Weird "Pffffffft.......pffffftttt sound
- Thread starter jspbtown
- Start date
So I just went out and took the motor off the bike. Checked the valve clearance. There was .006 on the intake but essentially none on the exhaust. Ground the valve stem and got a tight .012 on the exhaust. Checked everything again and bench started it. Still sputters and coughs and shoots pressure out the carb. I think there is something amiss on the internals. I have a lead on a couple of motors so we will probably go that route for now and I will keep it as a project motor since it looked real clean.
Business card is incorrect thickness, .0125 is the correct setting. Valve clearance of .012 is like throwing a hot dog down a hallway on a late model and 3x what it should be. I hope you were checking it @ true TDC If you were BTDC even by a little you may have been sitting on the tail end of the compression release bump which raises the exhaust valve on the HS engines.
Well I used this as a reference for the valve spec:
https://outdoorpowerinfo.com/engine_specs/tecumseh_valve_gaps.asp
And I tried to slide in a .006 feeler gauge through out the entire stroke and was never able to get a .006 gauge in there at any time during the stroke.
The standard business card is 0.014 inches thick which is pretty close......
https://outdoorpowerinfo.com/engine_specs/tecumseh_valve_gaps.asp
And I tried to slide in a .006 feeler gauge through out the entire stroke and was never able to get a .006 gauge in there at any time during the stroke.
The standard business card is 0.014 inches thick which is pretty close......
Sooooo.....ummmm...a very tight .012 is 3x .008?
Interesting....
Interesting....
What you SHOULD be looking for is the nearest Harbor Freight, get yourself a couple of clones, Because its apparent these super simple, outdated engines are a bit too complicated for ya! I could not find a coupon for the predaturd engine online but I did find some other goodies you can pickup while there, the top right one is all you. Best of luck. you need all of it you can get
Markus....you might go back and read what you said......
"Valve clearance of .012 is like throwing a hot dog down a hallway on a late model and 3x what it should be. "
And
"Specs are .004-.008 "
So......I suggested the exhaust exhaust clearance might be .012 (arguably its .008) but .012 is clearly not 3 times .008. Try typing .008 then the "x" symbol and then the number 3 and then "=" into your phone and tell me if the number you get is more or less than .012 OK?
And if you can't multiply .008 x 3 then ask your grandkid to do it for ya....
"Valve clearance of .012 is like throwing a hot dog down a hallway on a late model and 3x what it should be. "
And
"Specs are .004-.008 "
So......I suggested the exhaust exhaust clearance might be .012 (arguably its .008) but .012 is clearly not 3 times .008. Try typing .008 then the "x" symbol and then the number 3 and then "=" into your phone and tell me if the number you get is more or less than .012 OK?
And if you can't multiply .008 x 3 then ask your grandkid to do it for ya....
Markus....you might go back and read what you said......
"Valve clearance of .012 is like throwing a hot dog down a hallway on a late model and 3x what it should be. "
And
"Specs are .004-.008 "
So......I suggested the exhaust exhaust clearance might be .012 (arguably its .008) but .012 is clearly not 3 times .008. Try typing .008 then the "x" symbol and then the number 3 and then "=" into your phone and tell me if the number you get is more or less than .012 OK?
And if you can't multiply .008 x 3 then ask your grandkid to do it for ya....
"Valve clearance of .012 is like throwing a hot dog down a hallway on a late model and 3x what it should be. "
And
"Specs are .004-.008 "
So......I suggested the exhaust exhaust clearance might be .012 (arguably its .008) but .012 is clearly not 3 times .008. Try typing .008 then the "x" symbol and then the number 3 and then "=" into your phone and tell me if the number you get is more or less than .012 OK?
And if you can't multiply .008 x 3 then ask your grandkid to do it for ya....
You ''still'' need to check your valve clearances @ ''true'' TDC ,, with '' both'' valves ''completely'' closed,,, like I & the others stated before.
Spec. gaps are definitely .004 - .008,, & ''please'' use actual feeler ''gauges''.
I used to set them @ the middle of those specs @ .006, as I stated before also.
A crude way is,, you can stick the eraser end of a pencil in the plug hole,, ''with the piston up'',, & mark the side of the pencil with a marker next to the top base of the plug hole,, ''for reference'',, with keeping the pencil in the hole to watch in making sure the piston is all the way up,, while slightly &''slowly'' rotating the crank back & forth a ''wee'' bit,, & also at the same time watching for ''any'' valve train movement.
Around there is where you want to check your gaps .
Let us know what the gaps are.
I
Spec. gaps are definitely .004 - .008,, & ''please'' use actual feeler ''gauges''.
I used to set them @ the middle of those specs @ .006, as I stated before also.
A crude way is,, you can stick the eraser end of a pencil in the plug hole,, ''with the piston up'',, & mark the side of the pencil with a marker next to the top base of the plug hole,, ''for reference'',, with keeping the pencil in the hole to watch in making sure the piston is all the way up,, while slightly &''slowly'' rotating the crank back & forth a ''wee'' bit,, & also at the same time watching for ''any'' valve train movement.
Around there is where you want to check your gaps .
Let us know what the gaps are.
I
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