ring size on a 5hp briggs

[SCROOOFACE]

my friend gave me his older 5hp motor because it was smoking and oil was fouling the plug and the motor would shut off.. i pulled the whole thing apart and when i went to take the piston out, i couldn't.. there is a very small lip at the top of the cylinder that doesn't allow the rings to pass.. the lip only goes around half way.. i can remove the crank and pull it out through the bottom but would rather address the issue at the top of the cylinder.. i'm guessing the rings wore the cylinder down.. what's my next step?? not looking to dump money into it, just trying to get a few rides out of it.. maybe thicker rings, but what size??

 

[creia]

That ridge at the top of the cylinder bore is an indicator that the bore is worn, possibly significantly so. You need to remove it to be able to remove the piston and rings. (We have used 220 grit sandpaper to accomplish this). Do NOT just throw another set of new cast iron rings in there as some have incorrectly advised on this forum over the years until AFTER you have taken some accurate measurements of the bore - top, middle, and bottom. It could be over worn, out-of-round, tapered, or any combination of these. If it is, new cast iron rings will do NOTHING. Boring the cylinder oversize and installing an oversize piston/ring set is expensive, and is not cost effective on an aluminum "Kool Bore" engine. If you want to get some more use out of the engine, a "band-aid" repair that we have used successfully is to install a set of new "chrome" rings. They have additional "expander" rings that go under the piston rings that get a better "bite" (seal) against the cylinder wall. They will improve compression and reduce oil consumption.
Michael

 

[OND]

Its natural ring groove wear from the piston constantly going up and down, there is a tool to cut this out but I haven't seen one in years. Good Luck, maybe someone else knows a better trick to cut this out.

 

[SCROOOFACE]

thanx for the info.. so do i need specific size rings?? i see +.010, +.020 etc.. on ebay.. some say oversize scraper rings included...or do i have to measure the cylinder and go from there to see what additional size is needed??

 

[OND]

You probably need to measure, but alot of times I buy .010 over size rings and file fit them to the cylinder. But you have to measure the top, middle and bottom of the cylinder.

 

[SCROOOFACE]

You probably need to measure, but alot of times I buy .010 over size rings and file fit them to the cylinder. But you have to measure the top, middle and bottom of the cylinder.

thanx again... when looking on ebay, i see the rings for my engine model then i see the same ones with a different part number that are cheaper and both auctions say fits all 3-5hp briggs engines... are they the same rings with different part numbers?? or do all 3-5hp briggs engines use the exact same rings?? i also have a 3.5hp tech on a mini that smokes like a chimeny... are those rings going to fit on there as well?

 

[creia]

Before you purchase or install ANYTHING go to Ebay and enter the search words "Briggs and Stratton Service and Repair Instructions". You can get a good used copy for $ 10.00 shipped. It will answer all of your questions and save you a lot of grief, frustration, and (especially) MONEY. It is very educational and written in an easy-to-understand manner. My son started with one of these 4 years ago (his very first repair manual), and three years later after taking all of the Briggs courses and passing his tests he became a Briggs Master Service Technician. Out of all the repair manuals in his library, this manual is still the one he refers to the most.
Michael

 

[creia]

thanx again... when looking on ebay, i see the rings for my engine model then i see the same ones with a different part number that are cheaper and both auctions say fits all 3-5hp briggs engines... are they the same rings with different part numbers?? or do all 3-5hp briggs engines use the exact same rings??

A 3 HP and a 5HP take different rings! Do not buy from a seller that makes a claim like "fits all 3-5 HP engines"!ut: I would advise purchasing ONLY genuine OEM Briggs rings in the original Briggs packaging.
Michael

 

[creia]

You probably need to measure, but alot of times I buy .010 over size rings and file fit them to the cylinder. But you have to measure the top, middle and bottom of the cylinder.

This is a legitimate technique ONLY if the bore is worn close to "reject" size or just past specs. We have done this in some engines with success. You will ONLY know, however, if you MEASURE the bore FIRST. In more worn engines the "chrome" rings I mentioned in my other reply will provide you with a little more running time.
Michael

 

[125ccCrazy]

with the ridge in the cyl I'm confident the valve guides are worn also, so with that being said a set of rings would only slightly improve the problem.. you would be better off looking for another engine or look on ebay for a new long block and use your external parts on it.. Just before I read this post I popped the head off an engine and it has the same issue, the cyl is ridged at the valve area, that's the side that takes the most force as the piston moves up..

 

[SCROOOFACE]

was looking on craigslist and came across this... i paid what a set of new rings would cost.. the guy was selling it because water got in the carb and it wouldn't start... cleaned everything out, including the rusty ass tank, now i'm in business... same motor as the other one just newer.. by the looks of the inside, it's hardly been used..

i still plan on fixing the other one also.. a guy can never have enough motors...

 

[Boomstick]

Good score, and the bore on the other one is really iffy. With that prominent of a ridge, it might end up as scrap, or as a beat-it-till-it-blows engine once put back together with the stuff that was already in it.