Blue/Grey Exhaust at Start Up By mxmatt (Read 1,954 times)

[Deleted]

have you tried motor honey? lol just kidding.

does this only happen right after startup or all the time does it smoke?

[mxmatt]

The smoke eventually goes away.

[racerx125]

To me it sounds like bad piston rings as he is saying when the engine is cold and tries to start its starts shooting smoke but as the engine is getting hotter the rings expand and eventually the smoke stops. so it does sound like bad rings.
Cold engine= contracted rings
hot engine= expanded rings
That's what I think

[mxmatt]

May 23, 2014 13:13:49 GMT -6 racerx125 said:

To me it sounds like bad piston rings as he is saying when the engine is cold and tries to start its starts shooting smoke but as the engine is getting hotter the rings expand and eventually the smoke stops. so it does sound like bad rings.
Cold engine= contracted rings
hot engine= expanded rings
That's what I think

That is what I was thinking. Would they be making a ticking sound?

[racerx125]

I dont think the rings make a ticking noise O.o My engine makes valve ticking noise that gets louder when engine is getting hotter and accelerating but apparently my valves are set ok and they are normal

[Deleted]

what about valve guides? ive seen engines that act like yours with valve guide damage.or wear

[racerx125]

well my valves are pushrod not sure about mxmatt maybe his valves are not set right?

[Deleted]

these engines are overhead cam so no pushrods. im still thinking its valve guides.

[Alleyoop]

+10 on valve guides like I said after shutting off the oil is leaking through and then when you start it it goes away CLASSIC SYMPTOM of Leaking Valve guides.
Alleyoop

[kz1000st]

If it's anything it would be the valve guide seals. They might have toasted when you ran it dry.

[mxmatt]

May 24, 2014 18:48:06 GMT -6 Alleyoop said:

+10 on valve guides like I said after shutting off the oil is leaking through and then when you start it it goes away CLASSIC SYMPTOM of Leaking Valve guides.
Alleyoop

In the few months that I have been here I have learnt a couple things.  One of them is Alleyoop is almost never wrong.  The more I listen and diagnose, the more I am believing it is the valve guides as you have indicated Oh Great Alleyoop!  I agree with you KZ that when that oil pump chain gave way and I rode it for a few miles I likely burned up those seals.  Ugh!  I'll be ordering some new ones today.  Are they difficult to replace.  I have read some places that you have to heat up the head to 250 degrees before pulling them and others say you just pull them out.  Anyone replaced them in the 150's recently?  Also, will I cause any damage to the engine if I continue riding it until the parts arrive?

[Alleyoop]

Here you go mxmatt,
Found this video hope it helps:
Alleyoop

[mxmatt]

Hey Alley, I've been doing my homework on replacing these valve guides before I order them and I have a question for you. Ok, maybe a couple.

1. Is replacing these something I can do properly, or should it be left for a pro?
2. Is it necessary to use a Valve Guide Reamer or do new guides typically come "pre-reamed?"
3. What does reaming do?

Thanks.

[Bashan]

Unless you want to do it for the experience, how about a complete head, valves installed, just bolt it on.? Do you have a valve spring compression tool? If not you'll have to buy or rent one. There's more expense right there. I found this one on Parts for Scooters for $60.00. Me? I'd go with the bolt on.

[jct842]

But then again is it really hurting anything? The amount of oil burning off can't amount to a significant cost. As long as it is run long enough to burn the excess of the plug you should be ok. There isn't going to be any big power loss as it does not effect compression. Only down side is "it smokes" as I see it.