B&S 190707 1148-01 Will Not Turn Easily

Well, i'm back. Got a Briggs 190707 1148-01 that has been rebuilt and modified for racing. Put it on a go cart, hooked up to tranny and started. Ran fine. Sounded Awesome. So, I put it away, go back later, and Runs great, then starts making a whining noise, while running, seems to go away as the throttle is lowered down, just at high rpms. So continues like this for about a minute, then stalls. Tried to restart with starter motor, it moves a bit then stops. Can just barely rotate the engine with my hands. So I took it apart, and took the crankcase cover and cylinder head off, and it hasn't seized. Can rotate slowly though. And the starter motor can rotate the engine when the cylinder head is off. Seems to be a tight con rod cap. Did i torque it too tight?

 

what was it torqued to? briggs has a torque spec sheet on their website if you need the exact spec. i'd be inclined to take the end cap back off and check for any damage as well, its gonna be a racing engine, don't want a connecting rod flying.

 

James your post is somewhat aged here but in the event you haven't found an answer to your problem you might want to check this Lawn Mower Racing site out. They do work on the 19 CID Briggs inlcuding modified cams, balancing cranks, carb work, porting the heads etc.

 

Lol, think I found the problem

Didn't tighten the ignition coil screws, so it vibrated loose and magnetized itself to the flywheel

will check it out at school tomorrow, and reset proper gap.

 

wasn't the coil, it was the connecting rod.

http://web.rulex.net/smextreme/seizure.jpg

I will polish the connecting rod, cap and crankshaft, put it together and check clearances.

 

don't polish anthing unless there has been metal transfer. if the initial clearances were not correct you can't polish them to spec. take it to a machine shop and get it sized properly. check with micrometer if you can, plastigauge if you have to. torque to bolt mfg spec not briggs manual. if useing oem rod bolts use briggs specs.

 

Yep, theres been metal transfer. Scoring on the connecting rod and cap where the crankshaft hooks up. Fortunately, my school has a machine shop and thats where I'm working on it. We got micrometers and plastigauge, and yes, There OEM bolts.

I'm home sick today, so i can't check the clearance.

 

don't know what went wrong but the responsibilty for the build always falls back on the builder, not the machine shop. i don't care how much you trust the shop always measure the assembly for clearance and get to know what is normal. i have dealt with two cases of misprinted specs. the first time it cost me a re-assembly, the second time i questioned the spec and i was correct in doing so. saved me a world of hassle. good luck and enjoy the build.

 

I dunno what went wrong, i'm the only one who's touched this engine!! Torqued the rod bolts to the specs in the Briggs and Stratton Single Cylinder "L" Head Repair Manual.

I'll cross reference with the Briggs Site.

The Machine Shop is the class we take, currently we're building a drag racer from a 1989 Chrysler Lebaron and a Stock Race car out of a ford thunderbird.

So far I've rebuilt 7 briggs engines there, this is my first time tackling a vertical shaft though.

**EDIT** Also, anyone know where i can get the decal for this engine? This is what it looks like:

http://web.rulex.net/smextreme/decal1.jpg

I made one in photoshop, looks similar, but better and more fierce:

http://web.rulex.net/smextreme/decal2.jpg
If i can't find one by briggs, i'll just get it printed somewhere

 

if you did the machine work you may have messed up. if you only assembled the motor, and didn't check the fit, you did mess up. it happens. that's how you learn things. then again there may be something else that went wrong. bad oil slinger, bad assembley lube, who knows. finding out is why you're in school. aint it fun ? the decal is not listed as a part. maybe you could have it scanned and die cut from vinyl at a sign shop. in any event, it's better you learn on a briggs than a 100k nitro sucking huffer. just keep having fun with it.

 

Yep, i guess I did mess up! Will check the fit with plastigauge tomorrow.


The only machine work I did was milling the cylinder head, and port and polished the intake and exaust so far.

Could be old assembly lube. Does that stuff expire?

 

you'll get sorted out. it's obious you have a passion and talent for this. just keep plugging away. and read,read,read. when you're finished reading, read some more.