Guys,

I hope you can help me out. I recently purchased a generator with a 16hp briggs motor Model 303447 Vanguard. I was told it wouldn't start due to a valve/head problem. So I bought a nice set of heads from a running motor and installed them on the engine. Torqued all the bolts, new gaskets and set the valves as per the manual. 1/4" past top dead center on each cylinder. I verified the clearances and triple checked the valves.

I found TDC by removing the spark plug and turned the motor over until the cylinder was at the highest position and no valves were moving (one revolution past when the exhaust and intake move together). I then went past TDC a 1/4". And adjusted as per the manual.

OK so my problem is all I get is a small sputter and it won't start. It sounds like its about to catch but nothing. I don't have an antifire solenoid. To make sure it wasn't the carb I turned the fuel off and sprayed starter fluid but the same effect. The exhaust pipes are warm so I know I am getting some kind of a start. Also it spits some raw fuel up through the carb when it tries to start.

I checked compression and found 30 psi on each cylinder. Spark looked good on each cylinder. I have new plugs.

Again I did buy it used and not running. I really have no other info. Normally I am really good about this stuff but this one really stumping me. Its probably something simple.

I have never heard the engine run. The pistons had carbon on the top of them that I cleaned off. Also the walls looked fine. But I did not get into the bottom end of the engine.

I also watched the valves and they travel up and down fine. So I don't believe it's a cam problem.

Could it be any thing with the governor? I noticed that it holds the carb plate about half open. I tried playing with it by opening and closing the plate while cranking but the same sputtering. I did a static adjustment per the manual and I did a dynamic basic check by removing the speed adjuster nut in case that was it.

Any ideas? I live in Florida and would love to get this motor started in case I need it - if you know what I mean.

Thanks again for the help.

John

Whew. That took awhile to type I bet.
If you only have 30# compression, I believe you need rings, was there any cross hatch marks in the cylinder? You may want to have it bored and rebuilt.

It was 30 on each cylinder exactly. Put what was weird was the first time I set the valves I set them at TDC not a 1/4" past and I had 55psi.

I am assuming that the way I described setting the valve clearance is correct.

I read that the engines have a compression release and that if you turn the engine in a counter rotation of the normal rotation and if you get a kick back the compression is good. I did this and I did get a kick back.

The walls still had some visible cross hatching.

Performed a cylinder leak down on each cylinder as per the manual - 70psi and 90psi (cold engine). I had no air leakage into the oil, exhaust or intake.

Do you guys set the valves by watching the intake and exhaust open almost together and then spin it one more revolution. Followed by going the 1/4" past TDC.

Thanks,
John

To set your valves, both valves will be in the closed position, engine at 1/4" past tdc. Good luck.

Do you set them when the exhaust is closing and the intake is opening or when both are closed.

Or on the next compression stroke?

Set The Valves When Both Valves Are Closed Which Is The Compression Stroke, Remember To Be 1/4" Past Tdc.