12.5 won't start?

[Shady Brook]

I just replaced the sump seal on my 12.5 kaw. put her all back together on my scag 36, and now she won't start. It is blowing some stinky stuff, and smoke out the muffler on some of the pulls. I have pulled this thing about 200 times, and nothing. I think turning the engine over, may have caused a gas oil mixture. I had this happen on a Toro once. She would not start, and the engine acted siezed up. Same thing on the scag, so I pulled the motor a second time, checked things out, and put back on. On first instalation, I could not pull the chord, acted siezed. Second time, I could pull laboringly. Now after a couple hundred pulls, she pulls pretty normal, but still no start. Help me please.:confused: :)

Oh, also, I pulled the spark plug, and it had a oil residue on it, so I cleaned it up, and replaced, still nothing. Let her set a few hours, tried again, same story, no start.

Thanks in advance
Jay

[vipermanz]

sounds like the pulling problem could be a sheared flywheel key

[Robert Doubrava]

If the plug had oil on it, could it possibly be an internal problem?

[Richard Martin]

Hmm... I'm going to assume that while you had the base (sump cover) off of the engine that you did not mess with the camshaft.

You need to eliminate causes of starting problems in order to find out why it won't start.

I would start with making sure it has a good, clean supply of fuel. Change the fuel filter. Remove the float bowl from the carb and clean it out. While you have the float bowl off make sure the float isn't stuck. It should move up and down freely.

Next remove the spark plug and throw it away. Get a new plug and gap it properly. With the new plug make sure you are getting a good spark.

Now while the plug is out of the engine pull the engine over about 10 to 15 times. This should clear any oil or other nasty stuff that is in the induction system and combustion chamber. Put the new plug in the engine.

Change the oil and filter.

Disconnect the engine wiring from the mower. By doing this you are eliminating any wiring problems the mower may have developed while you were moving the engine around like pinched wires and/or disconnected safeties.

Put the choke on and give the engine a few pulls. It should start. If it does start kill the engine by turning on the choke again. Reconnect the wiring and try to start the engine again. If it won't start then you have a wiring problem.

If you have eliminated everything I mentioned above and it still won't start then come back and tell me and I'll tell you how to do a rudimentary camshaft timing check.

[Dave]

Richard i s correct I amsume this motor was turn up side down ,filling everything with oil even the carb,It sounds like its trying to ignite oil and thats what the smell and smoke is,pull the plug and do what Richard said,also you might want to spray some carb cleaner in to the cylinder and carbto dilute the oil,pull it ten times or so them put a new plug in it

[Shady Brook]

Thanks for all the suggestions men! Still no go.

Oil defineately got into the carb, and into the air filter and such. I pulled the carb off, hosed it with cleaner, and filled the carb up with sea foam to help clean it up. I sprayed carb cleaner in the cylinder, and just about anywhere that I could shoot it. :D New plug went in, pulled 250,000 times give or take 10. No start, sore shoulder, bad disposition. I used starting fluid, some extra noise, almost seemed like she wanted to kick over a couple times, but still not go. Help!

Jay

[Fish]

Did you have the sump off? If so, what else did you happen to
move, pull out, look at, etc..? What about the wiring to the
coil? Try pull starting it with the wire disconnected. Go through
everything you did from the start. If it ran fine before you
worked on it, then something is not right and the solution is
simple.
Fish

[Shady Brook]

The coil is fine, I did a spark test, and there is a spark. Even after cleaning the carb, after several pulls, I am seeing a oily residue in the carb again. Maybe I have not cleaned the carb throughly enough. I really did not touch anything else. I separated the motor to get to the sump gaskett, and replaced another seal. Really did not handle the internals of the motor. I gave some mighty pulls with some seafoam in the carb, and she acted like she wanted to start, but once that seafoam departs, she does not seem like she is inclined to turn over. I can get almost the same effect with the starting fluid, but it takes a big pull, and only lasts for a couple pulls before fading. I think it must have to do with the oil getting into the carb. Not sure how to cure it, unless I go get some varnish and soak it. Seems like it should start with just a little oil in there. She has been a hard starter for a while now, and I can not figure that out either. Float looks fine, but in any event, something is wrong.

Jay

[65hoss]

Check all your OPC switches. You may have one bad. Make sure the blade engagement linkage is not slightly engaged. The Trans is in neutral, if its slightly off it will not start.

Pull the dipstick and see if gas is in the crankcase.

[Shady Brook]

ok, I am about to loose my mind.

I have done everything I can think of to get this beast started, but no go.

I have changed carbs, and she still will not start. The carb is not the problem. I think I must have oil in the combustion chamber. Any thoughts on how to clean that thing out? I am really frustrated after fooling with this thing for several days. Wasted!

Thanks
Jay

[Richard Martin]

Did you do everything that I outlined above? The "combustion chamber" cleanout is included in my instructions.

[Shady Brook]

Richard

Yes, thank you for the great post. I did what you said over several times. I continued to get oil in the carb after it all. But I wonder if maybe the timing might be the issue, or part of it. Could you give me instructions to check the timing to elimate that as well? Thanks
Jay

[Richard Martin]

Bear in mind that checking cam timing this way is no guaranty that the cam timing is right. It will only tell you if it's grossly off.

One way is with a compression gauge. Put the gauge in the engine and give the engine a few pulls. If the compression is low (20 to 30) then you may have a problem with cam timing.

The second way is a little more work but a lot more reliable. Pull the head off and slowly rotate the engine clockwise until you see the exhaust valve open. The piston should be headed up in the cylinder. Keep rotating the engine until the piston reaches the top of it's cylinder. At this point both valves should be closed. Now continue rotating the engine. The intake valve should open as the piston heads down in the bore and then close as the piston reaches the bottom of the cylinder. For the next up and down cycle both valves should remain closed. Then the whole process starts over again.

[cnflawn]

hi
i know this sounds silly but ive been there already.
remove 2 nuts at head that hold muffler on. move muffler enough that gas oil mixture will run out. its there believe me. pull plug . pull engine over several times. install plug and restart. dont feel bad it is very aggrevating. you can test this problem by doing a leakdown test and youll notice no air coming out when the exaust vale is open.
jerald

[Shady Brook]

Jerald

I have had that muffler off cuz I thought the same thing. I did not have any oil come out of the muffler, and did not see any oil draining out of the engine from there either.

I am thinking more and more it is beyond the oil issue. I will look into the compression test, thanks Richard.

If it is timing, would it act like it wants to start better when using starting fluid and such?

Thanks
Jay

[cnflawn]

hi again,
sorry that didnt work, will you please do a compression and a leakdown test and let us know the results. the possibility is you bent a valve with oil in the cylinder. the 12.5 has push rods and no overhead valves so you can pull the head pretty quick to check operation of the valve train. unless youre 400 lbs of pure muscle i dont think youll shear that flywheel key by pulling the rope. the above thought is assuming everything went back in correctly. i hope you fix it quick because that 12.5 on a 36 scag is a great unit.
jerald

[Shady Brook]

Thanks cnflawn

I sure will let you know what I find out. Could you give any pointers on the process of pulling the head, and what to look for when inside? I did not get to try the timing out, but maybe this way I can kill two birds with one stone. My PSD won't start! Always something! I am in the process of charging the batteries, and I have the block heater in, so hopefully I can get her going tomarow.

Thanks again
Jay

[General Grounds]

:blob3: Shady B, when you put the engine back together did you use a feeler gauge in mounting the coil, you may be a little to far away and not getting proper or spark at all, you may also have a bad ignitor which is mounted on the outside of the engine and is about 1"x1" this could aslo be bad, if you have another kawi try borrowing from the good engine b/c an ignitor is an expensive part if were not sure. Tony

[Shady Brook]

Tony

I did not use a feeler gauge, nor do I even know what it is. :) Should I have used one? Can you give any more info on how I can check this? Where is the ignitor, can you describe it for me?

Thanks
Jay

PS. I did use a spark tester, and was getting spark, not sure if this is what you mean though.

[cnflawn]

hi jay,
man i hate to hear about the power stroke. i thought they would crank anytime. i had the old 7.3 they were a chore but my ps has never let me down. as to remove the head just take the sheetmetal off the front and top. take the head bolts out. make sure to remember where the bolts come from as some are different. slowly rotate engine CW using flywheel nut. watch valves open and close. the intake valve should open about about 1/4 inch followed by the exaust valve (bottem one). in between they both should be closed completely. good luck with the ford.
jerald

[awm]

i still tink it is just gummed up from letting oil run into everything.
change the plug. let it set upright a day or so and use starter fluid to crank it. hope something works, good luck now.

[Shady Brook]

You guys are just super!

I have the head pulled as I type. There is oil in the cylinder, and on the top of the piston. Pretty messy, I can see how that oil would hinder combustion. Any other observations I should make, actions I should take at this point. Any ideas would be appreciated.

As far as the timing goes:

Starting with both valves closed and piston up in cylinder.

Intake valve opens as piston comes down cylinder.

Intake closes as piston heads up into the cylinder.

Both valves are closed as piston comes down cylinder.

Exhaust valve opens as piston goes up the cylinder, BUT does not close til the piston begins to come down the cylinder again, and simultaneously upon the closeing of the exhaust valve, the intake valve begins to open again, as the piston comes down the cylinder.

The intake valve is open to it's fullest with the piston all the way down, and begins to close as it goes back up the cylinder again, and closes about half way up.

The rest of the way up the cylinder, and all the way back out the valves are both closed.

Does not seem to match with what Richard and cnflawn indicated it should. Help! :)

[Shady Brook]

Is it possible that my timing has been off for a while? Could the mower start with this senerio, but be a hard starter. Mine has been very hard, sometimes 50 pulls even when it is warm out. I just wonder if that is the case, or if I cobbed it up when I changed the seal? How do I correct this?

Thanks
Jay

[Richard Martin]

It definately sounds like the cam timing is way off. The engine might run with the cam timing like this but if you could get it to start it wouldn't have any power.

Your next step is to clean out any oil that you can and then head to the dealer and get a new head gasket.

There should be a mark (like a round punch mark) on the gears of both the crankshaft and the cam. If when you rotate the crankshaft these marks do not line up then you need to line them up. The cam will pull out of the block but you may to push on the lifters a little to get it out.

[Robert Doubrava]

That's the mitake we made when we overhauled a 7HP B&S vert. We did not set the timing very well!! It didn't run very well at all.
Well, good luck on your engine!!:)

[Shady Brook]

Thanks for the support fellas.

Seeing how I am going to have to take everything apart again, does anyone know the official torque pattern, and torque numbers I am to apply to these head bolts, and to the part pertaining to the sump area? Should I leave the head off when I go back to change the timing, or does it not matter to much at this point? I am thinking of redraining the oil, and pulling the muffler and carb. Boy this is really not as much fun as I had hoped for. :(

Thanks
Jay

[Robert Doubrava]

Well, I hope that it gets to be more fun for you. It wasn't fun for me when we overhauled that old Briggs. One thing you don't want to do is put that Lok-Tite grease on the head bolts!!;)

[Shady Brook]

Thanks to all of you who spent time helping me through this problem!:blob3:

Special thanks to Richard, and CNFlawn, who walked me through the timing process!

I set the timing, put everything back together, 3 pulls later, my mower was running! :D :D

After a million pulls on the rope, it turned out to be a timing problem. Boy is my sholder happy that she is fixed.

Thanks a ton!

Jay

[Robert Doubrava]

Your welcome. I'm glad to hear that you got it fixed.:) :) :blob3: :blob3:

[Richard Martin]

I'm glad it worked out for you.

[Bill Kapaun]

I was thinking the air cleaner was clogged with oil, but I see you have it running!