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Is it possible the crankcase breather pipe/hose is clogged?
 

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Discussion Starter #22
Hey Scooter

I pulled the breather hose off and checked it and the area where it connects to the air box, everything seemed fine. Also started the bike up with the breather hose disconnected, still burning large amounts of oil.
Is there a way to check if there is a back up on the metal tube that goes into the case? I just poked around, it did not appear to be clogged.
 

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I can't say about that, Balloonboy. Hopefully someone more familiar will chime in soon.
I wonder if a broken oil ring would cause some of the oil issue you are having. Just odd that something happened about the same time as our valve adjust.
 

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About all that engine noise. It seems when I read your thread that the noise did not start when the oil burning started but rather has been there all along... right?

If so, it means tear down and investigate. It'll be kinda fun if you screw your head on right about it.

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Discussion Starter #25
Ok, just got my 12mm spark plug adapter today for the compression test. It read at 98 with throttle closed, and 160 throttle wide open.

Fired up engine again today and let it warm up, it doesn’t smoke too bad until you give it some throttle, then it’s like someone lit a smoke bomb😄.

At this point I’m guessing I should pull the head off and start checking for damage and check valve seat seals? Anyone encountered anything similar or have any advice?

I work in construction in Atlanta, so holed up in my house at this point with some time to work on the bike. Hope you all are doing well.
 

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160 with the throttle wide open is fine, so you can eliminate the rings and valve seals (for the most part anyway)

So, with the engine idling it smokes “a bit”, and if you give some throttle, it smokes “a lot”

Logic would dictate (even though your engine has never heard of the term “logic”), that the oil is in the air/fuel mix

This suggests that either some kind soul at a filling station thought your bike was a pre-mix 2 stroke (which has actually happened before), or that your engine breather pipe is coughing up oil into the air filter

So, let’s start at the beginning ….

“It’s burning oil and smoking” – well, yes, but “160 throttle wide open” may be misleading

Time for an engine leak down test

 

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Is it possible one of the o-ring gaskets inside the head/cylinder has ruptured allowing oil into the piston area and the main base/head gaskets are keeping the oil from the outside?

For instance, the lower left passage way for the one of the head bolts. You won't know for sure unless you tear down the engine.
204336
 

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Just a guess but:

The timeliness and symptoms of the oil burning had me think valve guide seals from post #1. Still think Admiral likely nailed it a few posts ago. I would follow up on it initially with a good bright light inspection of the valve stem/ valve guide juncture. Possibly something inadvertently compromised one of the seals during valve adjustment.
During compression test the valve for the possibly affected seal is closed so having good compression is not likely that diagnostic of valve guide seal integrity. Would assume oil would get sucked past seal during intake stroke with higher loss rates & smoke noticed at higher RPMs as was observed.
 

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Blown head gasket will do it. I've seen it many times on lawn tractor engines. Along those lines....did you happen to loosen any head bolts by mistake when doing the valve lash adjustment? Just throwing darts in the dark.
 

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I'm not sure of this as I have not done this on the TW, can you pull the carb and see the intake valve stem as it passes through the intake port of the head. If the valve stem seal is leaking there should be oil in the intake port of the head and the valve stem.

with the smoke the exhaust side port will be wet no mater what.
 

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i have already changed the filter and forgot to drain the oil, and then added the correct amount. had twice the amount of oil in it.
 

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Forget to mention there was a strange sludge on the underside of the oil filter, consistency of mud. Can’t be a good sign.
If you have that sludge it may not have been lubricated properly for a bit. I flush the crankcase. I like to use diesel, fill the crankcase to proper level, then lean the bike back and forth pick it up shake it a bit and then drain it out. Put another load of diesel in it and run it for just a little bit. After this clean your oil filter and put fresh oil in it. Did you double check to make sure the 4 hole oil filter was installed?
 

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Discussion Starter #35
Hey everyone, thank you for all the advice, it has been very helpful.

I pulled the head off this morning, put some photos below. If you all want to chime in on the respective theories it would be greatly appreciated.
A419741C-B297-4715-A54A-798D804F92DD.jpeg


47DE79C6-F406-486B-BBBB-3EE080C06D61.jpeg

1st 2 photos are intake valve, large amounts of oil showing faulty valve seat?
C064867D-7F4B-4C8A-B2CD-CAFBBE4438B1.jpeg
9CDAC7C6-FD1E-4F2B-8C75-7D060CFA3A11.jpeg

Notice damaged seal at upper right dowel.

Obviously a ton of carbon build up on top of piston and head, what is the usual procedure for dealing with that?

There was a flakey silver compound on the head gasket, is it that way from the factory or has someone else been in here before?

Thanks in advance, hope everyone is doing well. In
 

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It looks like Admiral may have nailed it. That is the o ring he was talking about. There is a lot of oil flow through that so if it was leaking into the cylinder it would cause lots of smoke. By looking at the pictures the valve didn't look that oily. The flaky silver stuff sounds like someone may have tried to seal up the head gasket but I don't know with what. As far as getting the oily build up of carbon out I would try a plastic putty knife and scrape it first then a light wire brushing to finish it off. Then lower the piston some and wipe out the debris, lower a little more and wipe it off a couple of more times. That will get the loose debris out of the cylinder.
 

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Great pictures. See no evidence of oil getting past head gasket despite obvious rubber seal issue.
If you wanted to inspect the valve guide Viton seals you may wight have to pull valve keepers, springs, rocker arm etc to get a better look. They may be fine and unrelated to the stated oil burning but I would still check the whole valve train since so much disassembly has been done so far.
seals-l400.jpg
seals download.jpeg
seals hammer download.jpeg

Say, that pink hammer looks familiar! In front of the hammer is a valve lash adjusting tool from the lathe of Forum Member Gerry ( a.k.a. the original Mr.Gizmo).

Reason I mention valve guide seals again is that oil burning was reported to have only began just after the valves were adjusted . I don't usually believe in co-incidences so logic says look for what could cause a leak around the areas serviced.
However if oil burning pre-dated valve adjustment then disregard my concern and look elsewhere.
 

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Discussion Starter #38
Hey Ken,

that’s kinda what I was thinking. It looks like that is the pathway for oil to get to top of engine, correct? Bleeder is right above where that seal is. I’m going to order the seal and replace, fingers crossed!
 

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I forgot your mileage was so low. That may have been an assembly error from the factory. Hopefully they didn't put the oil scraper ring upside down if they had a newbie that day at the plant.
 
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