Idles smooth, doesn't at higher rpms...??

[dart451]

Thank you KE4AVB! I think the newness of the engine and tiller has thrown me off! I couldn't imagine anything being worn out with such a new looking machine! But, the "NO OIL" should have been a dead giveaway! Just out of curiosity, how much would your labor be on a slant OHV engine like this? I've rebuilt L- Heads but not an OHV... KE4AVB, curious...how will I see any damage by taking the head off?

[dart451]

Ok, must have screwed up the compression test! I took off the exhaust pushrod and did another compression test. First pull about 50psi second, 80psi. So, I think the compression is ok. I must not have had the hose tight the first time i checked compression! So, I'm thinking the next test is the spark tester. What should I see on the spark tester while the engine is running? Should I see gaps in the spark? Thank you.

[Arkie]

You will be watching for spark consistency. When the engine stutters try to see if the spark gap intensity changes. Run the engine as slow as possible to get a miss. Higher rpm,s will be harder to detect a spark loss.
I've also used a 12v battery a a inductive pickup timing light to watch for erratic ignition by watching the light,
spark or timing light will not flash right when the engine misses. Not an easy task but if you can get it into a dark place when viewing the briggs spark tester you will get a better view through the little window.

You also have to option of throwing a clone magneto on the unit. I think the part number is MAYBE 796964 at about $13.
Here is an example link of the magneto.
https://www.ebay.com/itm/Ignition-Coil- ... SwMZJZeZYq


Note that I said example. Do your own re-search for part number and vendor.

[dart451]

Thanks Arkie! I only have the little bulb type spark tester but will have the Oregon spark tester here tomorrow. I also ordered the magneto to have it on hand...you are correct on the part number!

[dart451]

Well, tried out my little spark tester today while the engine was running...just can't really tell if it's missing a spark at low idle! I even used a magnifying glass to watch it... Oh well, should have the magneto today to through on it...we'll see if that fixes the miss!

[dart451]

UPDATE:
Well, I installed a new magneto on the engine, gapped it properly...no change in the miss! I think I'm about done...

[rrrhre2s]

1. You said it was dry of oil when you received it ?
2. Customer said it was leaking badly ?

Where's the oil leaking at ?

Maybe it has too much blow by forcing the oil out of the crankcase.

It sounds a lot like a sticking exhaust valve.

In the old L head days I used to run a little 2 cycle mix through the engine running at max RPM and sometimes they would smooth out.

It was only temporary most of the time... The valve usually stuck again fairly soon.

rrrhre2s

[dart451]

The oil was running out of the three filler caps on the engine. One on the top (filler side), one below that and one on the other side of the engine. All three were loose as a goose when I got the machine.

[KE4AVB]

Thank you KE4AVB! I think the newness of the engine and tiller has thrown me off! I couldn't imagine anything being worn out with such a new looking machine! But, the "NO OIL" should have been a dead giveaway! Just out of curiosity, how much would your labor be on a slant OHV engine like this? I've rebuilt L- Heads but not an OHV... KE4AVB, curious...how will I see any damage by taking the head off?

Been busy and missed this.

Sometimes you can't see the damage easily but with calipers and taking at two measurements at the top, middle, and bottom of the stroke you should notice if there is considerable wear. As for labor it about the same as a L-head rebuild; same work just on a different engine.

I am working on Kawasaki that has bite me. At first it looked good at a glance (I didn't measure it) and with rocker arm locator pins broken I was thinking a case of them being broken. The customer said he loan his mower out and it came back not running; never mention it smoking before hand. It is smoking like a freight train now with the new heads. After further check I found oil in #2 cylinder so I pull the engine again. Upon pulling the head and measuring I found has minimum wear of .012 at the top of the stroke. Strange that I can't feel a wear ridge so going double check myself this morning. Any way I do know the ring end gap is way pass max specs and with the engine coming in with only 8 ounces in it and oil in the exhaust I should done a better job checking things. I assumed they just drain the oil due to leaky float valve with I did find. That I get for assuming things.

This makes the second engine in the month that has got me. The other is a Kohler that been sitting a while. The it would run as long they were putting into the intake. The fuel solenoid wires were gone, the wiring harness cut back. With this Kohler it had one those must have solenoids as the main jet is part of it. Well after getting the solenoid, cleaning the carb, and removing a half gallon of water from the fuel tank I got it started to only find that the governor is shot. This wanted only wanted the engine to run. Well it does as long as I cripple the governor to prevent extreme run away.

Boy I hate the customer keeps bring in junkers ie ones that been sitting for years because they don't to buy a new mower.

[dart451]

This guy is taking the tiller back east next week so he's good with it missing a bit. Wouldn't have time to do any more checking anyway but I think your right about things being worn in places I can't check easily! Thanks for the story of your recent engine disasters! I don't get many but when you do, you feel a tad inept! Thanks again!