Kicks Back

Frisco57

Active Member
#1
The 69 B&S on my 68 Bonanza is rebuilt hooked up and ready to go. It's mostly stock except the governor has been removed and I've installed a ARC billet connecting rod #6350 and an ARC billet flywheel #6620. A friend and I have tried to start it but broke the starter rope twice and left us both with sore hands and wrists...It wants to start but kicks back hard! Now what?


IMG_3556 (1).jpg IMG_3531.jpg
 

Itype2slo

Well-Known Member
#2
I
With a stock block, it is not the valve train that will limit you with a cam selection, it is the kick back on the recoil, and then the lifter bores. The cam I have in a Tote Gote Raptor is hotter than the Raptor cam, but the cam card I posed here on OldMiniBikes got deleted along with the build. Note that the stock Raptor cam is hotter than the stock cam. I checked that too, but no numbers to report.

The kazoo carb- I went to a later model pulsa jet because it allowed mounting on that later tank, and used the later model choke lever as opposed to the push-pull button. A Raptor carb has no choke. Sorry for skipping around here.

The Dyno 94SS is very popular and doesn't require billet lifters or strengthened lifter bores, but does require new valves so you can start fresh with lash.

Also look at the 004 grind. Here are the springs for it. The retaining bits are on that same page.

Dyno says you can use the 107 with no special lifter mods, but it might be one to kick back on start. For sure the 108 will kick back, and damage your hand, and cause you to go to the doctor for a sprained wrist, and sell the engine, and get of mini bikes, and move to California. But it does make a hot rod engine, if you use a Mikuni etc.

Note that these cams like more spark advance, so you're going to mess with keys or adjustable wheels.

After a few years, I am still riding the Tote Gote, and winding out the engine against the torque converter like no one's business.


Your post reminded me of this. One of my favorite quotes.
 
#6
what camshaft is in it? most above super stock cams don't have easy spin.
what is the valve lash? too much lash on a stock cam will do away with easy spin[its only about .015 inches].
what is the timing set at? too much timing will make it kick back also.
im thinking more like no easy spin, or timing advance.
 

Frisco57

Active Member
#7
what camshaft is in it? most above super stock cams don't have easy spin.
what is the valve lash? too much lash on a stock cam will do away with easy spin[its only about .015 inches].
what is the timing set at? too much timing will make it kick back also.
im thinking more like no easy spin, or timing advance.
funky ole,
Thanks for the feedback. There's a stock B&S cam in this engine. I don't recall how much valve lash. I'll have to re-check that spec., and the ARC billet fly wheel gives you 30 degrees when keyed to the crank.
 

joshua. c.

Well-Known Member
#8
it might be a broken key or it could just be the timing advance. you did torque the flywheel nut it to speck right? not doing so will brake keys left and right. my built up raptor always kicks if your not careful. Ive found to start an engine that kicks just start it with the throttle fully closed then once it fires give it some gas. it may take a few tries but it saves you from braking your hand. less air means less compression and no kickback. either that pull really really fast so the momentum overcomes the kickback.
 

Frisco57

Active Member
#9
it might be a broken key or it could just be the timing advance. you did torque the flywheel nut it to speck right? not doing so will brake keys left and right. my built up raptor always kicks if your not careful. Ive found to start an engine that kicks just start it with the throttle fully closed then once it fires give it some gas. it may take a few tries but it saves you from braking your hand. less air means less compression and no kickback. either that pull really really fast so the momentum overcomes the kickback.
The flywheel was both lapped and then torqued to spec. I've been a little busy lately with an old farm house remodel but I'm getting close to getting back on the Bonanza/ Briggs & Stratton build. I've now got some things to check and some things to try. Thanks for the info.
 
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