Damaged Spark plug - Page 2

Cravin01 · 07-22-2018, 10:19 AM

Good luck with it and glad to see Don getting after it. Hopefully you get the parts in quick, Aluminum melts at 1220' F, is there any concern of other damage than the topend, possibly aluminum chunks un the case?

tomrom · 07-22-2018, 10:45 AM

Quote:

Originally Posted by Cravin01

Good luck with it and glad to see Don getting after it. Hopefully you get the parts in quick, Aluminum melts at 1220' F, is there any concern of other damage than the topend, possibly aluminum chunks un the case?

Bad Rectifier? I have no idea what caused this.

Cravin01 · 07-22-2018, 10:53 AM

I have no experience with a meltdown like this either, hopefully it can just get a afew new part and be ok.

Sochin · 07-22-2018, 11:54 AM

I'd say a valve dropped and caused total meltdown, hope you get it covered under warranty indeed. That would require just get a new complete engine. Too much debris cycled around the oil vanes by now.

ben2go · 07-22-2018, 01:01 PM

Yep, dropped exhaust valve as I suspected. If the engine was running lean, the exhaust valve could have overheated and popped. If not, it was a bad valve to begin with.

blanc12 · 07-23-2018, 09:26 AM

Looks like it got hot. really hot. Is your carb stock?
running too lean can do this.

You may want to fatten it up.

zippy · 07-23-2018, 09:46 AM

On old VW automobile air-cooled engines a dropped exhaust valve was a frequent problem. If an exhaust valve was adjusted too tight, then when the engine got hot and the metal expanded, the gap between the end of the valve and the rocker arm would disappear entirely. Then when it got even hotter the valve would not be able to fully close; the hot valve would not even contact the cylinder head. Since the metal of the valve did not contact the metal of the head (did not seat with it) it could not dissipate its heat to the head. While this was happening more hot exhaust gases would rush around the now slightly always open valve and get it hotter still, until it would get so hot it would eventually break off and fall into the cylinder causing destruction. Maybe that was the cause here.

tomrom · 07-23-2018, 10:50 AM

Quote:

Originally Posted by blanc12

Looks like it got hot. really hot. Is your carb stock?
You may want to fatten it up.

Yes, Stock.

tomrom · 07-23-2018, 10:52 AM

Quote:

Originally Posted by zippy

On old VW automobile air-cooled engines a dropped exhaust valve was a frequent problem. If an exhaust valve was adjusted too tight, then when the engine got hot and the metal expanded, the gap between the end of the valve and the rocker arm would disappear entirely. Then when it got even hotter the valve would not be able to fully close; the hot valve would not even contact the cylinder head. Since the metal of the valve did not contact the metal of the head (did not seat with it) it could not dissipate its heat to the head. While this was happening more hot exhaust gases would rush around the now slightly always open valve and get it hotter still, until it would get so hot it would eventually break off and fall into the cylinder causing destruction. Maybe that was the cause here.

Could be, however there was the recommended gap.

blanc12 · 07-23-2018, 12:45 PM

Quote:

Originally Posted by tomrom

Yes, Stock.

Could have been too lean. The intake was still there because the air/fuel coming from the carb cooled it. The exhaust valve over heated along with the piston.

The new or repaired engine could do the same thing without adjusting the jets in my opinion.

Gh426 · 07-23-2018, 02:33 PM

Could be the timing was too advanced also, that will burn/melt thru a piston also.

Cravin01 · 07-23-2018, 05:37 PM

The stock carb on the Bashan Storm has a 105 main jet in it so I'd be surprised if the carb was too lean.

blanc12 · 07-23-2018, 07:34 PM

Quote:

Originally Posted by Cravin01

The stock carb on the Bashan Storm has a 105 main jet in it so I'd be surprised if the carb was too lean.

The damage to the piston is more than just a dropped valve. It got really hot. Lean mixture is the most likely reason.

ChrisWNY · 07-23-2018, 07:54 PM

Quote:

Originally Posted by blanc12

The damage to the piston is more than just a dropped valve. It got really hot. Lean mixture is the most likely reason.

If it was so lean that the engine melted down, wouldn't the engine have stalled or bogged down with the choke off? Usually super-lean engines won't run unless they're choked (or they bog badly when the choke is off).

ben2go · 07-23-2018, 08:46 PM

Quote:

Originally Posted by Gh426

Could be the timing was too advanced also, that will burn/melt thru a piston also.

Normally I would agree but timing is locked in on most motorcycle engines.

07-22-2018, 10:19 AM	#16
Cravin01 Join Date: Jan 2018 Location: Forney Texas Posts: 498	Good luck with it and glad to see Don getting after it. Hopefully you get the parts in quick, Aluminum melts at 1220' F, is there any concern of other damage than the topend, possibly aluminum chunks un the case? __________________ Visit me on YouTube at "Project Next"! https://www.youtube.com/channel/UC6KTCi2GVbfRDv-2XCqHhsg?view_as=subscriber 2017 Bashan Storm Keihen PZ30 Pumper Carb,115 main jet,35 pilot jet, gutted factory exhaust, Sambo Digital Speedometer,LED blinkers, H4 headlight,D.I.D X-ring chain 428,17/42 sprockets,UNI cone filter.
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07-22-2018, 10:53 AM	#18
Cravin01 Join Date: Jan 2018 Location: Forney Texas Posts: 498	I have no experience with a meltdown like this either, hopefully it can just get a afew new part and be ok. __________________ Visit me on YouTube at "Project Next"! https://www.youtube.com/channel/UC6KTCi2GVbfRDv-2XCqHhsg?view_as=subscriber 2017 Bashan Storm Keihen PZ30 Pumper Carb,115 main jet,35 pilot jet, gutted factory exhaust, Sambo Digital Speedometer,LED blinkers, H4 headlight,D.I.D X-ring chain 428,17/42 sprockets,UNI cone filter.
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07-22-2018, 11:54 AM	#19
Sochin Join Date: Jul 2017 Location: Montucky Posts: 209	I'd say a valve dropped and caused total meltdown, hope you get it covered under warranty indeed. That would require just get a new complete engine. Too much debris cycled around the oil vanes by now. __________________ 1991 Kawasaki KLR250
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07-23-2018, 09:26 AM	#21
blanc12 Join Date: Mar 2018 Location: Northern Maine Posts: 55	Looks like it got hot. really hot. Is your carb stock? running too lean can do this. You may want to fatten it up. Last edited by blanc12; 07-23-2018 at 12:43 PM.
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07-23-2018, 05:37 PM	#27
Cravin01 Join Date: Jan 2018 Location: Forney Texas Posts: 498	The stock carb on the Bashan Storm has a 105 main jet in it so I'd be surprised if the carb was too lean. __________________ Visit me on YouTube at "Project Next"! https://www.youtube.com/channel/UC6KTCi2GVbfRDv-2XCqHhsg?view_as=subscriber 2017 Bashan Storm Keihen PZ30 Pumper Carb,115 main jet,35 pilot jet, gutted factory exhaust, Sambo Digital Speedometer,LED blinkers, H4 headlight,D.I.D X-ring chain 428,17/42 sprockets,UNI cone filter.
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07-22-2018, 01:01 PM	#20
ben2go Join Date: Jun 2011 Posts: 1,335	Yep, dropped exhaust valve as I suspected. If the engine was running lean, the exhaust valve could have overheated and popped. If not, it was a bad valve to begin with.
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07-23-2018, 09:46 AM	#22
zippy Join Date: Jun 2016 Posts: 11	On old VW automobile air-cooled engines a dropped exhaust valve was a frequent problem. If an exhaust valve was adjusted too tight, then when the engine got hot and the metal expanded, the gap between the end of the valve and the rocker arm would disappear entirely. Then when it got even hotter the valve would not be able to fully close; the hot valve would not even contact the cylinder head. Since the metal of the valve did not contact the metal of the head (did not seat with it) it could not dissipate its heat to the head. While this was happening more hot exhaust gases would rush around the now slightly always open valve and get it hotter still, until it would get so hot it would eventually break off and fall into the cylinder causing destruction. Maybe that was the cause here.
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07-23-2018, 02:33 PM	#26
Gh426 Join Date: Feb 2018 Location: LA Posts: 74	Could be the timing was too advanced also, that will burn/melt thru a piston also.
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