Sport moped exhaust on 66cc (Build thread)

[FurryOnTheInside]

Indeed. A half link will sort it out.

BTW when the chain is excessively long (ie enough to fit (too tightly) with a full link removed or to best be used with a half link) the tensioner/idler/pulley needs to lift the chain too far, with too acute an angle around the pulley.
The acute angle (with chain wrapped around a lot of the the pulley) means the chain pulls very strongly on the pulley. Just exactly how pulleys are used to lift huge sacks etc.

At a more obtuse angle (less "wrap") the chain hardly puts any force on the pulley.

So the tensioner/idler thingy will behave much better with the half link used.
Or you can use multiple pulleys to reduce the angle at each of them.

 

[Vikingimike01]

But buying a new sprocket is expensive

Anyways, I have to install the engine to my other bicycle frame, the 28" cruiser, because this one had the back shifter wreck itself, and now can't put chain on it.

 

[FurryOnTheInside]

But buying a new sprocket is expensive

Anyways, I have to install the engine to my other bicycle frame, the 28" cruiser, because this one had the back shifter wreck itself, and now can't put chain on it.

You don't need a new sprocket, and I'm doubtful you'll find many that have only 1 more tooth. How many teeth does the rear sprocket have, just out of curiosity?
You just need a "half link". Take out one full link, put in the half link. It's the easiest thing.
I have to recommend a homemade tensioner anyway, the kit one sucks.

 

[Frogslayer]

A table vice can make easy work of a chain but a chain press is really what's made to do the job and they can be had for 13 to 20 dollars shipped on Am a zon

 

[Vikingimike01]

Ahh. I see. I have a 44 tooth rear sprocket.

I'll buy a chain breaker next tuesday.

 

[dparenti13]

Any updates? Curious to hear how it rides..

 

[Vikingimike01]

Yeah, nothing yet. It's very cold and rainy here, so I didn't even really get started. I am however going to update this thread as I do things. Pretty occcupied with school now too.

 

[Vikingimike01]

Hello guys, very sad thing. Still nothing.

I took the whole thing apart, and cleaning it. I got the exhaust pipe cut to shape, no material removed/added just had to cut off some turny parts and weld them on at a different angle. It's not welded yet though. And I don't want to do it with a stick welder. It leaves all kinds of holes in the weld.

The stock NT carb I have has bended somehow. The part that connects to the float bowl, where the hole is for the screw, under the idle screw. It's badly bent. Like visibly. Not sure what to do. What's the carb specs? The hole the air goes trough and then eventually the fuel mix. It's like 15 right? I was thinking of getting a bit bigger carb like a 16 one, or something like a mikuni 18. But that would be too big. So I need a smaller one.

When adjusting the clutch cable, where the cable goes into the rod, over the small sprocket, the screw that holds the cable broke. So I can't remove/adjust that anymore.

I still couldn't get a chain breaker, so yeah. I need to save up for it. I had some more important things to pay for sadly, so yeah.

I'll look into the half link on ebay, for a 415 chain. And I was thinking of making a homemade tensioner with springs that attach to the frame of the bike. I have some very strong springs that came off of a hammock. Maybe too strong, but I do have one a little weaker.

I have started workig on the bike again, but I need to clean the fuel tank, and also I'll be able to reconnect the back brakes soon, because I trued the wheels. It was very rainy the last couple of months here, and still kinda is. So not much time, like 1-2 days out of a week to work on the bike. But I have exams as well right now, so yeah.

Sorry for this long novel, just trying to keep you guys updated on what's going on. I'm not dead, nor have I abandoned this project. I did want to sell my engines at one point, but I said, no. I had it for too long. I loved it. I still love it. Just very frustrated with all the fixing that needs to be done! I'm getting loctite for the screws...

 

[Spare_Parts]

I know what it's like to not have time or money. Been raining more than usual here. Hope it all comes together for you and good luck on your exams.

 

[JerboaJohn]

I measured a stock NT I have laying around and it's barely 15mm.
here too, once it stopped being so cold, it got rainy and windy. 1 gal of gas now it's 3 weeks old just sitting. might pour it in my car