18.5 BS Rebuild

Goober11

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I have a 18.5 Briggs eng. Model 31P777-0293E2. I have not had this mower long just got it early spring. Did not run. Plug wire end pulled off an gas in the oil. Fixed plug wire changed oil an put cut off on fuel line. Was running fine but did use a little oil. Now it has gotten worse. Gas in the oil did not help. I would like to rebuild it. This would be my first small engine rebuild. Is there a rebuild kit that I can get. or do I need to order each part I need . I am retired Diesel mechanic worked on road tractors. Thanks.
 

Goober11

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Thanks Scrubcader10.

I looked at that site before I posted for help. That may be were I will have to do. I have used them before.
 

Rivets

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Having taught small engine repair and rebuilding, here are a few tips to help you out.
1. Decide for sure what you want to do if your engine is beyond rebuilding. I’ve had people pull an engine apart and then decide they don’t want to rebuild. You now have an engine that will cost you to put back together or you are now either going to junk everything, engine and unit.
2. Set a dollar limit you want to spend. Before ordering any parts, have a complete list of what you need and check it four times.
3. Go through every part and measure everything at least twice. More than once I’ve seen people miss measure or forget to measure parts and find out they need to spend more money because something is not in specs.
4. Don’t, I repeat DON’T set a time limit if this is your first attempt. Will only cause a nightmare down the road.
5. Find out if you have a good machinist in your area who can cut cranks, bore or hone cylinders and do valve work. Need to know what expenses you may run into.
6. If you decide you really want to rebuild, check to see if a short block is available and cheaper than you doing all the work.
7. Don’t rely on your own knowledge, come back and ask questions. We are here for a reason.
8. Personally I would get any parts needed from a local dealer. If you order from him you have a valuable resource if help is needed down the road.
9. This manual will help you out. https://drive.google.com/file/d/0B6NaqjIxWV1ybEN0LWo3azl6OUU/view
 

Tinkerer200

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Make sure your oil burning problem isn't a blown head gasket first as this is common with this engine even to the point of removing the head first. Some check by running the engine with the valve cover removed and looking for blow by into the push rod gallery which is where it will leak IF that is the case. Do this where oil blow out is not going to hurt. Shouldn't be much. Some say to remove the oil dip stick after the engine has been up to operating temp. then stop, and if smoke comes out dip stick, you have a leaking head gasket.

Don't need a new piston unless it is scored or you oversize which is going to be expensive. Same with crankshaft unless it is scored and again, finding a shop which turns small engine crankshafts undersize may be a challenge and expensive. IF you were to oversize cylinder and turn the crank and all the associated parts needed you will have most if not all the cost of a new engine and no warranty.

Walt Conner
 

Goober11

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Thanks Rivets, That is a good check list to go by, and thanks for the link to the manual. I have another mower to use so no time limit on the rebuild. Looks like I need to pull it down to real see what I need to repair it. Short block or parts to rebuild. Local parts dealer in town I deal with they will have anything I need for the job. Brother-in-law has a machine shop if I rebuild.


Timkere200 Thanks for the heads up on checking the head gasket. That would be great if it was bad. I had to put one on my 19.5 BS that is in my John Deer. That was a lot easier than a rebuild. I think you are right on the machine work. If it need all of that I would get another engine.

THANK YOU RIVETS AN TIMKERE200 for all the help with is. That is way I posted to this form.

Terry Goode
 
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Hello Goober.... Yes a head gasket is in order for your engine..... Check the cylinder for scoring when you pop the head off....

There is a reason for the gas in the oil.... Mainly the head gasket....When running the engine the gas will go into the crankcase VIA the pushrod valley. It will blow at the pushrod valley / chamber or the carb needle is not seating right. If you have a fuel pump then look at it good and see if oil is around it ........

Are you the same Goober that was on here a while back ???? We helped a Goober one time with a head issue and I advised him about a valve guide cause he had a bent push rod.....

Same one ???

Let us know Mon Ami ~!~!
 

Goober11

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Hi Boudreaux,

Yes the same Goober. Got that engine fixed with all the help from everyone here. That was not my engine just helping a friend out, but I learned a lot. If we ever get some dry weather here I will check the head gasket. I only have a small shop an a golf cart I am working on is taking up space. Will keep everyone posted on what I find.
The other engine you help me with did have valve guide move. Found a good used head did a valve job on that a the other head. Running good now
THANKS EVERYONE
 
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Goober11

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Sorry it took so long for a Up Date. Tinkerer an Boudreaux you were right it was the head gasket. Replaced head gasket. Changed oil an filter, Air filter, plug. Ran it a for about 40 minutes picking up leafs. It did fine no smoke and had more power also. Again THANK YOU for all the help.:thumbsup:

One more note I picked this mower up in the spring for $225. Troy-Bilt 42 inch cut with a bagger . So with 2 belts a PTO cable and head gasket, tune up I have a mower that I can pick up my leafs an do not have to rack any more. Not a bad deal.
 
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Sorry it took so long for a Up Date. Tinkerer an Boudreaux you were right it was the head gasket. Replaced head gasket. Changed oil an filter, Air filter, plug. Ran it a for about 40 minutes picking up leafs. It did fine no smoke and had more power also. Again THANK YOU for all the help.:thumbsup:

One more note I picked this mower up in the spring for $225. Troy-Bilt 42 inch cut with a bagger . So with 2 belts a PTO cable and head gasket, tune up I have a mower that I can pick up my leafs an do not have to rack any more. Not a bad deal.
Thanks for the update Goober.... Glad you got it going...... Don't be a stranger !!!!!!
 
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