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Old 09-12-2019, 10:02 PM
madprofessor madprofessor is offline
Join Date: Sep 2019
Location: Jacksonville, Florida
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Everybody seems determined to make you split the case on your brand new engine, and it doesn't seem you're ready for any machining or for that matter any real engine rebuilding. Start basic, and with that TC you can end up with some serious kick without even getting greasy.
BASICS: Throw out the factory "box" air filter for a billet venturi (not flat) intake adapter for a high flow (usually a cone shape) air filter, and do use the dust jacket on it, they're hard to clean right. Throw out the factory "box" muffler for a header pipe threaded for a screw-on muffler. NOTE that the muffler will stifle you right back to near square one, it's only for if neighbors and police force you to use it. Order a matching set of main and idle performance jets for the carb, takes one little wrench and a Phillips head, and forget about changing the E-tube. Disconnect all the hardware on top of the engine for the governor, and run your throttle cable direct to the carb. Voila! You're now running about 10 hp., and never had to split the case. If you feel like pulling off the flywheel (and have a good INCH/LBS torque wrench to put it back) you can order a timing advance (offset) key for more performance, less than $10 for a pack of three of your choice. I used a #7 (8.4 degrees advance)(1.2 degrees per number). Drive/driven sprocket ratio is everything in determining power vs. speed. Regardless of the specific tooth count, figure the ratio only. A 12/60 set like I'm running (1:5 ratio) makes way too much top end, it's terrifying. Conversely, a 10/72 set (1:7.2 ratio) would have a lower top end, but be stronger on acceleration. bob58o is correct about the front (drive) sprocket being cheapest to replace, start there. More teeth there will give higher top end, with less low end torque. Look online for a set of mods that includes some of the aforementioned stuff, and compare to buying individual stuff, get what's less costly, just get the right stuff.

---------- Post added at 11:02 PM ---------- Previous post was at 10:52 PM ----------

Adding on: Maybe it's up there somewhere, but I didn't notice anywhere that you were advised to replace the factory iron flywheel with a billet aftermarket wheel. If you keep your factory valve springs, they'll prevent a disaster of ungoverned rpm's gone wild by starting to "float" above 5K rpm's and preventing too much rpm. Putting on heavier valve springs without a billet flywheel replacing the factory iron, the rpm's can spool up high enough to make the factory flywheel blow apart and send shrapnel through the case, your Levis, your socks, and guess what, your leg. Doctors will be splitting your own case to replace parts inside.
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