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Followup To
Question -
Eric,
I will adjust the valves this weekend. I can tell you that they are now (ballpark) a dime's thickness or better (.050). Here are the motor numbers in case we need them if this doesn't work. Have a great weekend.
Thanks,
Paul
Model - 287707
type - 1224-E1 ( E as in Echo)
Code - 000331ZE (Z as in Zulu - E as in Echo)
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Eric,
You are really going above and beyond for me. I appreciate it. I do not have a DC shunt or a growler, but if it comes down to it, I will have it done. By valve gap, do you mean the gap between the rocker arm and the valve stem? I did not check it, but I can tell you they are slapping pretty good. Seemed awful loose to me. I have never heard of the compression release mechanism. I will try to study it. In the mean time, I will get the information you need tonight.
Thanks,
Paul
Followup To
Question -
-Eric,
Good points. The push rods rolled good on the pool table (after cleaning of course) I was going to check the key, but the motor does the same thing with the spark plug in, and the spark plug wire off, so I didn't think it was a timing problem, like pre-ignition BTDC. The only thing I can think of is perhaps a weak starter motor. Any thoughts on that? I've had it off, cleaned it, checked the brushes, commutator, and windings (as best I could) to no avail. This is a real stumper for me and I'm miffed.
Oh, I forgot to mention, after mowing for a couple hours, when I turn the mower off, it will backfire one time after the engine stops. Sounds like a .44 magnum. Hope this helps.
Thanks,
Paul
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Followup To
Question -
Eric,
I have a rider with a B&S engine, I think 14.5HP,
OHV, 3 years old. I have 2 lawn mower batteries hooked up in paralell, and can jump it with my car, and still when it tries to turn over, when it gets to the compression part of the cycle it won't turn any further when starting. I have removed all belts, cleaned the flywheel, etc. When it does start, it runs fine. It turns over fine with the spark plug out. I have removed the head, and there was very little carbon buildup on the piston or head. I can turn it past the compression point by hand, and occasionally it will start if I don't choke it until it's turned a few revolutions. I have jumped directly to the starter to eliminate cable problems and solenoid problems. I'm at a loss. Any help is appreciated.
Thanks,
Paul
Answer -
Great trouble-shooting. Have you checked the flywheel key? Usually tractor engines do not shear keys, but I always check.
Secondly, did you check the push rods? I have found several bent push rods. A cheap, accurate method to check the push rods is to roll them on a piece of glass.
Let me know.
Eric
Answer -
A lot of engines backfire these days. EPA standards have required the engine manufacutures to produce clean burning engines, so they lean the fuel mix. The solenoid on the bottom of the carb is supposed to shut-off the fuel when the key is turned off to prevent back-fireing but many engines still backfire.
As for a weak starter, I've never found one but it can happen. I have found bad cables, but since you've bypassed them I doubt that's your problem.
Do you have a DC shunt? You need the shunt to check starter current draw because most meter can't handle the current the starter draws. This is the only way I know to check for a weak starter.
What did you set the valve gap at? Send the model, type and code number and I'll look up the compression release mechanism; some use a spring mechanical lever on the cam but most compression releases are ground on the cam lobes.
Let me know about the shunt and valve gap.
Eric
Answer -
WOW!! I've heard and read about growlers, but never actually saw one.
Anyhow, too much valve clearance can cause too much compression.
Set the vavles at .004 with the piston at top dead center.
Let me know if this helps.
Eric
AnswerA couple of thousands off can make a huge difference in compression. In the old days, the L-head cylinders, we'd grind a thousandsth or more off the intake to increase compression...but grinding too much prevented you from pulling the string.
Let me know what happens.
Eric
