Briggs aluminum bore rebuild

[jake22si 5]

I got a 5hp briggs 130202 engine that sucked up some rust. The cylinder is scored. Are these worth rebuilding or is it now scrap? I guess the question really is can these cylinders be properly bored without breaking the bank.

[MarkPalmer 81]

Unfortunately if the Nikasil coated aluminum bore is damaged, the only way to repair it is to have an iron sleeve pressed in which costs more than what the engine is worth.

-Mark-

[Callen 64]

They can be bored .010,.020 and.030 over. Just make sure you use a Chrome coated piston in the cool bore cylinder.

[MarkPalmer 81]

They can be bored .010,.020 and.030 over. Just make sure you use a Chrome coated piston in the cool bore cylinder.

Can you explain how this works? From what I understood the Nikasil coating is only a few thousandths of an inch thick, and if its removed by cylinder boring or honing its gone leaving only iron/chrome ring to aluminum bore contact. I'm not sure what a chrome coated piston would do when in normal operation the piston should never come in contact with the cylinder. I have (new to me) read of a few places that can re-plate these cylinders, but the cost is around $200.00 on top of the machine work, a bit prohibitive for anything but a very rare or collectible engine.

-Mark-

[Docwheelhorse 2,689]

Hi---let me start by saying I'm a big briggs fan... with that out of the way I hate to tell you but the motor just probably isn't worth rebuilding..... I have tore into a ton of these 5's and most often the crank bearing surface in the block is tired and the rod is tired and so on and so on. I wouldn't bother trying to bore it and do it right---unfortunately a new replacement engne can be had for not very much more than putting together this motor.

On the other hand I have taken several of these with scored cylinders and ball honed them LIGHTLY and put in new chrome rings and gotten several more years of service out of them. Thats what I would do---clean it up, re-ring it, ignore the scoring if its not ridiculous and keep on truckin!

Tony

[MarkPalmer 81]

Hi---let me start by saying I'm a big briggs fan... with that out of the way I hate to tell you but the motor just probably isn't worth rebuilding..... I have tore into a ton of these 5's and most often the crank bearing surface in the block is tired and the rod is tired and so on and so on. I wouldn't bother trying to bore it and do it right---unfortunately a new replacement engne can be had for not very much more than putting together this motor.

On the other hand I have taken several of these with scored cylinders and ball honed them LIGHTLY and put in new chrome rings and gotten several more years of service out of them. Thats what I would do---clean it up, re-ring it, ignore the scoring if its not ridiculous and keep on truckin!

Tony

This is about the same I do with any small engine I get. I'll deglaze the cylinder lightly and then inspect and measure the bore and clean up the piston. If the bore is within tolerance and new rings don't show too big of an end gap, I just install the new rings and go. I have put together many engines that still show some light cylinder scratching/scoring after being deglazed, and they ended up running fine.

-Mark-

[Callen 64]

Mark,

Briggs aluminum cylinders aren't coated. The Chrome coating on the piston prevents cold welding on dry starts (long sitting periods). The wear characteristics of the ring/cylinder wall isn't much different than the crank spinning in the alum bushing in the block.

[MarkPalmer 81]

Mark,

Briggs aluminum cylinders aren't coated. The Chrome coating on the piston prevents cold welding on dry starts (long sitting periods). The wear characteristics of the ring/cylinder wall isn't much different than the crank spinning in the alum bushing in the block.

Thanks for setting me straight Callen. All this time I thought those engines cylinders were coated, as a instructor in a military small engine training course told me they were. Guess you can't trust all your teachers

-Mark-

[SousaKerry 502]

The old Techy H series motors were never coated and some of them ran very well for many years with proper maintenance others not so much :confusion-scratchheadblue:

[Coadster32 793]

Maintenance if definatly key as far as longevity goes. Sometimes accepting a less than perfect rebuild is the best way to go to keep something original, (and keeping costs down). If you end up giving up a little compression, it's normally not a big deal. 4hp is alot of power for sure.