what did you do to your motorized bicycle today?

sounds more like a problem with keeping chain tension tight rather than a spoke problem - throwing a chain with stronger spokes might have just snapped the spoke anchors right off the hub
 
You're right. I have another wheel with almost the same exact dimensions (but a cassette) so I'm gonna swap some spokes over.

Gotta find a better way to tension the chain.
 
Today I had a little time to play so I got my kx pipe set up and ready to install on the new build... I used the header adapter Fred sells and just had to cut the pipe in one place to re clock one bend, then trim it to match up to the header adapter. I chose to braze the pieces back together since I've never had a braze fail on an exhaust and it takes less time than setting up the tig welder.
I still need to re clock the stinger so it points straight back, then I need to find and aquire a silencer then that part of the build will be done.
The bike is coming close to completion but I still need to take the jug back off and match port the header adapter, intake, and install the piston rings, the cdi still needs to be mounted under the engine, and all cables and wires routed neatly and trimmed if needed.

Here's the bike as it sits now.... finally starting to look close to finished as progress is very slow on this one....

5MCbOf.jpg
 
Well the spokes from my donor wheel were a bit longer but with shorter nipples, so removed all the spokes from the drive side on my broken wheel (all were bent or broken) and installed the ones from the donor wheel. When it came to tightening and truing I found that the spokes were a few mm too long, so I took them out, relaced the drive side 4x instead and used the longer nipples that were originally on the wheel.

This is a first for me... 4x on drive side and 3x on right side. Test fit my rag joint sprocket and no interference.

Tomorrow will reassemble the back end of the bike and get it going.
 
tgaydos said:
Dave where did you find that air filter adapter?
Click to expand...

The air filter adapter is from a Yamaha pw80, it slips right onto the 18mm mikuni carb I'm using here but won't fit the stock nt or speed carbs unless you make an adapter to fit this adapter... it'll fit on the mikuni vm18 perfectly like in my pic and it also fits the cns carb, and of course, the pw80 carb. I don't recommend using a cns carb on these due to how finicky they are to tune and they leak like crazy if you don't have the right intake...

The best carb for these engines is the NT or the NT Speed carb unless you're doing some more serious engine mods, then the mikuni vm18 becomes a good choice, and so are the Dellorto phbg 19 or 21mm carbs, these are a bit trickier to tune but will offer better acceleration and top speed. I was going 43mph on my mountain bike with a stock NT carb and 44 tooth rear sprocket so don't underestimate the stock carbs either... the larger carbs really help the acceleration once some porting is done and will allow for more top speed, just switching from an NT to an NT speed carb will give you another mph or 2 if you got decent porting and a good exhaust...
 
mapbike said:
Looks real nice dave..!
Click to expand...

Thanks Shan... I can't wait to get this one on the road and see what it can do... this engine is based on my mountain bike engine but has wider ports, the kx exhaust, and an 18mm Mikuni carb so it should be just as fast if not faster as well as having excellent acceleration since I'm using a 44 tooth rear sprocket on this one too... I'll be happy if it can do at least the same top speed but I really want this one to be able to accelerate even better than the mountain bike did, that one accelerated really nicely but I'm hoping this one will do even better....
 
Surprisingly that seat is comfortable but it's most likely going to end up switched out for a cloud 9 or similar, it's not too bad riding around the shop parking lot etc, but that can change once it's on the road and doing 40+ ... I got a few other seats in the stock room that I'll most likely swap out once it's running.
 
blue engine.jpg well i got this painted and assembled yesterday today finished the build and the guy took it before i got to take a pic of it finished but hey its gone LOL
 
Well it's pretty but I hope you masked off the intake and exhaust ports...
I know that feeling when more pics need to be taken but the customer rushes off before it can be done... it's happened to me at least twice on custom paint jobs I've done on motorcycles before... I got all the pics of the parts off the bike but before I could get to my friend's shop to take pics of the bike assembled it was assembled and delivered... and this guy didn't even take a pic of it after he put it all together...
It's a bummer but it happens...
 
i always wipe the ports down with lacquer thinner before assembly i have been doing the engines this was for a long time. the customers are always surprised by the prismatic paint it looks so cool in the sun light
 
seen folks do this and end up with paint on piston & cylinder walls

I have a broken muffler, dead spark plug and old intake that I always throw on when painting these (I also use a bit of tape over bolt threads too) - the broken muffler makes a nice handle to turn it with while painting too

might even have posted a pic here of piston with a painted spot in the shape of a port
 
Took the engine cover off to investigate the cause of some serious vibration above 3300rpm in my briggs motor. Found out the flywheel, though secured well to crankshaft, has something like .015 or .020" total play up and down. Guess this engine was worn more than I thought when I bought it used. I only put 500mi on it!!!

Thinking what to do, I see those shortblocks on ebay for $120 that I could transfer all the parts over to...
 
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heres the before and after pics of my x chamber and this is the paint its 46 a pint but you only need two thin coats and then bake it in your oven at 300 for half hour $_57.JPG

chamber.jpg

20150718_222351.jpg
 
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