7hp briggs on a craftman pressure washer. Can't pull (compression)

[tucolawn]

Hey All,

New to the forum. I have a 7 hp craftsman pressure washer with a briggs OHV engine on it. This is about 6 years old, and it has been giving me trouble for quite some time. As of late, I am simply unable to pull the engine to start. It definitely seems and sounds like a compression issue as I can pull slowly and hear and feel the air in the engine, and then move to the next stroke.

So, after lots of research, I came to the conclusion that this is likely valves being off, or a broken compression release. Since I'm not sure about the compression release, I decided to tackle the valve adjust (what an oily mess). I'm at the point where I'm trying to find 1/4 past TDC, and also adjust the valves. What is driving me crazy is this torx (or hex?) screw in the center of the valve rocker adjusters. I can not find a torx or hex that fits in there! Is it some special non-standard size? I'm somewhere between too small and too big with I think was a T10 or T15 torx. I have several torx and hex sets, and i have gone through nearly all of them. It just doesn't make sense. Never seen a bolt head this size. I also don't understand what that screw does, as I can still crank the adjuster nut up/down and even remove it.

Thanks much for any help on getting this engine running again. I really need the washer right now.

 

[reynoldston]

I have adjusted valves on Briggs engines and I can say I don't remember ever having a problem with wrench sizes. You should be able to tell the difference between hex (allen) and torx because they look a lot different. I got thinking about my torx sets which I have several sets of. All my sets go 10,15,20 etc. like you said so I don't know what you have? There is a lot of Briggs experts so maybe one of them can help you or like you said a special wrench??

 

[pugaltitude]

Hey All,

New to the forum. I have a 7 hp craftsman pressure washer with a briggs OHV engine on it. This is about 6 years old, and it has been giving me trouble for quite some time. As of late, I am simply unable to pull the engine to start. It definitely seems and sounds like a compression issue as I can pull slowly and hear and feel the air in the engine, and then move to the next stroke.

So, after lots of research, I came to the conclusion that this is likely valves being off, or a broken compression release. Since I'm not sure about the compression release, I decided to tackle the valve adjust (what an oily mess). I'm at the point where I'm trying to find 1/4 past TDC, and also adjust the valves. What is driving me crazy is this torx (or hex?) screw in the center of the valve rocker adjusters. I can not find a torx or hex that fits in there! Is it some special non-standard size? I'm somewhere between too small and too big with I think was a T10 or T15 torx. I have several torx and hex sets, and i have gone through nearly all of them. It just doesn't make sense. Never seen a bolt head this size. I also don't understand what that screw does, as I can still crank the adjuster nut up/down and even remove it.

Thanks much for any help on getting this engine running again. I really need the washer right now.

Whats your model type code?

You could try the valves but my thoughts would be a problem in the pressure washer pump before the engine. ( I could be wrong)

The centre lock screw could be a 4 mm allen key screw if the 20 torx does not fit in.

slacken the middle screw off then turn the adjuster nut which I assume is a 5/8 socket or spanner size?

Follow link and bottom of page to adjust.
Servicing Engine Valves | Briggs & Stratton

Gaps could be 0.004" - 0.006" depending on model.

 

[reynoldston]

OK I understand the wrench's now. Allen wrench sets come in two sizes MM and SAE.

 

[Fish]

btw, it is 1/4 inch past top dead cylinder, not 1/4 revolution.

 

[tucolawn]

Thanks for the quick replies!

Where can I find the model type of this briggs engine?

Also, I hear what you guys are saying about the allen/torx, but I guess at this point I need exact specs, because I've tried everything I have and I do have complete sets of both hex keys and torx. Is this an american and metric sizing with hex keys or torx that I might be missing? Pretty much everything I have is metric, as I rarely need American sizes to work on most of my stuff.

About the pressure washer pump being the culprit, I wonder if this is true. The washer had been doing that rough idling (when not operating the pump / trigger off), where it would engage and disengage constantly until the trigger was pulled and then it seemed to work OK. The reason I thought it was the engine was because of the feel of the pull. I can pull it, but if I try to pull fast , it will stop up. I then have to keep steady pressure on the cord as I can hear air moving, and then I can pull further. Also, if I take the spark plug out, the engine turns very easily. It was after I pulled the plug and was able to pull easy, that I figured it was some engine compression problem.

 

[tucolawn]

OK I understand the wrench's now. Allen wrench sets come in two sizes MM and SAE.

I bet that's it if it's a hex key , and not a torx. So many video show those screws being torx. I have stared at these tiny bolts in the sun and everything, and I still can't tell for sure. I think I see a sharper point which would indicate torx, but since torx just just one size range (i think), the it must be hex key.

 

[Rivets]

Engine number should be either on the valve cover or a plate over the muffler. Post them and I will find you a manual. Most newer Briggs use Torx lock screws.

 

[Fish]

My money is on torx

 

[reynoldston]

My money is on torx

He was saying size between 10 and 15. now that is small for torx. Now I have several sets of torx bits and just don't see anything in them sizes? What sizes do your torx bits come in between 10 and 15? I couldn't find anything on the web also? I have never looked into this before seeing I must never needed them sizes? Now we are talking about the male torx bits not the female style sockets which use different size numbers.