So I managed to bend the header on this 2 piece expansion chamber exhaust made for a tomos moped so it would fit my QT-50. The result is indicated top speed went from 30mph to buried in the odometer somewhere. That and the bike sounds like a 2 stroke dirt bike now. This is awesome.
:)
Looks sharp!
YOU SHOULD MAKE THAT A YAMABOBBER LOLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
Or a yamburbo
You buried the odometer?! IT'S A F'N TIME MACHINE!
Hey Joe this is ryan from facebook. Glad you're happy. Joe means the needle went past the mph scale into the odometer. Just another tip, you should overengineer the mounting bracket like a mofo. Vibrations, bumps and potholes kill pipes that hang. Once I swapped from the mj50 2 speed to the new lc50 2 speed engine I lost my right side swing arm mounts on the engine case so the arm I'd usually use to mount extra brackets to was lost. I used the the part that connects to the axle to bracket the pipe to in the rear. Works really well but any deviation in axle straightness will send vibrations into the pipe so I had to use a dial indicator, propane torch and a hammer to ever so slightly get it perfect. The longer axle is from the mj or the pw rears, the bearing and bracket dealio is from a pw.
check it.
Wow ryan, I never would have thought to put another mounting point right on the rear axle. good idea. I used a pretty beefy piece of steel to get it connected to one of the original mount points. but through the axle with a longer bolt seems like a good idea.
Can I see some closer pictures of those BMX pegs. I think I understand how you said you fashioned that but I want to see closer.
Also, what kind of forks are you running? Any way to swap a disc brake front end and better forks onto this thing on the cheap.
Last question, what kind of tires are you running?
i put a puch boss on mine, but i attached it to shaft drive, since the engine moves with the shaft drive i figured why not? its hitting about 36 gps'd
"shaft drive"
?
"shaft"
Who's the black private dick
That's a sex machine to all the chicks?
SHAFT!
Ya damn right!
Who is the man that would risk his neck
For his brother man?
SHAFT!
Can you dig it?
Who's the cat that won't cop out
When there's danger all about?
SHAFT!
Right On!
They say this cat Shaft is a bad mother
SHUT YOUR MOUTH!
I'm talkin' 'bout Shaft.
THEN WE CAN DIG IT!
He's a complicated man
But no one understands him but his woman
JOHN SHAFT!
it is always funny!
ill post up later the answers when i got time.
Mine sounds like a 2 stroke dirt bike with stock exhaust, but it has the pod filter like yours and boysen reed block in it, wish I could say I built it, but alas got her that way, rapps off nice! Not obnoxious loud but not silent like they are stock, when /if I get the electrical issues settled on this bike, I' am dreaming of a gemco pipe....
^http://www.mopedarmy.com/wiki/Category:Performance_Tuning
after you read everything under required reading then think about what you want to dump $180 on. I'd put it towards building a pipe and spend the other $160 on other stuff.
Joe. The tires http://www.partsforscooters.com/154-62_14_Tire?sc=2&category=326 I think I got both of them together for $35 including shipping. super cheap and they seem very beefy for a lot of years of use. I've been considering 16" rims for a long time and now more so. Apparently you can run bmx tires on 16" rims and my thought is since bmx tires are so thin they'll conform to the road surface for running around the go kart track. Probably not too safe for on the streets but 65mph downhill bicycles don't use special tires. idk.
The pegs. 
that's before I drilled the holes through the pegs for a little extra zazz and grip.
The forks are from a 80cc or 125cc dirtbike idk. The main point here is that any fork you choose wont fit as the bearings and stem will be different. What I had to do was cut out the original stem from the 80cc forks and cut a stem out of a set of old qt forks. I then made it a press fit and just for a little extra travel because my front end sits so low(gonna change once I get my frame done up) I welded the qt stem into the bottom triple of the 80cc fork upside down. It helps to have a spare frame to build it up on before having to strip down the daily to put them on.
Oh and I shimmed the OD of the bearings so I could use the 80cc wheel bearings in the qt hub. I should of just measured and ordered some online but they're working fine so far. I need to have a spacer machined up to bolt the disc to but recently I've been elbow deep into building bikes for other people, I'll show you pictures of this ground up moby build I'm doing for a friend that gave me carte banche.
Here's something to get you excited about a velocity stack. Easily the biggest all over mph gain.
meant to say hp gain.
I GPSed it today. I'd say 36mph is the average, was probably doing 28mph before with the open air filter but stock exhaust. On some flats I actually hit 38mph but I think I had a tail wind. I also got down a hill at 40 and once I hit the flat again it held it.
It's worth mentioning that I am 6'3" and 250lbs. I'm pretty happy with the results and would like to try taller gearing, a velocity stack and a bigger jet. Also those BMX pegs.
Ryan, on the pegs, you just used the frame bolt and nut to hold them in? That is what it looks like and it seems that would work well.
That fork set up is pretty sweet but I was really hoping there was something out there that would drop right into the current steering stem with out all of the fabrication. That might be a next year project. It seems to me it would make sense to find a front end with disc brakes already included, wheel and all if possible if I'm going to go to that much trouble to get it to fit.
Either way, I appreciate all the help. This bike is way too much fun in a different way than my track bike and ducati. I love that everything is so cheap for it too.
the pegs are just like you said but I had to grind the bottoms to clear the case so the ends of the pegs closest to the frame are shaped like D's. I welded the bolt into one peg. This way the pegs don't scrape going around corners but eventually after other stuff in the works the pegs will be moved to a more sportbike-ish location. It's been said that the crf50 forks or some pitbike forks like that are a direct fit but just a slight difference in bearing size means that the qt's bearing cups wont be ideal. Also you can get them with a 14" front rim, caliper and disk. There are pictures on this site about that. Another thing is that the crf rim may be a lot wider but If you get the sting rear end then you can offset the entire engine to the left and keep the rear tire and hub center while running a really wide rear tire. This is on my to do list. I'd say since you're such a big guy that I'd keep the lower speed rear end. I'm considering going back my self as I think it's better to pull more power out of these engines by tuning for high rpms rather than using grunt. IDK but if you want a pw rear I may trade you mine for you're stock qt rear.
Peugeot forks bolt right on. I was able to reuse the bearing cups. I had extra bearings in case I dropped one, but most good bicycle shops will have them. Just bring one in for an example. You can find forks for the peugeot that have disc brakes already set up on 1997. I think they are like $399 or something. Gl.
I'm looking at a set of pug forks right now and the thing i find fault in is that you want the top of the fork slides to be level(or just slightly above in the case of a fork with a fork brace) with the top of the tire and since the pug uses 16"s or 17"s(and still the slides stick above those) you wont be able to get the maximum travel with the least amount of height(qt necks sit low). This means to get the same amount of travel as the stock qt forks you'll have to run the forks much longer which will change your rake, trail and other stuff. The other big thing is the top triple isn't a clamp style meaning you'll be stuck running really long forks. Though what I did to make the top triple a clamp style for my friends pug was to use a spare bottom triple that had to be cut up and shaved. But that still doesn't help the slide height problem. Lets see a pic of them on your qt, hopped up.
found it
see what I mean
Those are adjustable EBR forks. I can still drop them another inch or more and still have the full travel of the forks. In the other thread I talked about that I am raising the rear of the qt to correct some telemetry and I am going to lace our hubs into larger rims (anyone have a phil wood spoke cutter?). I don't mind the rake. I wasn't going to say anything until my build was done and then I wouldn't have to worry about any of these questions, but here we are.
These are m(n)opeds and if you aren't having to hack something apart to make it work then you aren't having any fun. A buddy hooked me up with these forks, so I went with them. I'll keep the "Peugeot forks are a direct swap" talk down to other qt owners who aren't planning do go to the extremes that I am.
well since we are on the topic. Can I go a little more crazy and find some USD forks that will work.
Also, what kind of things can I do with the rear shock to accommodate my big ass.
I noticed a lot of stuff on 1977moped.com but don't know what fits and what doesn't.
BTW ryan, I think I'm gonna order a set of those tires and see what I can do with some BMX pegs. Front end, might be a winter project.
Oh, also. With the pw gearing. how much top end speed will it add. How much slower take off will it be? Just curious ballpark. As much as I'd love better acceleration ultimately I just want to be able to cruise with in town traffic, which it already does much more easily.
There have been mixed feelings on the slow take off with the addition of pw gears. Some say that can't notice others say they can. I think that noob or someone posted some good numbers talking to the percentage of gain by changing the gear ratio. Search around for those or he might have them on hand.
Some guys mounted another swing arm on the other side of the wheel and put another spare qt shock on that side. You can replace the single shock on the qt, but what you need to look out for is a shock that has an a-frame linkage. Needs to have eyelit top and a-frame bottom. But that isn't necessary if you can fab up a new bottom linkage that would allow you to go eyelit to eyelit. Noobster made a shock extension that might work. Another thing to think about when replacing is that the shock is close the wheel and a new shock might rub or worse.
Has anyone ever fitted a tachometer to these motors. It seems what would really be nice is to see if you could still pull up to the same RPM with the PW gears.
dedic has, i believe. he has a secksay clear flywheel cover too. check his epic kit thread in the performance section.
Want to post in this forum? We'd love to have you join the discussion, but first: