Briggs 675 series not starting w/ video & pics

[emckissack]

I posted this at the Small Engine Tech Forum as well but figured it would be lost in a few months so here it goes.
Hi, New guy here.
I am having a problem with a Briggs and Stratton 675 series 6.75 Hp engine not running. I was using it and it ran out of gas and hasn't ran since. I have rebuilt the carb with a rebuild kit except for the freeze plug, pulled the head off and inspected the piston and valves. Not sure how I can tell if everything is timed correctly though. Replaced the spark plug and filter. I don't really want to buy another motor. This one should be just fine.

Let me add that when the engine ran out of gas and quit, I checked the oil and it was very low. I replaced the oil before trying to restart it.

When I pulled the head off there was oil in front of the piston, enough that when I turned the piston to TDC it pushed the oil over the edge an let several droops spill onto the pressure washer caddy.

Not sure if this helps or not.

Here is a video of what is happening .....http://youtu.be/uXx2HGpPYF8

I have checked the flywheel key and it looks to be in the right place
http://i66.photobucket.com/albums/h277/emckissack/7a1d58ed-c620-42b8-928f-32b37ddff921_zps21d01d82.jpg

And I have checked the Piston and Valves and this is what they look like.
http://i66.photobucket.com/albums/h277/emckissack/b4ac0e7d-34ba-4687-9f3c-bf2eb04dd174_zps31fa92c1.jpg
http://i66.photobucket.com/albums/h277/emckissack/c8110d47-292b-4988-a45a-731c02ff2359_zps7d6ef123.jpg


And here is a video of the cylinder and head timing. Does this look normal?
http://youtu.be/YxNOAMk-C-Q

I don't want to have to tear this thing anymore than I have to so any suggestions would help.
here is a link to a thread I started on another site http://www.ar15.com/forums/t_1_5/1561534_Need_help_with_small_engine_repair____.html

Thanks for your help

[bgsengine]

First: viewtopic.php?f=1&t=1 - Post engine numbers 675 series could be anything. Need model, spec and code.

Second: Can't really help when you just tear in to something without a step by step diagnostics.
You need to put the head back on and do a compression test and leak down test which would tell a lot more

You could have bad rings, scored cylinder, leaking valves or seats, maybe carburetor not assembled right, maybe forgot to put gas in it in the first place, maybe water in gas or plugged tank or shut off valve not opened. Maybe just a bad spark plug (New is not the same as Good) does it have spark? did a spark test? check for air leaks? Any number of things could be wrong with it. No one can really help until you're ready to post engine numbers and follow some step by step diagnostics - Other than that all anyone here can do is offer SWAG (Some WIld @$$ Guess)

[RoyM]

Is the cylinder wall galled or scored? That engine appears to have been overheated. See my post on the old forum.

[emckissack]

Thanks for the reply.....
Have you taken a look at the videos posted? You will see that it has spark(New Spark plug), because it tries to run, and gas (fresh gas) and that the carb is spitting the gas out the wrong way. My assumption was that the timing is off so I made another video of the piston and valves working. My question at this time is if the valves and piston are working the way they are supposed to in order to hopefully avoid tearing into the lower end. There is a link at bottom of my first post that will take you to a thread with easy access to the videos an pictures.

the model # of the engine is as follows: 126T02-0114-B1 07072758

I do not have a compression gauge but there seems to be a good amount of pressure building up when I attempt to start the engine as seen in the video.

Take a look at the second video in my 1st post and check out the timing of the valve and piston Thanks.

[emckissack]

Is the cylinder wall galled or scored? That engine appears to have been overheated. See my post on the old forum.

The cylinder wall is smooth and shiny except for a single score that can be felt with a fingernail. BTW this engine has less than 25 Hrs on it.

BTW you say to replace the washer? What is that? I hope you didn't mean the whole pressure WASHER.

[bgsengine]

I don't speak for the rest but I do not bother even viewing Youtube videos. Takes too much time - Many of us are working professionals taking a few minutes a day of our schedule to try and help. Quick, short text descriptions, Model and serial numbers of the equipment in question (so we can verify what exactly we are dealing with) and steps taken to try and diagnose the problem work best and get the best results.

Matter of fact, most Youtube videos do not run on the computer system I usually use from the office here, due to security limitations (It is after all, a business network here - Security settings bordering on Paranoid.) which is another reason I never even go to youtube.

Valve timing - Easy way to figure if it is in time or not (and it is extremely rare for an L-head to jump time without much more severe damage having happened) Watch the valve action as piston comes to TDC - Roll engine over TWICE by hand - as piston comes up on TDC Compression (the last 1-2 inches of stroke) both valves should be closed, one of them may open slightly and then close (that's compression release at work.) , and on the next revolution, Exhaust valve will be open as piston comes up, as piston gets to the top and crank turns over to start back down, Exhaust valve will be closing, *AND* Intake valve will be beginning to open. At TDC, both valves will be slightly open.

If that is the case, valve timing is where it should be.

[emckissack]

Again thanks for the reply....I am not a professional by no stretch of the imagination so videos and pics say soooo much more than I can explain on a forum. Maybe when you have time to view the video you can see exactly what I am looking at as well. The valve slightly opening for decompression was a concern of mine at first but apparently that is normal. This is my first engine teardown so parts and nomenclature are foreign to ma at this time. Thanks so far....Eric

[bgsengine]

BTW you say to replace the washer? What is that? I hope you didn't mean the whole pressure WASHER.

Correct - If the engine is so far gone that it would need to be rebuilt or replaced, it is often cheaper to simply replace the entire machine. New replacement engine might run you $250 - $300 , new power washer on sale at sears , maybe $285 and you get the warranty too.

Depends on the equipment it powers - If you have a common consumer Sears or Briggs/Generac/Troy-Bilt or TTI (Power Stroke, Homelite, Ryobi, Etc.) , then it'd often be cheaper to buy a new power washer than to try and rebuild or repair internal engine issues. If you have a high end Honda or Karcher, or similar where new units run $600 - $1K and up, then repower or rebuild may be a more cost effective option.

[KE4AVB]

With the amount of oil being left behind and the pattern tells that your is needing a rebuild. The rings are not sealing and are not cleaning the cylinder as they should.

Added fact that it was very low on oil is leading me in this direction. Just because it has just 25 hrs on it doesn't mean much when an engine is ran with low oil levels; it can't be lube properly if there is no oil. These engines uses a splash oil system. I had a engine in the Spring that only had 5 hrs on it and it was destroyed. The operator ran it without the correct air filter. It was a cheap push mower and replacement mower was less than the replacement engine and definitely less the cost of the rebuild.