Gloat and compulsion to fix things

Yesterday I swung by the recycling center and there was a complete 5hp Coleman pressure washer sitting in the metals bin. I wrestled it out and into the back of my car, took it home, and cancel all plans for the rest of the day.

I filled the tank half full with gas and tried to start it. No gas getting to plug. Pulled and dis- assembled the carb - looked fine. I put my hand over the intake port and cranked - pressure coming out during compression stroke.

Pulled off the head, everything looks good, pulled off valve spring cover - ahh haa, no clearance on intake valve, keeper on exhaust valve is off.

First the intake valve, take it out and grind down the stem tip until I have about 15 thou clearance, put it back on.

Now the exhaust. I take the valve out and the stem look terrible. It's necked down nearly 1/8" where it rubs against the guide and the shoulder where the keeper lives is all chewed up.

I grind the worn areas down to clean metal, fire up the oxy-ace torch and blob braze over it. I chuck it in the lathe and do my best to true it up. Nothing I'd be proud to show to a real machinist, but better than before. I grind about .015 off the tip of the stem, like the intake valve so I have some clearance. I put the valve back in and button up the valve spring cover.

I make a new head gasket from gasket material, spray both sides with copper permatex, torque it to 25 ft/lbs and put the rest of the engine back together.

Now we have some compression. With just a little bit of tweeking around, it starts and runs great. I hook up the water, fiddle with the nozzle and I have a working pressure washer. I pressure-wash the pressure washer.

What I learned:

Gas engines really want to run.

I get unbelievably compulsed to fix things, especially free things.

What I'd like to know:

Where did the valve clearance go?

Reply to
Jim Stewart
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This is, indeed, wonderful. Great job and a good example where a lathe is quite useful. Congrats. I, also, acquired a military surplus 11 HP pressure washer that was "broken", but the damage to it was limited to a rotten fuel line and a bad kink in the high pressure hose. Try powerwashing your concrete areas.

i
Reply to
Ignoramus906

Reply to
Waynemak

Pretty much a standard B+S repair. Briggs uses such lousy material for the intake valves and seats that it wears fairly quickly. As the valve wears into the seat you eventually run out of clearance.

The exhaust valve stem wear is also classic Briggs. The exhaust valves are made from better material and will usually still have clearance long after the intake valve looses its clearance. But dirt blowing into the muffler and collecting on the valve stem then gets sucked into the aluminum bearings that the valves run on. This then laps the exhaust valve stem down faster than you would believe possible. The dirtier the environment the faster it wears. The worst I've seen is engines mounted on a trailer tongue for pumping liquid cow feed. I know of one brand new briggs that didn't last one winter pumping the stuff. Wayne Cook Shamrock, TX

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Reply to
Wayne Cook

Probably a combination of:

Seat wear

Valve margine wear

Valve stem wear.

The seats on those engines get deeper and deeper with time. Eventually they need to be replaced.

The valve heads get thinner and thinner, eventually they get smaller in diameter too.

A lot of this has to do with materials issues, my dual-sport bike had intake valves that never could hold clearance. When I took the head off, I found the seats were immaculant, the stems were basically unworn - but the valve head had worn so badly the valves were about 75 percent of the diameter they should have been. They were so loose I was able to remove the keepers by hand! =8-O

Kawasaki had a part retrofit apparently - the new valves I put in (I did the exhausts too, even though the were not wearing) have gone about a year now since that repair, and although I check them on occasion, I've never actually had to break the adjuster locknuts loose since installing the new valves.

I think Kaw was trying to cheap out on the intake valves but found that they were wearing so badly, they changed over to the same metalurgy they were using on the exhausts.

Jim

Reply to
jim rozen

What Jim said.

I got one of those deals with a generator , only thing that was wrong was that the U shaped part that holds on to the exhaust spring broke. $15-$35 for a kit with disks instead of U shaped and it runs great.

Some engineers should be slapped hard . Maybe they where trying to prove trickle down economics...? Maybe they were trying to exclude one hard proven way of a disk and two keepers , yeah lets put in a U shaped thingy that just slips in with one motion and doesn't need keepers. Stupid ! Got a nice generator for practically nothing though.

Only problem is that the power won't shut down so that I can use it.

Reply to
Sunworshipper

Yes, ours is probably the only house in town sporting three functioning vacuum cleaners and four "electric brooms", all snatched by me from the curbsides of other towns on trash collection days. And, our home has a central vac system too.

Our town has a "trash collection center". It's not a "dump" but a place where townsfolk haul stuff to and from which it is taken to a real dump.

It has a "goodie table" where all the non-tech folks put appliances, power tools and similar stuff when it's cheaper for them to buy new replacements than pay for a repair.

SWMBO won't let me go there anymore......

Jeff

Reply to
Jeff Wisnia

Do you know about Freecycle? Is there a Freecycle group in your area? This is a Yahoo group where you post offers of things you don't need anymore and people come over and take them off your hands. A great way to redistribute those resurrected appliances...

Reply to
Emmo

I bought a car last year for just about a give away price. It had a miss in it and wasn't running smooth. I got it for about 1/3 of what it should have went for. Turns out someone ground the valves, but didn't shorten the valve stems. Which is critical on an overhead cam engine. The book gave a specific stem height not to exceed or the valves would never close. Got the purchase price of the car back in gas savings in less than a year.

Richard W.

Reply to
Richard W.

On Mon, 11 Apr 2005 09:53:11 -0700, the inscrutable Jim Stewart spake:

--snip of nice gloatable find 'n fix--

...even when the cost to fix them exceeds initial price of a new item. What is it with us?

In some engines, valves and seats wear from grinding on the combustion particulates, additives, the caustic action of the fuel itself, and dirt in the fuel and air. That closes the gaps.

---------------------------------- VIRTUE...is its own punishment

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Reply to
Larry Jaques

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