QuestionQUESTION: Hello John thanks for your patients, I check the throttle assembly,it is of good working condition,I have did a compression check 45/50 cold 45/50 with oil cold and 90lbs hot. I have put all new gaskets on 3 times, one new head gasket. Something is not allowing the motor to rev up? The motor was running ok when it went to a low idle, just being pulled behind a tractor. Any ideas would surrely be appreacateted. THANKS steve
ANSWER: Hello Steve:
The Compression is Really Low. Usually an Engine will Not Run with Less than 70psi Compression. Check the Valves for Proper Clearance and for Possible Valve Seat Burn. If the Gaskets are Good and the Throttle is Operating the Throttle Valve in the Carburetor, then Check the Muffler for Obstruction. If the Muffler is Not Exhausting Properly, then this Problem will Occur. I have Studied the Breakdown/IPL and Discussed this with my Shop Mechanics and Other than the Carburetor, Valve Clearance or Bad Valve and Exhaust, there is No Reason for the Engine Not to Run Properly. Can you Open the Throttle by Hand and Spray some Starter Fluid Into the Carburetor Throat while the Engine is Idling. When you Do this Does the Engine Rev Up? Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Hi JOHN
I put a new OEM exhaust on. I pulled head and the valves are not burnt, and seem to be operating. This morning I started it pulled air cleaner off and sprayed some starter fluid in carb after it went to idle, 1st time i sprayed it into carb it died, 2nd time I sprayed lesser amount off it into carb it cough started to rev but went back to idle, I tried 2 more times with same results? I though that 45/50 psi was ok because of easy start, 90 psi after it warmed up , i thought aluminum expanded??It seems to start really easy? I really have no more ideas except to buy a new one. If you have a new idea please share. THANKS Steve
Answer Hello Again Steve:
The Easy Start uses a Compression Release on the Cam and Opens the Intake a Small Amount Just Before TDC. If the Valve Clearance os Off the Engine will Not Increase in Speed. The Valves Open too Soon or Open To Early or Close to Late as the RPM's Increase. Check the Valve Clearance. The Gap Between the Tappet and the Valve Stem Should be >003in - .--5in Intake and >008in - .010in Exhaust when the Engine is on TDC(Top Dead Center). If the Valve Adjustment is Off the Engine will React the Way you Described. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
