think I'm screwed  By  rickwagner (Read 3,096 times)

I'm almost positive your rings are dead....Oil problems--->decreased performance----->Exhaust smoke-----> No start......



If your going in, miles well replace with upgraded parts


Around $50-60$ for bigger better parts (You have to take off the old anyway right?)

Or spend $10 bucks for some rings, do the SAME amount of work as you would installing a bbk but no performance gain.



Also, chances are if you ran close to out of oil, or had to use old oil, over heated, ect, the cylinder is more than likely damaged slightly and the new rings won't seal properly and burn a little oil. No noticeable performance loss, just keeping WEEKLY tabs on oil or sooner if you ride alot.



Oil blows out of the breather tube when worn piston ring/cylinder let compression into the crankcase, thus building up extreme amounts of pressure. Where does the pressure go? Breather tube.

If there were no crankcase ventilation you would have herd and or seen something blow while riding along with all of your oil.

A normal functioning gy6 will vent out "vapors" of oil along with air. If a lot of oil come out its because its being pushed out.

I ride hard and abused my engine so I get a "mist" Indicating mild blow-by.

When I rebuild it'll will go back to a vapor.

Your problem could also be your head gasket, but that's a Slim to nothing chance. I've herd plenty of stories about blown rings. 0 about a blown gy6 Head gasket


Its not as scary as it seems Just study this guide and keep it at hand if you choose to repair yourself.

ebay.globaldc.com/scooterparts/borekits/100ccGY6/install/bbk.html

You don't have to remove the whole engine like it shows. (I've done two bikes fine with it in) But you will have to take off a lot of the body.


Welcome to the forum! A year ago I started off in your shoes too.

I agree that if you are going to replace the rings on a 50cc, you may as well do a BBK. You are doing the same amount of work either way since the same parts have to be removed, serviced, and re-installed, but you get so much more performance!

I would go with the BBK if i had the money, right now it's all about getting the thing to run so I can make money. The only issue lies with the fact that my scooter doesn't run the 39mm piston. It runs the 44mm piston. The website testedscooterparts.com however does not have that kind of piston. Lucky for me, and anybody else trying to replace stock parts, I found a website that has all the 139qmb parts in stock. I will be going to the BBK kit eventually, but for now I just want my trike to get me to work..lol. Here is the website for the stock parts.

www.scrappydogscooters.com/

I ordered my crankcase from them and paid for the 2 day shipping and got it exactly when I was told I would have it. BUT the only problem is when you order and you need it faster than 5-7 biz days, you need to call them and they can ship things 2 days for a fairly hefty addition, but when you need the part, you need the part.

Also, the piston was black around the area between the wrist pin and the rings, and one of the ring seperators between the two top rings literally broke off the piston. Thankfully it did no scar up the cylinder so all should be well with a new piston kit.

One last thing, what is the proper spark plug gap? The manual I have says .6 but thats 6x bigger than your average gapper goes, so obviously is wrong. Its a crap chinese manual and they must run chinese metrics or something..lol...I would assume manybe .06 but I would like to know what other people have gapped theirs to since obviously these manuals I paid for are crap for the most part.

That once is to big I think.... mine is a 44mm piston

Ok but...here is the quandary you are in..and will still be in. If it is a TaoTao 44mm 63cc engine..they come jetted WAY to lean. So unless you upjet you are just going to burn up your new piston and rings. in short order anyway. So you may as well make in an 80cc at right about the price you will pay for a piston and ring kit that most likely won't last but a few weeks. Either way you go..you WILL need to upjet. Here is a link to a big bore kit at a give away price... www.ebay.com/itm/Big-Bore-Kit-GY6-50cc-to-80cc-Scooter-Moped-139-QMB-139QMB-Cylinder-Piston-NEW-/221216900660?pt=Motors_ATV_Parts_Accessories&hash=item33818e0634&vxp=mtr

www.ebay.com/itm/Piston-rings-set-fit-Chinese-Scooter-Moped-GY6-engine-49-50-60cc-OD-44mm-piston-/130936341804?pt=Other_Vehicle_Parts&hash=item1e7c6a052c&vxp=mtr here you go bud

1. How would I tell if it is a TaoTao engine? And why would it be a 63cc if it was sold as a 50cc?

2. This # carb jet, where will it go? Is it a high jet or a low jet in the float bowl area?

3. I used ether to start on occasion, plus I always ride hard. I have to ride 20 miles to get to work in the morning and back at night.

4. Let's say I go with the kit carasdad has posted(mostly cause it is dirt cheap) what would I have to do if anything to this beast to make full use of the upgrade.

5. On my carb there are no adjustments that can be made, outside of the idle. No fuel air ratio screw on it. So it seems jets would be the only thing I could do to it unless I buy an aftermarket carb. Which I can't afford right now.

6. Let's say I was going to break this thing in the right way, how would I go about doing that? The only place I would REALLY have to ride this thing in hard at is the two mile stretch of road between my neighborhood and the back roads I take to get to work(mostly because of traffic) and then only in the afternoons, because I leave at 5am and there's no traffic in the morn.