Briggs and Stratton 5hp (Flathead) problems

[Sparkwizard]

If you want higher compression, I have a spare Model 10 4 horse head that will bolt right on. It does raise the compression, but it also reduces flow.
$20 shipped.

 

[John Roger]

id rather just sand down the block/head

 

[Denny]

You’re better off just advancing the timing to around 45-50 degrees. Raising compression you will hardly even feel.

 

[Hellion]

hey I got a Briggs and Stratton 5hp with a custom muffler and a 21mm carb and its kinda being weird it sometimes runs and when it does its a smoker the second you hit the gas

Did you ever get this sorted out? Until you do, the rest of what you're planning is moot.

If you want decent power, look at the way they build the Raptor racing engines. They essentially use a hopped up Pulsa-Jet tank mounted carburetor. The whole thing looks “factory garden tiller engine” except for the deletion of the recoil starter and the header pipe. The air cleaner is a simple foam tube, usually.

 

[John Roger]

Did you ever get this sorted out? Until you do, the rest of what you're planning is moot.

If you want decent power, look at the way they build the Raptor racing engines. They essentially use a hopped up Pulsa-Jet tank mounted carburetor. The whole thing looks “factory garden tiller engine” except for the deletion of the recoil starter and the header pipe. The air cleaner is a simple foam tube, usually.

I think I just have to tune the carb in the pictures there was no oil Residue on the head it was pretty clean there than bits and pieces of the gasket it was alright i ordered the wrong carb and this one worked alright on a stage 1.5 predator 212 so I think I just have to tune it
right now the carbs specs are
105 main
out of 5 slots in the needle it’s in the 3 position (the popping and smoke was in the 2 top ring
and no idea the idle jet I can try swapping it out tomorrow also how would you advance the timing would you just move the ignition coil?

 

[John Roger]

Also I can’t find any raptor engines at the moment I was looking for some or some 5hp I/C engine

 

[John Roger]

also if i was going to use nitromethane i would have to buy a 1 gallon jug of 99.9% nitromethane and a 99.9% jug of methanol and do a 90%nitro and 10% methanol and i would have to get a plastic gas tank because it would rust the tank within a week (ask how i know)

 

[Sparkwizard]

Ebay usually has a Raptor or two for sale

 

[John Roger]

i prefer Facebook marketplace

 

[Sparkwizard]

i prefer Facebook marketplace

But most of the old guys with most of the old stuff list them on Ebay, that is why I suggested Ebay.
That, plus, I am an old guy and I buy a lot of old junk on Ebay.

 

[John Roger]

What do you all recommend for a Briggs and Stratton 5hp for the carb tune main jet needle idle btw it’s a 21mm carb

 

[Sparkwizard]

I can't help you you there. I do not use slide carbs.
Tillotsons are much easier to tune.

 

[Hellion]

Also I can’t find any raptor engines at the moment I was looking for some or some 5hp I/C engine

I did not say get a Raptor, I just said emulate it. The 5 H.P. I/C engine is the next best thing of course.

 

[Sparkwizard]

The major difference between an old Raptor and an I/C block is the I/C has a hole drilled for the governor shaft.

 

[John Roger]

I am looking for an 5hp I/C right now I just want to get this thing fixed first

 

[John Roger]

Hey i swapped back the predator 212 and it runs just fine i was wondering i have a 55 tooth sprocket and im trying to get better speed would a 48 tooth be to small at the moment it hits 39 and just tops out in like 6 seconds

 

[John Roger]

Predator 212 specs 21mm carb aluminum flywheel gov delete 22 pound valve springs and a good looking muffler

 

[Edwin Spangler]

a good looking muffler