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CJBennett
CJBennett, Small Engine Technician
Category: Small Engine
Satisfied Customers: 625
Experience:  Briggs and Stratton Master Service Tech, Kohler, Tecumseh, Kawasaki certified. 18 years exp.
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lawnmower turns over until it gets to compression stroke.

Customer Question

lawnmower turns over until it gets to compression stroke. bypassed all safety switches, put current directly to starter motor, same results. Used jumper cables from car directly to starter motor, same results. Remove plug, motor turns fine. Had same trouble a few years ago, guy said the wiring harness was damaged when i bypassed harness. i thought then that the starter motor was bad, bought a new one but had same trouble. i can't find anything wrong with current wiring. fuse is good. scotts 1742, intek 17hp, purchased 1998, can get serial # XXXXX needed
Submitted: 7 years ago.
Category: Small Engine
Expert:  CJBennett replied 7 years ago.
Hello. The first thing I would do is adjust your valves. With the engine at top dead center they should be set at .004 . If adjusting the valves doesn't take care of the problem you could have a bad decompression on your camshaft. The decompression lets the exhaust valve hang open a little till the engine starts. If it is bad you will have to replace the camshaft.
Customer: replied 7 years ago.
can i adjust valves from the outside? i'd rather not take the head off. i took the valve cover off and observed the valve movement without the plug in place. valve movement and timing (as best as i can tell) are ok
Expert:  CJBennett replied 7 years ago.
Sure you can. Pull the plug and turn the engine over till the intake valve closes and the piston is at the top of its stroke. That's top dead center. Then check the clearance inbetween the rocker arm and the valve stem. You will need a .004 feeler guage. You can adjust them by turning in the nut that holds the rocker arm on the stud. Make sure it's a tight .004.
Customer: replied 7 years ago.
the valve clearance was little excessive, i tightened it up and set it as best i could with a .005 (smallest i have). put the plug back in, still stops on compression stroke.
Expert:  CJBennett replied 7 years ago.
You've got a bad camshaft then. The engine is going to have to come off and a new cam installed. I do them all the time on the Inteks (plastic camshaft).
Customer: replied 7 years ago.
please enlighten me. if the valve actuation is good, how can the camshaft be bad?
Expert:  CJBennett replied 7 years ago.
The decompression lever on your camshaft has a broken spring. The spring engages the lever and lets the exhaust valve hang open a little while starting it (relieving compression). Once the engine starts the centrifical force diengages the decompression.
Customer: replied 7 years ago.
do you know the b&s part #'s i need? if i replaced the whole assembly (camshaft, springs, bearings, etc...)?
Expert:  CJBennett replied 7 years ago.
Sure, whats you engine number?
Customer: replied 7 years ago.
b&s model 311777
type 0143-E1
code 981104ZE
Expert:  CJBennett replied 7 years ago.
The camshaft kit part number is XXXXX The gasket is 692226, and the lower seal is 291675S. It's not to bad of a job. Just make sure you line up the timing marks on the gears. Reset your valve clearance when your done.
Customer: replied 7 years ago.
does the camshaft kit include the spring and/or lever you mentioned?
Expert:  CJBennett replied 7 years ago.
Has everything you need to do the job.
Customer: replied 7 years ago.
Looking at the parts manual, I can't find the decompression lever or spring. Not trying to be a smartass, i just want to be on the same page
Expert:  CJBennett replied 7 years ago.
It is built right into the camshaft. You will not be able to see it on a diagram.
CJBennett and other Small Engine Specialists are ready to help you
Customer: replied 7 years ago.
thanks
Expert:  CJBennett replied 7 years ago.
No problem. Your welcome.