the wiring is coming along nicely. i’m going to have a removable led tail/brake light, and a removable headlight, and the battery will sit under the crossbar near the seat (and of course will be removable FOR RACE!). all the wires run to a central “hub” above and slightly behind the engine. the wires will tuck away nicely when i have the lights removed so it’ll be sleek and pretty.
heres a picture of the hpi coil and 3-way switch (on – off – on with lights). the brake light will always function no matter what position the switch is in.
the cdi box is on the other side.
i just need to buy some more connectors tomorrow and run a few more wires, then the engine can be mounted.
after letting the jb weld dry i put the intake on the bike and attached the carb. the new carb is gigantic so its kind of a bitch to get installed, but i think this is going to be worth it.
Turn the key… Choke… Kick… Kick… VROOOOOM… started right up. Checked for air leaks: None. Awesome. I can tell i’m lean at idle because it dies if i take it off choke. As far as the main jet… on the 18 i was running a 115 main jet and i think i was just about right. the 24 has a 95 in it stock so i’m probably lean, but man when this thing opens up all 24 millimeters it sounds MEAN. I’m totally stoked.
next steps:
-figure out an air filter situation. space is limited because this carb is so huge. i dont think a regular air filter will fit so I’ll probably just use some pantyhose.
-the carb is leaking gas a bit so i need to figure out where that’s coming from and plug it up.
-i’ve got an oil leak from the transmission but i think i just need to make a new gasket for the transmission cover
-tune this bitch.
-RIDE THIS BITCH.
some pictures:
After seizing the AR80 a few times after putting the kit on it, and spending money on a bunch of jets for my VM18, the jetting was still lean in the needle. The shitty part about VM18s is that their needle isn’t adjustable. You have to buy an entire needle set if you want to adjust it. So AJ gave me his Mikuni VM24. It has an adjustable needle and takes the same jets at the VM18 (also the VM series will take dellorto jets). Not only is it easier to tune, but it’s HUGE too. EXTRA BLASTO SPEED TIME!
Tonight I went to the shop and fabbed up an intake for it. The old intake was for a clamp mount VM18 and had a rubber coating on the metal plate that clamped onto the carb. I torched the rubber off and was left with a clean plate. The inner diameter was around 28mm, so i had plenty of room to work with.
Since the VM24 is a flange mount i needed to weld on a plate for the carb to mount onto and then weld a tube (AJ also gave me a Boss header ID:24mm so i chopped that up for the tube) from the old manifold plate to the flange plate. Shay had an intake riser for a gila kit with a hole already in it that was 24mm. Perfect. I drilled some holes into the riser plate to match the flange on the carb and welded it all together.
Disclaimer: I am terrible at welding. There were a billion holes in the welds so I lathered some JB weld onto the welds and sealed it up. The manifold is currently drying and i’ll be able to put it back onto the bike tomorrow and see if everything works out like i planned.
I soft seized the AR80.
I was at the shop yesterday morning working on the tomos clutch and while some epoxy was drying, i decided to take out the AR for a short ride. The weather was nice. It was warm. why not? I made about a mile and ZINK!!! Soft seize. I’m pretty sure my main jet is just lean. I rode it back on choke and it was only too rich in the needle. So i’m hoping its just the main jet being lean. I did get to take a nice picture at least.
I’ll be ordering some more jets soon.
I got my pilot jets in the mail yesterday and last night i rejetted the carb. I went from a 25 pilot to a 40 pilot, and from a 62.5 main to a 92.5 main.
the throttle is crisp and responsive now. no lean spots. its perfect. i did an idle plug chop and it looked a bit rich, which is fine for break in. I didn’t get a chance to do any wide open plug chops because it was really cold and it was late last night when i got done. I’ll get some done next week.
I did take it out for a minute or two and it definitely felt more powerful, especially when i hit the powerband.
i need to take it out longer to see if regearing is necessary. i cant wait to see what kinds of speeds i’m gonna get outta this thing.
Last week tim and shay helped me fix that air leak. thanks guys.
my jets arrived and i dialed in the main, but was still getting some lean bog on the lower parts of the throttle. i didn’t even realize that there was another circuit in the carb and it does actually have a pilot circuit. so i had to order some larger pilot jets. they should be here by friday. i hope i dont find out i’ll need to order other needles as this carb does not have adjustable needle heights, only different needles with different tapers.
I found those studs at Beck’s Hardware in Cincinnati:
I made a gps mount. i used a piece of metal laying around the shop and bent it to fit on the old instrumentation mount. i welded it on and made it work for both holding the key and my gps mount.
looks pretty good i think. it’ll look better once i grind down the welds and paint it black too.
then i tackled taking the cylinder apart and fixing that air leak. i removed the exhaust and carb then took the cylinder off and cleaned all the stuck paper gasket off the surfaces with some steel wool. i then sprayed copper gasket sealant on the new base gasket and installed the cylinder. did the same for the head gasket and put the head on. when i was putting the exhaust back on i noticed a funky bend in the exhaust gasket, but thought nothing of it really. after everything was back together i was able to start the bike and noticed that it wouldnt die when i took it off choke. thats an improvement. i sprayed some carb cleaner around the base gasket but still had a leak where i had it before: transmission side.
coincidentally this is the exhaust side too. i think i might actually have an exhaust leak instead or in conjunction with the base leak. i did have to do some modifications to the exhaust to get it to work with the new cylinder, so that may have caused some problems. i tried to tighten the exhaust bolts down and broke one of the exhaust studs, which actually sucks pretty hard because they have two different size threads on either end of the bolts. one is a 10mm and the other is something like 12. i’m gonna have to figure something out to fix this problem. i ran out of carb cleaner too and it was getting late too so i left it at that.
so now i need a new exhaust bolt/nut and i need to isolate the exhaust when testing for leaks to find out if it’s the exhaust, base, or both that are leaking.
ok cdi and timing explanation. it’s kind of complicated and long, but here goes. back when i was bump starting it, i lost my spark. whether it was from the actual bump start and the jolting involved with that, or just vibrations from riding, i dont know, but the nut holding the flywheel came off. then one time when i tried to start it, it backfired and the spark was gone. i took the flywheel cover off and realized that the nut had fallen off, and the flywheel was spinning freely on the crankshaft = no spark = sheared woodruff key. so i took the flywheel off and realized i had sheared the woodruff key, which is really just a pin like on tomos crankshafts. not having a replacement handy, i eyeballed putting the flywheel back on. i tightened the nut down and found a mark on the flywheel that is supposed to line up with a little arrow on the case to indicate if your timing is right.
i got out the timing light and the two marks lined up perfectly with the strobe. i assumed all was kosher, put the flywheel cover on and rode off into the sunset. little did i realize at the time (in my early and seriously lacking timing skill and knowledge) that these marks would ALWAYS line up if i didnt change the position of the stator plate – even if i attach the flywheel 180* off. so in theory, if i put the flywheel on and line up the keyway in the flywheel on the OPPOSITE side of where the key would sit in the crankshaft (essentially 180* off on the crankshaft) the two marks on the flywheel and case would STILL line up at spark even though spark would be happening close to BDC. this is due to the sparking mechanism being independent of the crankshaft, and only depending on the position of the flywheel and stator plate.
i hope that makes sense.
so after i blew a hole in my piston, i realized my error. I checked the timing last night and it was set at about 3.8mm BTDC when stock is 2.3mm or 20 degrees. I set it to 2.3mm and she seems to like it there.
i fixed the timing properly, installed a new air filter, and got it to idle without the choke. checked for air leaks and found one at the base of the cylinder. i need to rip it apart and clean the surfaces a little better. i have a sneaking feeling that paper residue from the original gasket on this thing is causing the mating surfaces to be uneven and cause the leak. lets hope i dont break another ring when i put it back together or i’m really screwed.
i tried to find some jets at the local motorcycle shop but they didn’t have the sizes i needed so i ordered some online. i also ordered some new tires… the old ones have some dry rot and cracks. hopefully i’ll be able to ride this thing by the end of the week.