hard jerky cord pull

All of sudden the cord on my 4-stroke pressure washer Briggs Stratton engine is really hard and jerky-like when I pull to try to start it, it pulls a little way then stops, then I can pull it a little more, but can't pull a full pull to start the engine. When I take out the plug it pulls freely. Somebody told me the valve(s) may need adjusting. I took off the valve cover, (its an overhead valve engine). Here's a picture of it http://i207.photobucket.com/albums/b...1/IMG_1425.jpg
Any suggestions on what there I might try to adjust in or out, tighter or looser? The engine had been working just fine previously, no problem starting, then all of a sudden after sitting a few weeks I have this problem. Any comments/suggestions appreciated. Thanks

 

Does your PW have a pressure regulator? If so, make sure it is set to the lowest pressure setting.
Could be a pull starter/rewind problem, pump causing it or....
It doesn't sound to me like anything a valve adjustment will solve. Although you can verify that at least the valves are working with the valve cover off, remove the plug and spin the engine by hand and watch that both valves do travel.

Post the model #'s of the PW and the engine, and we can keep diggin'

 

With the valve cover off I verified that the valves are traveling as I spin the engine by hand. Yes, the PW has a regulator, which was at its highest setting. I turned it to its lowest setting and tried to pull the cord again, with the same result as before. Somebody else told me it "might be a hydraulic lock problem".
It's a Briggs and Stratton brand pressure washer model 020325, and it has a Briggs and Stratton engine Model number 050212.

 

Sounds a lot like a sheared flywheel key. Don't see that often on pressure washers though.

 

I was thinking the same as cheese except not much to shear a key on a PW. With quality control what it is tho, sure would be worth checking.

 

One person said "The increased starting effort is likely pressure building in the pump as you are propping it. If the gun is closed as it should be, the unloader is likely stuck".

I'm leaning toward that as the possible problem. So, if the unloader is indeed stuck, how do I fix that?

 

If that was the case, there would still be good resistance with the spark plug out. The plug has no relation to the unloader. Otherwise, I would agree.

 

I think I would leave the plug in it and pull off the plug wire, see if it still locks. If it does, pull the plug and spin the engine over about twenty times. That may have some liquid in the cylinder = hydro lock.

 

Good suggestion, I agree. That will tell you if it's the flywheel key or not.

 

In the case of liquid in the cylinder, how did it probably get in there, and how do I get it out? Will the spinning the engine over about twenty times with the plug out help to remove the liquid? It seems kind of strange to me because I had been using the PW just three weeks ago, starting it and stopping it plenty of times while doing some cleaning projects, and it was fine then. Then, today I brought the PW out to use it and have this issue all of a sudden.

 

There is some resistance with the spark plug out, but hardly any.

 

Yep, that would take care of it. The pivotal thing on this is when you have the plug out you have a free spinning engine.

Also, check the oil level in it and make sure it isn't over full. You may have a fuel leak that's filling the cylinder/crankcase.

 

I checked the oil level and it's just right. With the plug out I have a free spinning engine. I've pulled through with the plug out many many times but there's never been any sign of any liquid to emerge from the spark plug hole. With the plug in, when I pull on the cord it pulls about halfway until there is an excessively strong resistance from the engine/pistons at about that point which prevents a full smooth pull. Continuing to pull hard on the cord past that halfway point where the strong resistance is felt, the cord seems to pull okay the rest of the way. Just can't get a full pull because of what I just described. Like it's semi "locked up" at the halfway point in the pull, and, ONLY with the plug in. Any more thoughts/comments/advice?

 

Have you tried to start it @ the same time as you hold the handle of the nozzle in??? Have you checked the flywheel key yet?? If the nut on the flywheel isn't tightened properly, the key will shear... If you haven't any liquid in the cylinder,, that's about all I can think of... Roger

 

Yeah I tried to start it at the same time I hold the handle of the nozzle in. Made no difference. No I haven't checked the flywheel key yet because for one thing that would probably entail some considerable disassembly to inspect, and I'm not a small engine mechanic and don't have anything like a service manual for the engine. The last time the pressure washer was used was just a few weeks ago, pull starting fine over and over then with no such problem as is happening now. Then, grabbed the washer to use again and all of a sudden have this problulem. Seems like the flywheel nut wouldn't just loosen on its own just sitting there, same with the key, it wouldn't just all of a sudden be sheared when it was fine the time before, would it? I actually took it to a small engine fix-it shop today and demonstrated the problem to the guy, and he couldn't figure it out either.

 

So I called a Briggs & Stratton authorized repair center described the issue with the mechanic there. He said if it's not hydrolock, or overfilled crankcase, that he might check the valve clearance. Otherwise he too seems rather uncertain (without actually looking at the engine) what could be the problem. Any comments about that advice? Could valve clearance not correct cause the problem as I've described?

 

I don't see where you replied about trying to spin/pull the engine over with the spark plug installed, but leaving the spark plug wire off...???

If you have and or posted, maybe you can verify the results...? If with the plug wire off, it still locks, then that might well show the flywheel key is not the issue as a couple of others here have alluded to.

If both valves are traveling nearly the same distance, I don't think the valve adjustments are off so far to cause this issue, performance while running maybe, but should not do this as far as I know. Maybe if one of the pushrods had fallen out or such....

 

I tried spinning/pulling the engine over with the spark plug installed, but leaving the spark plug wire off. Result: Makes no difference.

 

It really shouldn't be a valve issue, unless that engine has a compression release for starting. Those usually require the proper clearance on the exhaust valve. I don't know if you're dealing with that, though.

Without a compression release to deal with, the engine sould turn over normally with improper valve clearances, as long as a valve isn't touching the top of the piston.

 

Have you tried spinning the engine over by using anything other than the pull rope?
That is still something I would rule out.

 

I did some checking and apparently this engine does have a compression release for starting (and if anyone here could confirm that's the case, it would be helpful). And if I understand correctly, if I was to check/adjust valve clearance(s) I need to do that when the cylinder is 1/4" below TDC. Is that right?

 

No because I don't know of another method. Advise on that please? Thanks.

 

Well if you would provide better photos or the complete model type and code of the engine...that would help,
But generally there should be a screen in the middle of the engine shroud, that is attached to the flywheel. You can turn the engine by spinning that with hand pressure.
I don't know of your small engine repair guy that looked at it, but if he seen it, and had any salt in the field, I would think he could have had more of an idea than you say he did...
Just trying to help sort out the simple issues here, just as the briggs mech told you, without putting hands on, most things are only a speculative guess...

 

Model Number: 150212
Type: 0122 E9
Code: 070612

Photo shown at this link http://www.briggsandstratton.com/generators-pressure-washers/pressure-washers/detail.aspx?name=3200+PSI+Serious+Duty&id={89656CB2-EEA6-4810-B9BF-F4578C5FD600} as engine appears on pressure washer. Is the shroud (or screen) I need to remove to turn the flywheel by hand the same shroud/screen that covers the starter rope pulley, through which the rope goes through?
(Yes I too would have thought the small engine repair guy to which I showed it to would've been more help, but he wasn't. I understand without hands on, speculation is best we can do here based on descriptions.)

 

with plug out turn through to compression stroke TDC and use a straw in the plug hole to measure and continue to turn 1/4" past TDC. Remove valve cover again. According to the manual for single cyl OHV the intake clearance is .004-.006 and exhaust is .009-.011. The compression release would be on intake so if you find it way high then that could be the problem.

 

Thanks! I'll be taking the opportunity tomorrow to check (and adjust if necessary) the valve clearances. Will post back then.

 

Okay I checked/adjusted the valves. Still have the same issue. Any more ideas what might be the problem?

 

Try this:

With spark plug in place.

Pull out the starter rope until you hit the lockup. Pull just past that point and put a small mark on the rope. Then completely pull out the rope (and I understand it's normal from that point on).

Then let the rope retract to the mark you put on it - no farther in and pull the rope back fully out. Do this several times and see if it locks up at any time.

There could be something in the pull start and the extra drag of the compression is affecting it. This is getting down to the unlikely, though.

 

It just feels/seems so much more like a compression lock-up or drag than a pull rope problem. It seems like exactly (or at least close to) what a hydro lock situation would feel like. The resistance while pulling isn't really in the exact same place all the time, or seem to happen at only one point, but rather seems to occur at maybe three different points beginning and then past the first 10 or 12 inches of pull. It's not locked tight, just excessively hard to pull at these points with the strokes of compression it seems. The rope will pull out all the way, but only after pulling hard and slow through these points of resistance I describe, as the cylinder goes up and down...
But when I pull the plug, all is free and smooth.

 

That's just a tough one to figure from a distance.

In the engine you would have every other revolution as an exhaust stroke = no compression. In the one long pull of the rope you might get possibly three compression strokes, if the first one occurs at the beginning of the run of the pull rope.

The problem is the engine will pull through a compression stroke in normal starting, without any difficulty. The compression release makes for easier starting with the ignition in place and, in rethinking this, even if the compression release is disabled, with the plug wire off, you should be able to pull through that stroke without any problem.

The only thing you're changing, however, with the plug in or out (and the ignition wire out of play) is the compression. There just isn't anything else unless there is liquid in the cylinder. If that was the problem, you should get something out of it while spinning the engine with the plug out. Since you didn't, we have to assume there isn't any in the cylinder.

We could still make a small case for something in the pull start binding under the extra load of pulling against the compression of the engine. And that binding could coincide with the compression strokes.

You can check that by pulling the engine shroud off the flywheel and turning it by hand, as BF suggested.

Other that I just couldn't say. My first impression was it was on the pump side,, but with a free spinning engine/plug out, that brings you back to the engine.

 

I'm still thinking the sheared flywheel key.. I know you don't see this on a pressure washer.. but if the flywheel wasn't tight enough??.. I don't think he's checked it yet??? That's the first thing that comes to mind... Roger

 

Roger;
I agree, it sure sounds like a flywheel key to me. You can't really check them without removing the flywheel. Have a good one. Geo

 

No I haven't checked the flywheel key yet. What is it exactly I need to remove to have access to that? The engine shroud? Not sure what is meant by that. You mean the cover over the pull-rope area? Please elaborate about that if possible. Also, wouldn't there have been some advance indication that the flywheel key was getting close to the point of actually shearing, before it did (if it did)? Thanks

 

Yes, you remove the cover over the pull rope area, then remove the nut on the flywheel and view the key. No, it wouldn't give advance notice... just like a bolt gives no warning before it breaks. Since it does it with the plug unplugged, I don't expect it to be the flywheel key but check it anyway. Make sure you tighten the flywheel nut sufficiently or it will shear the key if it hasn't already.

 

With the plug out, I can pull freely. In regard to that, there doesn't seem to be a consistent consensus among the replies here whether there's much of a possibility that a sheared flywheel key is the problem. But it doesn't sound too difficult to go ahead and check it, so I will, as you suggest I do anyway. Thanks cheese.

 

With an explanation, I'm sure you'd have more of a consensus on the flywheel key.

The flywheel key is critical to the timing of the engine. An advanced spark occurrence will drive the piston back during the pull of the starter. The sheared key happens in two different ways (that come to mind). The key shears when you're pulling on the rope which is pulling on the flywheel, which advances the flywheel on the crank = advanced timing of spark. The other is when the driven component such as the mower blade hits something and the impetus of the flywheel on the engine carries the flywheel past the setting on the flywheel key = advanced timing of spark.

The problem involved with the flywheel key shear/broken is the advanced timing of the spark - nothing else. The most common way to check the key is to remove the flywheel and look at the key. But the easiest/fastest way is to remove the spark plug wire, which takes the ignition (spark) out of the equation.

Since you removed the plug wire and still have the same problem, it's a pretty sure bet the flywheel key isn't the problem on what you're describing at present.

 

One other thing I might mention: Although I've not seen any indication of liquid in any form ever expel from the spark plug hole while cranking while the plug is out, with the muffler removed I can look directly down into the exhaust port and see the valve head there move up and down as the engine is turned. There is a very very slight bubbling I guess you might call it that can be observed around the circumference of the valve head at its seat right at the slight moment the head moves from the seat. I assume what I see is just a little wetness from a little gas in the cylinder. Again, this is very very slight and can only be oberved with fairly close observation. Comments?

 

I'm still stumped about what could be causing this issue. Rope pulls freely when spark plug is removed. With spark plug in, while pulling the rope there is resistance that seems to occur in coordination with the up/down stroke of the piston, this resistance preventing a smooth/full pull of the rope. As mentioned previously, there was no such problem with this engine several weeks before. Then I simply went to use it again and encountered this issue upon first startup attempt, and it remains the same. Still seeking answers/advice on this one.

 

Maybe it comes down to the amount of resistance you're talking about.

Is it more of a put your foot on the washer to get it to turn over or just that everytime you have a compressions stroke (two revs) it pulls harder?

You can't get it to start at all, then?

 

Yes, I definitely need to put my foot on the washer while pulling, as well as in advance of pulling (anticipating and then getting this resistance I've described) to get it to turn over. And I'd say yes that it seems to match your description of every time I have a compression stroke it pulls harder. Not harder with each stroke necessarily, but hard points to pull through with (or after?) each stroke. And no, can't get it to start at all because I can't pull a full smooth pull with these resistance points encountered as I pull.