210-5 10hp Briggs low compression / delayed start

[Whitfield 14]

Working with a 210-5 Wheel Horse powered by a 10 HP Briggs  / Model 1015 or 1020

(fan shroud #'s are MODEL 256707  /  TYPE 0119 01 / CODE 90020131.  

 

Dry / Cold = 30 lbs compression.  

Run 30 seconds and I cut it off and compression = 50 lbs.

No knock / No Smoke / reasonable good power.  No oil consumption.

 

Leak down had the faintest hiss at the top of the carb.  I pulled the head and checked the valves ~ suspecting intake may be tight.

Intake measured .005            As I understand specs are .006

Exhaust measured .007         As I understand specs are .010

 

Looks like exhaust vale lash is slightly tight but this does not explain low compression / slow start. 

 

 

 

 

Valve do not appear to be sticking in the guides and follow the push rods with good spring tension but I have not yet removed springs and keepers.

 

Cylinder bore is clean with no visible ridge and no scratches or gouges.

 

Just under 400 hours.  360-ish 370-ish 

 

Plugged my compression tester into my air compressor line to verify accuracy and compressor read 140 / my compression tester read 130.  At sub sub 75 psi I'd expect more than just a temperamental No start. 

 

 

 

Anything else I'm missing ~ where should I look next  ???

Edited December 20, 2015 by Whitfield

[gwest_ca-(File Mod) 11,393]

These engines have an automatic compression release so a compression test is not valid. One of the valves gets bumped near the top of the compression stroke to relieve some of the compression for easier starting. If the valve lash is too wide that bump does not take place and usually stalls the starter.

 

Garry

[Whitfield 14]

Thanks Garry ~ That would explain alot.  Is there another way to verify engine health?  

 

Maybe I'm barking up the wrong tree...   It was acting much like my old 4-stroke XR 250 when the exhaust valve had tightened up.

 

Is there a way to verify correct compression release function?  

 

Is there a preferred vendor for consumables >>> Gaskets belts blades and such?

[Howie 899]

Briggs actually tightened up those valve clearances up just a little, intake is .004 to .006 and exhaust is .007 to .009. Should be checked when piston is 

1/4 down in cylinder past top dead center. I think the compression release is on the exhaust. If one could ratate the engine backwards I think the 

compression would be higher. It is hard to get a true reading on one of these though.

 

David

[BESTDOGEVER 218]

With those hours and all the other specifics as stated I  would  clean up the head  get an easy start plug in it  then check the spark and carburetor  adjustments simply because  it  looks  a little  carboned up for  tthat  amount of  hours. It  could  be  a  ignition module  going  bad  that  is quite common on the briggs of that era.

[Whitfield 14]

Thanks ~ Yes with the new information I have I do believe it was running rich. 

 

A local shop did a check up mid season and CONDEMNED the mower (recommending that she not put any more $$$ into it).  It was at this time that carb adjustments were made.  With the new adjustments she was having troubles flooding trying to start.  When I checked it out last week Full choke was way too rich and mid throttle was not quite enough.  The start window was so narrow it was hard to find the sweet spot.  I believe I can dial this in with fresh carb parts and adjustments.  (I am lawn / garden small engine illiterate but Motorcycle / Marine / Automotive experienced).  I feel like I can tell what it needs ~ just a matter of figuring out the linkage, circuits, and adjustments, to make it happen.    

 

BIG THANKS!  ~ Easy start plug and Ignition module were not on my radar.  I will search for more info on module test.  I have the adjustable spark tester (basic coil power test).  

 

New gaskets and carb kit arrived but the elves who packaged the head-gasket threw it into a padded bubble envelope where it got bent, folded, and creased in shipping.  Ugggh!!!!