no compression on Craftsman Mulcher, Briggs & Stratton flat head lawnmower.

[ggrigo33]

If the valves are settled right and you have new rings, then it's down to the head and gasket.
1. Is the head cracked ?
2. Get a new head gadget ?

I'am in the UK happy to Skype don't know if time different's will get in the way????

I do have a new gasket installed and there are no cracks on the head or rest of the body.

I think skyping would be great. there is 5 hours difference between your and my time. how about over the weekend? my morning and your evening?


@Michael72

I did make sure the clearence is good after lapping. Infact if all it is probably a bit more than it should be. Last time I tested the compression I had the crankcase open. I mean does it matter? Piston rings should maintain the seal regardless if the crankcase is open or not, at least what I think.


I am going to try to add compressed air to make sure for sure that the valves are good.

Just in case if it is a ring issue, what should I do? I do stil have old ring set that I took off.

The funny part is that it was a working endinge and now...not so much. I mean the main reason why I decided to take it apart is to learn how things work and I am definatelly learning quite a lot of new things lol.

 

[Michael72]

Its all a learning curve....ok, ring/s wont seal off 100% with dip stick out you will prob hear a slight gurgle but thats all... any more and there is issues..have a quick look at valve springs ...just to make sure all is where it should be...if gasket and valves are ok and no muffler or manifold leaks which i doubt it must be a ring issue... I have no doubt you ordered the correct piston/rings....question is, did they give you the correct ones :smile:.... if you take head off then place your old ring into the cylinder, down about 1/4 inch (keep parallel to top of cylinder)with feeler gauge measure what gap is left between both ends if you follow... repeat process with new ring and if its more than your old ring then theres your answer....:thumbsup:

 

[ggrigo33]

Its all a learning curve....ok, ring/s wont seal off 100% with dip stick out you will prob hear a slight gurgle but thats all... any more and there is issues..have a quick look at valve springs ...just to make sure all is where it should be...if gasket and valves are ok and no muffler or manifold leaks which i doubt it must be a ring issue... I have no doubt you ordered the correct piston/rings....question is, did they give you the correct ones :smile:.... if you take head off then place your old ring into the cylinder, down about 1/4 inch (keep parallel to top of cylinder)with feeler gauge measure what gap is left between both ends if you follow... repeat process with new ring and if its more than your old ring then theres your answer....:thumbsup:

hmm, good idea i'll try that

 

[ThaxtexGM]

I do have a new gasket installed and there are no cracks on the head or rest of the body. I think skyping would be great. there is 5 hours difference between your and my time. how about over the weekend? my morning and your evening? @Michael72 I did make sure the clearence is good after lapping. Infact if all it is probably a bit more than it should be. Last time I tested the compression I had the crankcase open. I mean does it matter? Piston rings should maintain the seal regardless if the crankcase is open or not, at least what I think. I am going to try to add compressed air to make sure for sure that the valves are good. Just in case if it is a ring issue, what should I do? I do stil have old ring set that I took off. The funny part is that it was a working endinge and now...not so much. I mean the main reason why I decided to take it apart is to learn how things work and I am definatelly learning quite a lot of new things lol.

Yes Skype over the weekend

Email me tony.thompson@thaxtedgardenmachinery.co.uk

Hopeful I spelt all that right!! No glasses on lol

 

[ggrigo33]

Yes Skype over the weekend

Email me tony.thompson@thaxtedgardenmachinery.co.uk

Hopeful I spelt all that right!! No glasses on lol

sounds good.

by the way so i put old rings back on the piston and lapped valves a bit more to make sure there is no leak. No change... I think last thing I have left to do is to hone the cilinder and see if it helps, maybe i messed it up on some micro level, not visivle to the naked eye. If that doesn't help i am giving up on this engine.

ps.

will oversized rings help? I know B&S have oversized rings too.

 

[Michael72]

sounds good.

by the way so i put old rings back on the piston and lapped valves a bit more to make sure there is no leak. No change... I think last thing I have left to do is to hone the cilinder and see if it helps, maybe i messed it up on some micro level, not visivle to the naked eye. If that doesn't help i am giving up on this engine.

ps.

will oversized rings help? I know B&S have oversized rings too.

Hmmmmm :smile: Over size after a cylinder polish yes... but if mower was working fine before the op there should be no need....did you put old rings back on old piston?...are the rings in the correct order?.... no scoring to cylinder? :confused2: Cam re-installed correctly?....if you pop in your old piston and rings and check for compression then :confused3:

 

[ThaxtexGM]

sounds good. by the way so i put old rings back on the piston and lapped valves a bit more to make sure there is no leak. No change... I think last thing I have left to do is to hone the cilinder and see if it helps, maybe i messed it up on some micro level, not visivle to the naked eye. If that doesn't help i am giving up on this engine. ps. will oversized rings help? I know B&S have oversized rings too.

Skipping you now

 

[Michael72]

You sure there's not a big gaping hole in the block somewhere (Oil on floor)....new ring n piston then no compression...put back the correct old gear...