what did you do to your motorized bicycle today?

[DRBS]

I have looked at a few different heads there basically the same. There are a ton of the ignition boxes some work better than the others I really like the one I bought last its a no name one and it has better mid-high rpm range my brother made me one last month and it works great

 

[mapbike]

I've been considering the jake's Diamond head for my next build too since it has the different combustion chamber design to see how that works out. Another one I'm keeping a close eye on is VMB's Shark head he's still designing and perfecting at the moment.
I just picked up a Super Rat bottom end from BGF Motors on ebay last night that I'll do my next build on. I know these have ignition issues but I got a few ideas to hopefully work around that issue, and now that I can get those ignitions fairly easily I'll take the risk. First thing I'll need to do with it is check the geometry and change out all the bearings for the good stuff. I'll also check, true, and balance the crank while I got it apart since it could just as easily be engine vibes that's killing the CDI units in these as well as the heat with not enough opening in the covers to let it escape out quick enough. My other thoughts here are that other magnetos might work better with the type of rotor this engine uses.... We'll soon find out.
I also saw that the same seller has the jugs with the straight intakes installed on them so I bought one of his to see if it has the bigger flat transfers, if so that'll be great, but if not, I got other sources for these jugs. The Super Rat bottom ends he sells also come with a piston installed so that'll take the initial guess work out of piston selection too.

I'm hoping I can get one of these to work reliably because these will make for a very clean looking install on future builds.

I think you'll like the design of the diamond head Dave, Im not gonna claim it to do a better job than the Fred head or similar, but a.016 gasket used on each one will cleary raise compressjon more if the Jakes diamond head is on that same engine because of how the squish band area will actually be down in the hole just a little, the lack of me considering this fact is how I ended up with a tight squish than I was aiming for on the newest "Taffy" build, I was looking for twice the squish that I ended up with, so Its possible that I will need add a thin base gasket to what I already have or make me a thicker head gasket or just make a thin one from some of the 8mil aluminum I have, Im concerned about not having but slightly over 1/4 of a mm squish clearance, compression is gonna be through the roof with that setup and may just be way to high, but of course I have to try it first to see how it acts.

Im a little concerned about continued gasket compression as the engine runs a while, I sure dont want it getting to the point that the piston starts to strike the head.


Ive looked at those SR engine BGF has listed, if the engine atually is a SR it will be 40mm stroke and use the low pin piston, best wishes on the build, Im looking forward to hearing about it and how well it runs.

 

[Davezilla]

So on the Diamond head the combustion chamber protrudes into the bore? that'll be nice since it can save time shaving the top of the jug down for sure. I'd use the copper gaskets from Juice to prevent gasket compression and get the squish clearance just above 1/4mm just to be sure the piston can't hit the head. the .016" thick gaskets he sells come out to about 0.4mm so by adding one of these at the base or at the head you'll end up with about a .65mm squish clearance which would put the compression ratio at a more reasonable level and prevent the piston from hitting after the engine warms up etc... As long as you keep the squish below 1mm you'll be in the acceptable range where it can still work to prevent detonation really well.

I know on my current running engine it has a 0.75mm squish clearance and the compression ratio came out to 12.7:1 so I run 93 octane premium and have no issues with detonation, of course, that's the static compression ratio and the actual is measured from the top of the exhaust port up making the effective compression ratio closer to around 8:1 or so.

 

[bluegoatwoods]

Okay. Here's a better view of my handlebar choke adjuster.

I actually did not want to use that rather ugly greenish cable sheath. I've got plenty of black sheath on hand. But the green one was long enough for the job and I guess I didn't want to see it go to waste. Being a bit of a miser? I guess so.

But it also worked out well, in a way. In these pics there's now no doubt about which cable to pay attention to.


A home-made L bracket fastened to the seat tube forms the cable stop. Then loop the cable over and run it along the top tube up to the twist shifter on the left hand grip.



I took her out this morning when it was about 50 deg F or so. That's not all that cold. But it's enough that the engine wants some choke. The results were very good. I was able to 'feather' the choke on and off with a good deal of accuracy.

No more 'too much' or 'too little'. Yay!

By the way, my pics 'zoom' quite well. You can get a close look at it.

 

[bluegoatwoods]

Maybe I ought to add one word of caution:

You can not mount the cable out at the end of the choke lever. Out there where you find the little 'nubs' for your fingers.

The reason for this is that your shifter does not have enough 'throw' to get that choke fully closed. Or fully open, if you adjust things from the other end.

The cable must be mounted closer to the fulcrum. So this means that you need to fab up a little tab that you'll attach to the choke lever. Giving you a decent spot, closer to the axis to attach the cable.

But that's not hard. Mine only cost 25 cents.

 

[mapbike]

So on the Diamond head the combustion chamber protrudes into the bore? that'll be nice since it can save time shaving the top of the jug down for sure. I'd use the copper gaskets from Juice to prevent gasket compression and get the squish clearance just above 1/4mm just to be sure the piston can't hit the head. the .016" thick gaskets he sells come out to about 0.4mm so by adding one of these at the base or at the head you'll end up with about a .65mm squish clearance which would put the compression ratio at a more reasonable level and prevent the piston from hitting after the engine warms up etc... As long as you keep the squish below 1mm you'll be in the acceptable range where it can still work to prevent detonation really well.

I know on my current running engine it has a 0.75mm squish clearance and the compression ratio came out to 12.7:1 so I run 93 octane premium and have no issues with detonation, of course, that's the static compression ratio and the actual is measured from the top of the exhaust port up making the effective compression ratio closer to around 8:1 or so.

Yes with the right gasket that is thinner than a stock kit thickness gasket the outer edge of the squish band will be slightly down into the cylinder bore, the head gasket actually seats around the squish band rather than the edge of the combustion chamber sitting on the head gasket like it does with all the other stock and after market heads.

Not only could this increasing compression on an engine that hasn't had any deck material removed but its also going to help prevent blowing a head gasket possibly, of course if the head gets loose none of this will matter since it will leak no matter what, but the way Jake had them design this head it actually sorta interlocks with/in the cylinder bore when a thinner .016 etc... gasket is used, this also puts the combustion chamber perfectly centered over the bore since the outer edge of the combustion chamber closely fits inside the cylinder bore just slightly.

I'm using a stock thickness head gasket with mine since thats what i have on hand, i shaved the deck height for use with this thicker gasket, the next engine I build with the Jake head design will likely get a thinner gasket, next engine to get this head used on it will be one of my dax GT5 type engines.

I'm not trying to start a debate over which head is best or anything like that, and really this is kinda the wrong place to talk to much about it, but I do like the design of the Diamond head even though its big and tall compared to all the others, I am gonna go down to my local motorcycle shop and see if I can find a longer reach NGK plug for them, the E3 3.22 will work,but even as long as it is it could stand to be 1/8-3/16" longer reach to use all the threads in the head.

Once I find out which plug is the ideal length I'll post it in the correct location so others who may be interested in running one of these heads will know what plug they need to get for it.

 

[Panhead]

After seeing a photo of another bike with a velocity stack I decided to try the unrestricted route with my own ride & pulled the outside cover & filter. Rather amazed at the difference just this small change made. In the cool, damp spring air that baby wanted to run!
I've just ordered an angled intake from another of the members here, a man named Brad, & will soon be looking to replace the Ruixing carburetor with something a bit less temperamental.

 

[bluegoatwoods]

I had pretty much decided a week or so ago to convert my bike from multi-speed, derraileur type to single speed coaster brake type. Just for the simplicity of it. But since that means a fair amount of retro-fitting, I figured I'd wait until I had a good, solid few free days.

Then yesterday at about noon I walked on out to the bike, to run a short errand, and found a flat rear tire. So I figure I might as well go ahead and do the conversion if I have to pull that rear wheel anyway.

So it took me the rest of the afternoon to pull the rim brakes and clean up the cables and handlebars and install the new rear wheel. That wasn't really so bad. But I felt a bit crabby about it because I had other plans for the day. But...no big deal.

I got it all together as the supper hour was approaching. Took it out for a test run and toasted a wheel bearing. The one on the brake lever side of the wheel. That particular one seems to be a bit problematic; I've had trouble with those before.

So I replaced that bearing. I have one more as a backup. I'd better order some more. By that time the Sun had just about set.

So now it's morning and I'm waking up with a couple of cups of coffee. Then I go out and try to make sure that my bike is road-worthy. I've got a couple of hours before my work week starts. If I can't trust the bike, then it's a week of commuting by car. (Though I suppose my pedal bike could be ready without much trouble.) That's not the worst thing in the world. But I'd rather just have a working bike.

So wish me luck, eh?

 

[mapbike]

I had pretty much decided a week or so ago to convert my bike from multi-speed, derraileur type to single speed coaster brake type. Just for the simplicity of it. But since that means a fair amount of retro-fitting, I figured I'd wait until I had a good, solid few free days.

Then yesterday at about noon I walked on out to the bike, to run a short errand, and found a flat rear tire. So I figure I might as well go ahead and do the conversion if I have to pull that rear wheel anyway.

So it took me the rest of the afternoon to pull the rim brakes and clean up the cables and handlebars and install the new rear wheel. That wasn't really so bad. But I felt a bit crabby about it because I had other plans for the day. But...no big deal.

I got it all together as the supper hour was approaching. Took it out for a test run and toasted a wheel bearing. The one on the brake lever side of the wheel. That particular one seems to be a bit problematic; I've had trouble with those before.

So I replaced that bearing. I have one more as a backup. I'd better order some more. By that time the Sun had just about set.

So now it's morning and I'm waking up with a couple of cups of coffee. Then I go out and try to make sure that my bike is road-worthy. I've got a couple of hours before my work week starts. If I can't trust the bike, then it's a week of commuting by car. (Though I suppose my pedal bike could be ready without much trouble.) That's not the worst thing in the world. But I'd rather just have a working bike.

So wish me luck, eh?

Best wishes....bgw

Hope you got all the gremlins worked out of the motorbike.

having bearing trouble like that seems odd, but hey those thing happen.... I guess Ive been fortunate not to ever have an6 bearing issues with any of my bike wheels, coaster or multispeed, im sure eventually I will though.

I adjust my bearings welk and use a very good grease in them since I ride in such hot, dry, dusty conditions most all of the time, many of my rides are long and at a good clip with several miles on very dusty celiche roads before I even see pavement.

What brand of coaster hub are you running just out of curiousity?

 

[Panhead]

Today I fiddled with the Ruixing carburetor a bit while running the engine without a filter. Wound up with what I believe to be the gas/air screw set at a spot that seemed to make the engine happy. Then, I took it for a ride around the block - good thing that it has pedals & that I managed to adapt that one-piece crank to function with the 4 stroke engine. Still running when I rolled into the drive, but the plug was badly fouled when I pulled it. Out came the wire brush.
I am looking forward to delivery of my angled intake & a plain 2 stroke carb with a choice of jets.

 

[Agreen]

Searched for it some more. It was stolen Friday, March 27th.

My wife posted it on Facebook. 2 hours later someone took a picture of a kid riding it about 4 miles from my house. Been camping out there ever since, still nothing.

 

[bluegoatwoods]

It's a brand new Shimano CB-E110. This is the first time I've looked inside one of them. Nice stuff. It was greased well with some grey-ish grease that I didn't recognize. Since I took it apart and reassembled a few times, some of that grease has been lost. But no matter. I'll be taking it apart again to make sure all is well when my weekend comes.

After this morning's post I took the bike out for a very short ride right in my neighborhood. All seemed well. Wheel turned freely and brake worked properly. So then I took it uptown. Total might have been as much as two miles. All seemed well. So I decided that it was trustworthy to go to work.

I got there with no problems. I went a good deal more slowly than usual, just to be cautious. When I got to work I found that the bearings had more play in them than I was comfortable with. So I tightened them up.

On the way home I stopped at the grocery store. Picked up some canned goods as well as a bit of other stuff. The load went into my rear cargo duffel and into my front basket. I overdid it. It definitely felt like the tail wagging the dog.

I had to go, again, quite slowly and quite carefully. There's some rough ground on my commute. But everything held together. I think I came through okay.

I'll still want to 'zero in' the adjustment of that rear wheel and it's bearings come Sunday. But it feels as though it'll be okay until then as long as I keep an eye on it.

 

[Davezilla]

Well I got my first shipment from BGF Motor on ebay which was a jug and 2 chains... didn't mess with anything today but checked out the jug to find it has the cat eye transfers and the tinyest ports I've seen on a 66cc yet... but at least it came with a straight intake I can bore out and save for later...
I could open up the ports on this jug but I got plenty enough flat transfer jugs for making fast. I'll just save this one for mock ups or if a customer needs a new jug, but then I would at least port it before selling it to anyone.
I should be getting the super rat bottom end Monday so I'll pair it up with one of my ported flat transfer jugs then decide which head I want to use on it. Of course, this means I need to start looking for a bike to put this on but I'm never in a hurry here... I got a small bmx from a guy a few weeks ago for $10 but that's gonna take a lot of fab work before an engine will even fit in it. Would much rather do a cruiser or another mountainbike if I can find anreally cool one.

 

[DRBS]

yea I know what you mean I have bought parts and there not exactly what I wanted but will work with mods. im buying the carbide tips I need this weekend and going to start porting jugs and selling them. there are a lot of ppl calling me asking for the ported cylinders so I guess ill spend a few days porting!!! I think ill do 4 of them and one for ME LOL. im going to build MY BIKE THIS WEEK!!!!!! I have been building them for sale and keep selling the one I want cause someone wants one like mine so its break time from selling and time for me LOL

 

[Davezilla]

I get the same thing over here... everyone wants to buy my bike instead of me build them one, or they want my parts like the pipe I made or the Fred head etc...

For the cylinders tho, I do have a few sources for the better flat transfer jugs with much bigger ports... this just saves me a lot of time when porting. I got a few good sets of carbide burrs both for the dremel and for a regular size die grinder as well as sanding rolls for finishing and a few other toys to speed things up while staying accurate. I got one set of 10 carbide burrs off ebay for around $20 that can cut fast and another set that are 3" long for getting up into the transfer tunnels, these are all 1/8" diameter but different shaped and double ended so that 10 piece kit is the same as a 20 piece kit. These are also fine cutting so they're not really fast but they can get into just about any spot and can cut very accurately. I got this set off ebay as well... I can post the links if interested. Some other tools I got for porting are the harbor freight mini grinders these spin at 54000 rpm and need a good size compressor to use continuously, but a lot easier to handle in tight spots than the dremels. Then I got a pneumatic file that can cut nice flat areas quickly or I can use needle files in it when even more precision is needed.
by far the most useful tools I got are the carbide burr sets, they're quick, accurate, and can do just about any cutting task without the help.of the other tools.

 

[DRBS]

well I hope that I can fins a supplier of motors that can keep up with my sales!!!! LOL I sold 27 of these last year and looking to sell 35 this year I am going to build MY BIKE this weekend im going for top speed around 48MPH new and maybe 53-52 when broke in!!! my Schwinn admiral does 43 and my kent fixie goes 45 I should get this bike in the higher 40"s im porting a cly right now im doing a flow chart that Edelbrock uses for there carbs and fuel injection but lowering the size down to our sizes. my next idea is can we add fuel injection to these bikes????? ill let you all know. im going to Jegs to look at there test area on the 4/9/15 to figure out if these are worth building I told him I feel that I have been insulted and he should consider what he will be losing that Motorized Biking IS BECOMING THE NEXT HOT ROD IDEA EVER TO HIT THE PLANET !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

thank you
have a blessed day
don bovitz

 

[Blakenstein]

Here 's what I'm doin right now, new clutch came in today, and I'm gettin it on!!! Here are pics, with the old one also, those two springs that I added worked real good and are still on there, but as you can see, the pads are gone!! " Mc cready,..its gone!!!" anyway, the new clutch is heavy duty and kicks in at 2,650 rpms. It is American made, and fits on most motors that have 3 inch double shoe clutches. ( 76mm)

 

[curtisfox]

Here 's what I'm doin right now, new clutch came in today, and I'm gettin it on!!! Here are pics, with the old one also, those two springs that I added worked real good and are still on there, but as you can see, the pads are gone!! " Mc cready,..its gone!!!" anyway, the new clutch is heavy duty and kicks in at 2,650 rpms. It is American made, and fits on most motors that have 3 inch double shoe clutches. ( 76mm)

Were did you get it from?..............Curt

 

[Blakenstein]

Staton INc. Im very glad that I found them. I also bought 4 spare springs and two of them are 2120 rpms, just in case the 2650 are two high.

 

[GoreWound]

Today I maybe killed my bike...

cross your fingers for me folks, I'm going in.

*edit: Oh No!