I finally joined!

[Tyler6357]

Thank you Tyler! I'm going to wait until I get my pile of head-gaskets, and then do a before/after comparison of my dome head vs squish head (both are the same volume) and stick with the better performer.
As an update, I scored a new, slightly dirty Cranbrook at Wally for $52! Do I need another bike? NO! BUT... I want those rims off of it- MUCH heavier duty than the wheels on my Hyper Men's Cruiser. So I'm going to attempt to swap tires, rear pedal sprockets and rims between the two bikes. The only noticeable difference will be the Cranbrook rims are grey, mine are black. No biggy. Easily fixed if I wanted to.

ALSO I got a first hand look at the Schwinn Midway 29" bike. NICE. Looks very comfortable.

...must... ...resist....

It will be interesting which head you select. One thing to consider is that heads with large fins really help keep temps down on these little motors because they are air cooled, in spite of which one has the best compression.

 

[JerryAssburger]

True. One head has 2 more fins but they are slightly shorter, overall. I have one of those infrared readers somewhere in my garage... it would be fun to take temps. ....still have quite a ways to go before its broken in.

 

[JerryAssburger]

Talking to myself, but maybe this info can help new people..... as of today, I have the bike in "debug mode", as I've only covered 20 miles on it, tops. Since the last entry, I scored a Scratch & Dent Huffy Cranbrook for $51 (which I swapped the rims for) and a new head gasket. So far, the head has been holding together, and today I did a two way high "speed" run at 6100 RPM or 32mph.... (verified by my Tiny-Tach). I'm pretty happy with it, considering its nowhere near broken in yet. (Admittedly, there was hardly any throttle left to go for!) 4500-5500 RPM seems to be the Sweet Spot. A guy on another forum named Jaguar has posted do-it-yourself balance instructions, and I'm half-tempted to try it.... AFTER it's got a couple tanks of gas through it!!
So... no mods and a 36T can get a fat guy to 30mph. Not bad.\

 

[TheNecromancer13]

Talking to myself, but maybe this info can help new people..... as of today, I have the bike in "debug mode", as I've only covered 20 miles on it, tops. Since the last entry, I scored a Scratch & Dent Huffy Cranbrook for $51 (which I swapped the rims for) and a new head gasket. So far, the head has been holding together, and today I did a two way high "speed" run at 6100 RPM or 32mph.... (verified by my Tiny-Tach). I'm pretty happy with it, considering its nowhere near broken in yet. (Admittedly, there was hardly any throttle left to go for!) 4500-5500 RPM seems to be the Sweet Spot. A guy on another forum named Jaguar has posted do-it-yourself balance instructions, and I'm half-tempted to try it.... AFTER it's got a couple tanks of gas through it!!
So... no mods and a 36T can get a fat guy to 30mph. Not bad.\

Jaguar... Suffice to say that you should take his advice with a grain of salt.

 

[JerryAssburger]

I kinda agree- not doubting Jaguar, but doubting the "One Cure Fits All" balancing of these motors, since there are so many variables involved. The generic motor I bought is probably WORLDS different than a motor someone else buys from a different seller... and then there's the Manufacture Date variables.... ( ! ) I guess I'm at no position to judge this motor yet until it's broken in.
TheNecromancer13, thanks for your input since The Beginning. I ended up getting a better Sprocket Mount, and absolutely swear by it. Since the evolution of these motors seems to follow the forums, (with a HUGE delay) maybe someday the Rag Joint will go away...!

 

[JerryAssburger]

A bit more progress.... I received my 2nd CDI, so I put the 24" High Tension wire on it and moved it to under the engine and it works great. Glad to know it'll fire through longer wire. I'm also working on my air-cleaner-silencer project, using an air-compressor filter I bought on ebay. I won't be able to try it until tomorrow, but I know a good deal of noise comes from the intake tract, so maybe this might be effective.
Otherwise, goodnight!

 

[JerryAssburger]

OKAY... I'm back. Don't bother with the air-cleaner for silence mod..... While it worked fine, there was little to no perceptible difference in sound.
I sanded down my stock squish head (doing the 400 grit on a mirror thing) and bolted the head up with a new gasket and... it STILL leaks! What a crappy casting it must be. Unless I order another head, it looks like the 13-fin domed head is going to be a keeper. The bike runs fine, hits 32mph, and only has MAYBE 25 miles on it- so at this point, I'll just keep breaking it in. In the meantime I finally got my front brake (YES!) and a few other goodies. I'm going to look into buying some 1/2"x1/8" metal from Home Depot and make better fender braces, too.

 

[Tyler6357]

You should sand the cylinder instead of the head if you want to decrease squish gap. However, if you are hitting 32mph the gasket must not be leaking very much.

 

[JerryAssburger]

True! To explain- the original head that came with the motor was an eleven-fin squish chamber that wouldn't seal, so as a backup, I ordered a domed 13-fin head which works fine. As a matter of fact, I sanded down the original head to try and "true it", and it STILL leaks. Since they're very close to the same cc volume, I'm not too worried about compression ratio, but I DID want to see if there were any benefits of the squish-gap head over the dome, all other things being equal. Pretty frustrating.
There are people that SWEAR by the squish-gap heads, but in the fine print, it's only relevant at much higher RPM than these (stock) engines are typically comfortable running at.I just wanted to settle the argument for myself, but the original head won't cooperate!

 

[JerryAssburger]

Okay- yet another update. Bike just keeps getting faster and smoother. I finally ran my first gallon through it. Been too busy with other things to rack up serious miles on it. I did order THIS muffler for it, because it had a much longer head pipe, and WOW, did it make a difference. It's a little bit louder, but it feels like I added another cylinder onto it. I highly recommend it to anyone who wants a cheap upgrade.
http://www.ebay.com/itm/Stock-Chrom...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I'll keep checking in.

 

[JerryAssburger]

Just got a Runtong Carb- now the bike actually idles! It'll need leaner jets to mess with, but it's a big improvement over the NT.