B&S lawnmower engine- OHV 121600

[glockmail]

About 8 years old, and it started leaking oil at the head. I bought gaskets, took apart what I needed, including the valve rocker arms, and replaced the leaking gaskets. I reset the valve lash, it was slightly off on both. Now the engine is very hard to pull start, lots of tension on the pull rope, but it starts on the first pull, and runs fine.

Anyone know what the problem might be?

Is there a compression release that I may have screwed up?

[Mr. P]

About 8 years old, and it started leaking oil at the head. I bought gaskets, took apart what I needed, including the valve rocker arms, and replaced the leaking gaskets. I reset the valve lash, it was slightly off on both. Now the engine is very hard to pull start, lots of tension on the pull rope, but it starts on the first pull, and runs fine.

Anyone know what the problem might be?

Is there a compression release that I may have screwed up?

Just a guess…when you reassembled, something in the rope pull mechanism got misaligned maybe. That’s where I’d look first.

[glockmail]

Just a guess…when you reassembled, something in the rope pull mechanism got misaligned maybe. That’s where I’d look first.

Thanks, but I'm positive that's not it. It's not a friction type resistance, but a compreesion type that increases rapidly, then decreases. I've emailed B&S for help but so far no response (except for a faggoty survey asking how my experience was).

[Mr. P]

Thanks, but I'm positive that's not it. It's not a friction type resistance, but a compreesion type that increases rapidly, then decreases. I've emailed B&S for help but so far no response (except for a faggoty survey asking how my experience was).

Maybe a spring assist then? Donno

Try this site, I get lots of info there, their mods are people in each field....http://forum.doityourself.com/

[trobinett]

First, bring the engine to TDC then piston should travel a 1/4" past TDC, now you can set your valves.

These engines DO have compression releases, they effect the intake valve, they have been known to fail. Not the end of the world, but has the effect you describe.

Some times its just a weak spring on the compression release and you can tighten up the clearance a .001 or so.

Good luck.

[glockmail]

First, bring the engine to TDC then piston should travel a 1/4" past TDC, now you can set your valves.

These engines DO have compression releases, they effect the intake valve, they have been known to fail. Not the end of the world, but has the effect you describe.

Some times its just a weak spring on the compression release and you can tighten up the clearance a .001 or so.

Good luck.

Thanks. I'll try setting the valves at this position.

By "tighten up the clearance a .001 or so", do you mean the intake valve clearance?

[trobinett]

Thanks. I'll try setting the valves at this position.

By "tighten up the clearance a .001 or so", do you mean the intake valve clearance?

Do you have a "tech manual"?

Generally on OHV, Briggs and Stratton recommends about .004 on the intake, I'm saying go to about .003. What that does, is starts the "opening process" just a touch sooner.

Oh, you've checked to make sure there isn't any push rod issues, correct?

Some models use little caps that sit on top of valve stems, did yours have them, and if so, are they still there?

If you don't know, let me know, I'll go into Parts Smart, and check it out for you.

I'm at the shop right now, so make it snappy!

[glockmail]

Do you have a "tech manual"?

Generally on OHV, Briggs and Stratton recommends about .004 on the intake, I'm saying go to about .003. What that does, is starts the "opening process" just a touch sooner.

Oh, you've checked to make sure there isn't any push rod issues, correct?

Some models use little caps that sit on top of valve stems, did yours have them, and if so, are they still there?

If you don't know, let me know, I'll go into Parts Smart, and check it out for you.

I'm at the shop right now, so make it snappy!

I have The Operator/ Owner maunal and a separate parts manual; no "Tech Manual". The owner manual gives valve lash specs of 0.004-0.008 (both) with springs in and piston 0.1" past TDC. I set them to 0.006.

I have little caps and did not lose them. I'm no expert but I've been a shade tree mechanic for 30 years so know better than that.

Gonna try and reset this now while you're available.

[glockmail]

....

Maybe this is where I'm going wrong. I've always defined TDC as piston all the way up, just before the intake opens. When I go past that, the valve opens. So I adjusted them at the end of the compression cycle.

What gives?

[trobinett]

Maybe this is where I'm going wrong. I've always defined TDC as piston all the way up, just before the intake opens. When I go past that, the valve opens. So I adjusted them at the end of the compression cycle.

What gives?

TDC is when BOTH valves are closed(the compression stroke), the next stroke is the power stroke, then the exhaust stroke, and finally the intake stroke. Sounds like you've been doing the adjustment on the intake stroke.

Let me know........

[glockmail]

TDC is when BOTH valves are closed(the compression stroke), the next stroke is the power stroke, then the exhaust stroke, and finally the intake stroke. Sounds like you've been doing the adjustment on the intake stroke.

Let me know........

My old Chilton's Motorcycle Troubleshooting Guide defines it differently. But no, I've been making the adjutments just past TDC, start of the power stroke.

I just set the intake at 0.003 and the exhaust at 0.004, changed the oil, started it up and it caught fire and blew up the neighborhood.



I'm kidding. It actually started on the first EEEZZZZ crank, on last falls gas!

Thanks for your help.

Now what do you know about rototiller transmissions....

[Mr. P]

My old Chilton's Motorcycle Troubleshooting Guide defines it differently. But no, I've been making the adjutments just past TDC, start of the power stroke.

I just set the intake at 0.003 and the exhaust at 0.004, changed the oil, started it up and it caught fire and blew up the neighborhood.



I'm kidding. It actually started on the first EEEZZZZ crank, on last falls gas!

Thanks for your help.

Now what do you know about rototiller transmissions....

Get a mule an plow!

[trobinett]

My old Chilton's Motorcycle Troubleshooting Guide defines it differently. But no, I've been making the adjutments just past TDC, start of the power stroke.

I just set the intake at 0.003 and the exhaust at 0.004, changed the oil, started it up and it caught fire and blew up the neighborhood.



I'm kidding. It actually started on the first EEEZZZZ crank, on last falls gas!

Thanks for your help.

Now what do you know about rototiller transmissions....

Hey, for a fellow DP'er, whats your question.

Lawn and Garden is my LIFE..............

[glockmail]

Hey, for a fellow DP'er, whats your question.

Lawn and Garden is my LIFE..............

Its a Sears rear tine 5HP model, and I've owned it for 20 years, and worked it hard on both NY sod and Piedmont red clay. I loaned it to a neighbor to break up some hard dirt so he culd put a walk in, and it jammed. I don't blame him, as it's got more than a few hours on it, but I was not around to see it happen. I suspect he threw the shifter into revese with the flywheel still turning, or vice versa. It was getting to the point where it spun for a while after the "clutch" belt was disengaged.

I took the belt off and cannot rotate the input shaft pulley in either direction. I suspect I have a broken gear tooth. I have the parts diagram. As it will take a while to get at the transmission (its practically part of the frame) I don't plan on pulling it apart until I have a free weekend, maybe the last one in March, but most likely mid-April. If I have any problems with it then I'll post here or PM you.

Do you think I have a snowballs chance of fixing it or will I be wasting my time?

[glockmail]

Here's the diagram