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Briggs OHV - Valve Adjust & Compression Release - Hard Start

dbkh
12 years ago

Briggs & Stratton 14.5 OHV - Valve Adjust & Compression Release - Hard Start

Received mower with the front 2 hold down bolts stripped and missing and the other 2 loose. Engine had been slamming itself back and forth so hard that it had shaken OFF one of the little swivel caps that sit on top of the valve stem (under the rocker arm).

Engine now runs good, but very stiff compression and very hard to get to turn over - - even when backed up against TDC and when jumping with a strong car battery directly to starter.

I've already adjusted valves several times and now (if doing it right) have set at 0.002 / 0.003 (Intake / Exhaust).

This turns over only slightly easier, but has so little vacuum that it takes several cycles to get fire.

Model # 287707 Type # 0224-01 Code # 960828ZD

Intake . . . . . . . . . . . . . 0.003 - 0.005 in. (0.08 - 0.13 mm)

Exhaust . . . . . . . . . . . 0.005 - 0.007 in. (0.13 - 0.18 mm)

Someone in another thread (that was closed) asked about valve adjustment

>> It's seems difficult to determine what is 1/4" beyond TDC.

Exactly. 1/4" beyond what? What is measured?

>> I also suspect the compression release is not working correctly but I don't how to check it.

I would love to know this too. To actually look at it, I think I would have to pull the whole engine and then pull the oil pan = a huge job.

Any help / thoughts / suggestions?

Thanks

Comments (16)

  • dbkh
    Original Author
    12 years ago

    Thought your email wasn't working.
    Ok, so I used the email link on your "My Page".

  • dbkh
    Original Author
    12 years ago

    Also, I have the "Illustrated Parts List" for
    Model Series 287700, Type Numbers 0026 through 1290
    For use on engines built before date code 02120200

    Mine again is
    Model # 287707 Type # 0224-01 Code # 960828ZD

    Anyway, have studied that pretty close and can't find anything in there that looks like or is labeled as a compression release arm.
    What part should I be looking for?
    And any clues on deciphering the date code?
    Do I have the right Illustrated Parts List?
    Thanks

    Note:
    Looks like there were 3 different cam shafts for this model series and date code. And which one depends on the date code.

  • tomplum
    12 years ago

    An fyi- 790400 (698492) is the cam for your engine. The arm is part of the cam.

  • walt2002
    12 years ago

    I have instructions which include how to determine if you compression release is working.

    Walt Conner
    wconner5 at frontier dot com

  • dbkh
    Original Author
    12 years ago

    >>I have instructions
    Ok, just sent you an email Walt.

    >>The arm is part of the cam.
    Don't see anything on the cams in the diagrams - oh well.

    Thanks all.

    I found the date code info.
    Those last 2 zeros (on the Illustrated Parts List) through me off and first google result said MMDDYY = WRONG.
    http://www.ehow.com/how_5616636_read-briggs-stratton-date-code.html
    The code is the manufacturing date and is read as follows:
    YYMMDD & ASSEMBLY LINE AND MANUFACTURING PLANT

    So the date is ok for the Illustrated Parts List.
    Don't know if the Model # is though.

    Here is a link that might be useful: Wrong Info

  • mownie
    12 years ago

    Paraphrased from Briggs.

    {{gwi:317492}}

  • dbkh
    Original Author
    12 years ago

    Yep, like I said.
    The wrong info is MMDDYY.
    The right info is YYMMDD & ASSEMBLY LINE AND MANUFACTURING PLANT.

    Also, would that part number 790400 (698492) be the latest greatest version or the original duplicate?
    If original, would it be better to opt for an improved version?

    Thanks

    Found a pic of similar cam with CR here:
    http://www.doityourself.com/forum/outdoor-gasoline-power-equipment-small-engines/334366-briggs-stratton-28n707-15hp.html

    Here is a link that might be useful: Pic of cam with CR at bottom of thread.

  • doogle45
    11 years ago

    will you please e mail these walt for the compression release check and adjusting valves

  • walt2002
    11 years ago

    Address put in proper format and include model number and what you want.

    Walt Conner
    wconner5 at frontier dot com

  • Rusty Bridges
    8 years ago

    I would like to know easiest way to find 1/4 past tdc

  • tomplum
    8 years ago

    When the intake (lower) valve is actuated and closes- follow the piston up to the top of its travel and continue 1/4" as it starts to go back away from the top. Use a dowel or something similar and turn the engine clockwise as viewed from the top.

  • Bobby Hadden
    2 years ago

    Remove valve cover,remove spark plug. Put a screwdriver in plug hole . Turn engine by hand watching screwdriver move and also the valves to determine which valve is open. To set tdc you want the intake valve to be open.For 1/4inch past TDC mark screwdriver and turn engine slow to 1/4 inch.

  • mownie
    2 years ago

    "To set tdc you want the intake valve to be open" You don't set the valves when they are "open". Valve lash or clearance can only be set when there is no contact between the valve stem and the rocker arm. If the valve is open that means the rocker arm is pushing the valve open.

  • tomplum
    2 years ago

    Good to see you Larry. How's things by you?

  • mownie
    2 years ago

    I'm doing well Tom and I hope you are too. Please send me an email. Thank you