own TW.

The valve steam seals!



A other option could be the piston rings -> the oil ring.

But I don't think, that the rings are the problem, because your compression pressure is correct.



Regards, Sebastian

Germany
 

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Discussion Starter #4
Thanks for the replies.

By history, the smoke is long term, for the one year the previous owner has owned it.

I was somewhat reassured by the good compression, I hope it is not piston and rings.

I will check the air filter, check the gas, and adjust the valves tomorrow.

I will look into adjusting the carbureator, and download the service manual.

I don't know how to check the valve seals, but will look into it.

I would have to borrow an air tank to do a leak down test, how much more does it tell you over the compression test?

I will post follow ups and more questions as I try to diagnose this.

I will need to learn as I go and appreciate your ideas.
 

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The bikes does have since one year this problem??????

Why has he (the previous owner) doesn't take care on the bike?

I would search for a solution, direct when I've noticed this problem.



To adjust the valves is always good, but it will not solve the problem (oil in the combustion chamber).



A other option for oil in the combustion chamber could be too much oil. So, check your oil level.

Oil can be pressed from the crank case vent into the air box and from the air box into the combustion chamber.



As you can see on the picture from Rich, that you have 3 possibilities for a leak (pressure test):

- valves

- piston rings

- cylinder head gasket



Pressure OK?

- If yes, all parts are OK.



But you don't have to make this air pressure test, because you've made a compression pressure test.

reference value: 128

your value: 126 (that's a good value)







I still think, your valve steam seals are the problem.

To change it will need round about 2 hours.
 

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Discussion Starter #6
today i wll start with the basics, change oil, filter, and plugs and adjust valves. get new clean fuel in the tank. and start going through the manual for other basic maintainence.



I haven't had time to research the valve stem seals. Is there a tutorial on site for changing the valve stem seals, can I do it in frame, and what special tools are required?



Yes, macbig2k1, it appears the bike has been neglected.



thanks again,
 

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Thanks Macbig,

I changed the oil, filter and plug and adjusted the valves and cleaned the air filter.

Still smoking and using oil. I may take it to a local mechanic this Friday.



I am debating whether to try to change the valves and seals myself. I have the downloaded service manual but no experience in engine work. I am tempted to pull off the cylinder head in the frame and just take a look. Some excellent tutorials on site but not on valve work.

Do you think I could replace the valves and stems myself with limited experience?

What parts would I need besides valves, valve seals and gaskets?



Thanks for your interest.

Danport
 

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Thanks Macbig,

I changed the oil, filter and plug and adjusted the valves and cleaned the air filter.

Still smoking and using oil. I may take it to a local mechanic this Friday.



I am debating whether to try to change the valves and seals myself. I have the downloaded service manual but no experience in engine work. I am tempted to pull off the cylinder head in the frame and just take a look. Some excellent tutorials on site but not on valve work.

Do you think I could replace the valves and stems myself with limited experience?

What parts would I need besides valves, valve seals and gaskets?



Thanks for your interest.

Danport


Valve seals are not that hard to replace. I just replaced my valves last week. I toke the cylinder head off and using a 6" C clamp and a piece of cut plastic pipe fashioned me a make shift valve compressor. Took 7 mins per side to take out and replace both vales and seals. Just be careful of the clips on either side of the valve, they are small and easily lost. Good luck and hope you find the problem.
 

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@ TWBARR

You've changed the valves but you haven't grinded then in?

At first: I am a bike mechanic.

And the second: If you want a perfect job, than you have to grind in the new valves! Everything else is shit (sorry, but it is, what it is). The old valves and the old valve seats are a matching pair. But it's not anymore a pair, if you only install the valves without grinding in.



-> TW200 manual page 4-24 and 4-25 <-





@ Danport

If you don't have much experience, than you should go to a repair shop.

You will need:

- valves

- valve seals

- head gasket

AND

- the rubber gasket from the oil line (for the camshaft)



Sebastian
 

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@ TWBARR

You've changed the valves but you haven't grinded then in?

At first: I am a bike mechanic.

And the second: If you want a perfect job, than you have to grind in the new valves! Everything else is shit (sorry, but it is, what it is). The old valves and the old valve seats are a matching pair. But it's not anymore a pair, if you only install the valves without grinding in.



-> TW200 manual page 4-24 and 4-25 <-





@ Danport

If you don't have much experience, than you should go to a repair shop.

You will need:

- valves

- valve seals

- head gasket

AND

- the rubber gasket from the oil line (for the camshaft)



Sebastian


I did a compression test and poured gas into the exhaust and intake and there were no leaks and compression came back within near perfect specs.
 

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Discussion Starter #12
Thanks for trying to help me.

I decided the engine work was beyond my abilities.

I took it to the shop today.

Can't wait to get back a Tdub with a like new engine.

Safe and fun riding to you all.
 
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