QuestionQUESTION: hey, i have came across this site on google, im trying to find the valve adjustment specs for the motor listed above, the tecumseh OHH50. i cant find these specs ANYWHERE online. i found a site that said adjust them to .004 for both, and i had blowback threw the carboretor then i set them to .010 and im STILL having blowback threw the carboretor, i know the valves are not bent because i have really good compression. (not sure on PSI just holding thumb over) and i know there not burnt or need to be reseated because the motor ran great until i had to reset the valves (stupid move) however the rockers were really loose when the motor ran great,(why i adjusted them) on the bottom of the carboretor there's '20', and the guy at the lawnmower shop told me the valve clearance specs are under the float and it says 20. that seems a little wide but thats about what they were at before. can you help? thanks, -joel.
ANSWER: Hello Joel:
Sorry for the Delay. This Question was Located in the Question Pool. Did you Set the Engine to TDC (Top Dead Center) when you Set the Valve Clearance? The OEm Does Suggest .004 for Both the Intake and Exhaust. The Following is the File I Send to Questioners that are Resetting the Valve Clearance on Tecumseh OHV Engines. I Do Not Use the Setting Called for by the OEMs. I have Found that the Following Works Best. Remove the Valve Cover (on the Dead Cylinder for Twin Cylinder Engines). Set the Cylinder you are Setting the Valves on to Top Dead Center (Both Rocker Arms will have Play in them when the Engine is at TDC) When Setting the Valve Clearance. Now Loosen the Valve Adjuster Locks and Set the Intake Valve Clearance to .004in -.006in and the Exhaust to .006in - .008in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: alright, i have set the motor to .006 BUT it was not on TDC. i set the valves to .010 @ top dead center (what i heard on another site) and i had a lil blow back threw the carboretor. but set the @ .020 and had no blow back threw the carb. which didnt really make no sence, but atleast i know the valves are sealing because it has great compression. so i should set it @ .006 for intake and .008 for exaust? at top dead center, and this wouldnt be on the compression stroke right?
ANSWER: Hello Again Joel:
TDC is when the Piston is at the Top of the Compression Stroke. The Engine Must be Set at TDC on Compression Stroke to Set the Valve Clearance. Set Both Valve Clearances with the Engine at TDC on the Compression Stroke. Thanks for Showing me the Oversight in the File for Setting the Valve Clearances I Use. I Should have Explained about the TDC of the Engine. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: alright, i set motor to top dead center and adjusted the valves i put the intake @ .006 and the exaust @ .008 and i am no longer back pressure threw the carboretor. but the motor will not start. any suggestions? im getting fuel on the spark plug and i have BRIGHT blue spark. and good compression. altho i have a flat spark plug, not a long one, should i change that out with a long one.
AnswerHi Joel:
If you have the Valve Clearance Set Correctly (and it sounds like you do), there is Gas going to the Cylinder and Compression, then Check the Flywheel Key. The Flywheel Key Sets the Timing for the Plug. If the Flywheel Key is Damaged, it will Cause the Plug to Fire at the Wrong Time During the Compression (Power) Stroke and the Engine Can Not Start and Run. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. Have a Happy Holiday Season and May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
