2009 Peace Sports 50

[cwazywazy]

Hi all. New member, first post, etc. I bought this Peace Sports 50 off Craigslist for about $300 back around August. Generic Chinese 50cc GY6 engine. First off I removed all the body panels to paint it black (It was bright yellow. Can't have that..) and decided that I liked it better without the body panels and that I'd be going for a more of a skeleton look. I replaced the carb shortly after I got it since the stock one was sealed up and had some issues that I couldn't be bothered to figure out when a new and better one was so cheap. I cut out the front of the airbox (Gave it a nice deep tone at WOT) and cut around the tiny hole at the back of the muffler which freed up the airflow a bit and made it sound better. The latest thing I've done is replace the big ugly brake light cluster with a small LED one off eBay. Wired it up and it works great. This was just the start of replacing all the lights with LEDs. I plan on removing the entire dashboard (Neither of the gauges work anyway. The gas float is stuck at the bottom of the tank due to the foam disintegrating and the hub for the speedometer on the front axle just doesn't spin the cable. Because of this I don't even know how many miles are on the thing. I just know that it's at least 450. ) and getting new brake levers/buttons since currently the buttons are integrated with the dash and my rear brake lever is broken off at the end due to a PO (I'm the 3rd owner of this magnificent machine) falling off at some point. I'll get small LED strips for blinkers and a pair of small 20w Cree motorcycle headlights. I have everything picked out.  I also plan on painting the wheels black, balancing said wheels, (Wheel weights in the mail) trimming the floorboard/battery holder/thing and putting it back in, etc.

Now for the problems so far: I bought some 5g sliders to try putting into the stock variator. Cannot get the nut off. I soaked it in liquid wrench and got the best grip I could on the teeth and I still couldn't keep it still well enough to break it free. Next step is an impact I think. Also before I replaced the carb it had some bad hard start issues which drained the battery and wouldn't start until I hit the kick starter as fast as I could. As a result, the CVT cover is broken. I tried JB welding it but that broke too, and recently a corner of the cover broke off when I removed it. I've given up on trying to fix it and I'll replace it. Sometime. If I feel like it.

Last week I ordered one of those cheap 100cc BBKs off Amazon. Amazingly, it still hasn't shipped. When I get it I plan on porting and polishing the head, lapping the valves, all that jazz. Hopefully by then I'll have bought a impact wrench from a pawn shop or something and gotten the variator off to replace the rollers.

ANYWAY, pics:



The night I brought this magnificent beast (Named Mr Scootson) home.






(Don't have a pic with the new rear light cluster ATM.)



My professional tuning JDM billet aluminum cold air intake.



Let me know what you guys think.

[spaz12]

Welcome to the forum!




Nice introductory with lot's of info.  

[90GTVert]

Great first post! An impact should take care of the variator nut. Just be careful putting it back on. If you use an impact you should use a torque stick or you risk damaging the threads. ANother alternative is to buy or come up with a holding tool.

49ccscoot.proboards.com/thread/527/removing-variator-cltuch-impact-wrench

Did you tune the carb after the exhaust and airbox mods? It seems to run well, so I'm guessing you did.

[cwazywazy]

Dec 9, 2015 9:48:16 GMT -5 90GTVert said:

Great first post! An impact should take care of the variator nut. Just be careful putting it back on. If you use an impact you should use a torque stick or you risk damaging the threads. ANother alternative is to buy or come up with a holding tool.

49ccscoot.proboards.com/thread/527/removing-variator-cltuch-impact-wrench

Did you tune the carb after the exhaust and airbox mods? It seems to run well, so I'm guessing you did.

I did tune it, it's not perfect but at least it isn't bogging out or anything. I'll be doing a finer tune after the BBK and all.

[cwazywazy]

Installed the BBK after porting/polishing and lapping the valves. Seems to work okay so far. Doesn't idle and runs lean under throttle. Did a test run at night which was fun with the 25w stock bulb.. On said run I couldn't resist going WOT and it pulls good. First thing tomorrow is to change the oil.

EDIT: Forgot to say that my intake and exhaust valves seem to be exactly the same even though one of the seats is a bit bigger than the valve.. These are the 64mm valve stems BTW.









(I still haven't washed the engine and stuff, okay?)

@90gtvert please shed some of your glorious knowledge on me. 

[90GTVert]

Sounds like the next thing to do after the oil change is to gather up your jets, install a larger main, and start working on a thorough carburetor tune : www.49ccscoot.com/faq/carbtune.html

Seems odd that the intake and exhaust valves would be the same. Pretty much any engine should benefit from making the exhaust valve a bit smaller and leaving room for a larger intake valve. Taida has certainly worked with these engines a lot more than I have though. I wouldn't expect a company with their reputation to send out something that won't work well.

[cwazywazy]

Dec 11, 2015 8:15:07 GMT -5 90GTVert said:

Sounds like the next thing to do after the oil change is to gather up your jets, install a larger main, and start working on a thorough carburetor tune : www.49ccscoot.com/faq/carbtune.html

Seems odd that the intake and exhaust valves would be the same. Pretty much any engine should benefit from making the exhaust valve a bit smaller and leaving room for a larger intake valve. Taida has certainly worked with these engines a lot more than I have though. I wouldn't expect a company with their reputation to send out something that won't work well.

I mean, it works and it seals well but I compared the valves and they seem to be the exact same size even though the intake has a slightly bigger seat. Could I just buy a set of valves that are the right size or even just swap over the old ones from the 50cc head?

[90GTVert]

The seat and the valve need to be precisely matched. You'd have to have the seat machined or replaced to accept a larger valve. I don't think it would be worth it. Just from what I can see in the pic, it's the recess in the head that's machined out more around the intake.

[cwazywazy]

Dec 11, 2015 10:32:47 GMT -5 90GTVert said:

The seat and the valve need to be precisely matched. You'd have to have the seat machined or replaced to accept a larger valve. I don't think it would be worth it. Just from what I can see in the pic, it's the recess in the head that's machined out more around the intake.

Yeah, so I'll just leave it as it is? Maybe a big valve head might benefit me in the future?

[90GTVert]

I guess I got mixed up after reading another member's post. For some reason I thought this was Taida. I read back and see that I'm wrong. Regardless, it's alright as is if it's running well.

[cwazywazy]

Painted a couple things.

[cwazywazy]

Would taking out the base gasket and replacing it with some sort of sealant (I have some of that silicone gasket stuff) to raise the compression be a good idea? Or would it just start hitting the valves?

[90GTVert]

You would need to check clearances to find out if it's safe to remove the base gasket. It would be a good idea to know your compression ratio or cranking compression (compression test) before getting too deep into this.

You need to put some modeling clay across the top of the piston. It's best to apply oil or some type of lube to each side so the clay doesn't stick so bad after the test. Assemble the top end and set valve lash. Turn the engine over two full revolutions (1 revolution of the cam). Remove the head. You should be able to immediately see if the clay has been broken through, indicating the valves are hitting the piston. Even if not, you need to do farther checks. I cut the clay in half across the centers of the valve indents with a razor, then measure the thinnest point. Be careful not to squish the clay when working with it.

You can see the squish clearance as well if you put the clay near the edge of the piston when you do it.

[cwazywazy]

Dec 14, 2015 8:15:57 GMT -5 90GTVert said:

You would need to check clearances to find out if it's safe to remove the base gasket. It would be a good idea to know your compression ratio or cranking compression (compression test) before getting too deep into this.

You need to put some modeling clay across the top of the piston. It's best to apply oil or some type of lube to each side so the clay doesn't stick so bad after the test. Assemble the top end and set valve lash. Turn the engine over two full revolutions (1 revolution of the cam). Remove the head. You should be able to immediately see if the clay has been broken through, indicating the valves are hitting the piston. Even if not, you need to do farther checks. I cut the clay in half across the centers of the valve indents with a razor, then measure the thinnest point. Be careful not to squish the clay when working with it.

You can see the squish clearance as well if you put the clay near the edge of the piston when you do it.

Just how thin is too thin? Has anyone done this or something similar before? Thanks.

[90GTVert]

Around 2-3% of stroke would be a minimum clearance. 41.4mm x 0.025 = 1.035mm or ~0.041". 0.035" is about the lowest I've heard, and that is for racing. For street 0.040-0.050" or about 1-1.3mm would be safer for minimums. The piston to head or squish clearance could be a bit tighter because there's more to worry about with moving valves, but not much. I still wouldn't aim for much less than 1mm there.