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Briggs Engine Rebuild Textbook


tamurmueen

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Gentlemen, and Ladies,

I have a small collection of late 1960s tractors and attachments; I use them regularly, though most of the necessary repairs to date have been done by others.

As a learning experience, I am hoping to rebuild a Briggs 12 HP engine, creating a 16 HP engine from the block - vintage late 1960s.

I have a friend who was planning to take on such a project, and who will be passing on to me the parts he had collected for his project; I will take it on in the not too distant future.

I know almost nothing about this subject, and am interested in first reading a "How-To Book", about how the old engines work, and then am searching for a "Step-by-Step Guide" for executing the task. 

Essentially, I would like to read something a High School student might use as a textbook for a class in Engine Rebuilding and Repair; unfortunately I have no professor.

If your grand-son or grand-daughter were to ask for such a text/guide book, which one would you recommend?

Thank you for your help.

Best, Tamur

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Agree with Bill.  Also, youtube probably has videos that would take you thru the process but be careful to pick someone that knows what he is doing.  I don't know if ZippoVarga has a video that would take you thru the process, but all his are good.  I think you will find doing the older single cylinder engines is pretty straightforward.   There is nothing better than overhauling an engine and then starting it for the first run, i just love that, have done it a few times!  Have fun!

 

Steve

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Thanks, folks!

I've found the Briggs and Stratton Repair Instructions Manual (versions III and IV) on eBay, and have purchased them. I also found an original B&S Parts and Service Data shop binder on Thriftbooks.

I'll read these through, and with the assistance of YouTube, and you all, will embark on this expedition!

Best, Tamur

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I rebuilt a B&S CI 12 HP, Model 300421-0127 last year. FYI, 12 HP engines before date code 7004171 use the old style intake valve P/N 230861, with the old style retainer P/N 68283. Engines after date code 7004161 use the new style intake valve P/N 261206 which supersedes to P/N 394435, with the new style retainer P/N 494553. The valve seat angles are different between the old and new style. If you try to use a new style valve in an old style engine the valve seat needs to be changed. There are some NOS P/N 230861 on eBay.

Also, the crank pin will be out of round and will need to be ground undersize. There is a 0.020" undersize connecting rod, P/N 390306 also on eBay.

If you rebuild it right it will last another 40 years.

If you have any more questions, come on back.

Edited by Bill725
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Thank you!


I splurged and got the undersize connecting rod you recommended. 

I also bought an intake valve, as suggested

I did this after understanding that what you were saying was that the crankshaft would likely need to be sanded down to round, and that then the standard connecting rod would obviously no longer fit!

Will I likely also need an outlet/exhaust valve?

Best, Tamur

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FYI, when I rebuild engines I use all new internal parts except the block, crankshaft, camshaft and cylinder head. I check the governor gear shaft and governor crank bushing for wear. I have rebuilt (3) engines and have not had to replace either yet.

Take the IPL and make a spreadsheet with all the parts you plan to replace. The "original" IPL will give you the old "Made in USA" P/Ns. The IPL on the B&S website will give you the new "Made in China" P/Ns. I try to use the old "Made in USA" parts whenever possible.

The only thing different would be the 16HP standard piston which is P/N 390364 (USA) / 792365 (China). There are some 390364 pistons on eBay.

Don't forget

On 1/20/2022 at 8:21 PM, Bill725 said:

the old style retainer P/N 68283

If you plan on upgrading to the Magnatron electronic ignition, I remove the points plunger bushing and have the machine shop drill and tap for 1/4 NPT plug.

If you need the IPLs or have any other questions or comments, PM me with contact info. Glad to help.

Edited by Bill725
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Thanks, Bill, 

I'll be in touch when I get a chance to open the engine and look at the internal parts. Right now, I'm flying blind!

Best, Tamur

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