taotao cy50 t3

[dcalebro]

i bought a tao tao cy50 t3 about 3 weeks ago. no problems until now. i am having alot of blow by from the motor. what would cause that and how do i fix then problem

[noday]

what do you mean by "blow by" ?

smoke in exhaust ? smoke or oil from the valve cover nipple ?

these scoots came jetted very lean from the factory. if you have run it hard, at all, you may well have burned a valve or damaged the piston because of the lean jetting.

One of the first things I did was replace the carb and upjet.

any way, tell us more about the problem.

[Rebel]

Welcome to the forum.

Blow by in excess would be strange from a scooter that new. Do a compression test I think it should be no less than 125 psi but don't hold me to that number. Shot rings or valves can cause blow by, but is it running well? A bit of blow by is to be expected, then improve after the rings are seated in.

[dcalebro]

it started when i changed the break in oil to synthetic oil. started blowing a little oil in the air filter. so i changed back to regular motorcycle oil 10w40 and it is continuing to blow oil into air filter and carb. then it starts maing a fluttering out the exhaust pipe. that is when i know that oil is in the air filter. coming from valve cover nipple

[noday]

1-st you need to be sure you did not over fill the oil. too much oil in the crankcase will do this.

oil level should be at the mid mark on the dipstick, with dipstick pushed all the way in, not screwed down.

less than 750 ML of oil per change

you also need to determine if there is really blowby..... run the engine at idle with the hose to the valve cover nipple off.

if there is any smoke from the nipple, then you need a compression gauge with a 10mm adapter to check cylinder compression. see the link

www.dansmc.com/compression_test.htm

compression should be between 125 to 200 psi, with throttle open and engine warm.

sometimes the problem is a faulty valve in the emissions tubing & canister stuff.

it is hard to pinpoint an exact cause, at this point.

[dcalebro]

i have taken it to vespa of charlotte to have it checked and repaired. i am going to order a new carb for it so i can put it on when i get it back. what size jet should should i put in it. thanks

[Rebel]

Let us know what they do to it.

[dcalebro]

sure will . that is the only place in charlotte that i will let work on it. the only ones i trust

[noday]

good deal.

average stock jets for a 50cc are 34 idle and 78 main.

most replacement carbs come with those jet sizes.

however all scooters vary and you may need to up or down jet 1 or the other depending on how the scooter cranks, idles and runs.

for stock unmodified 50cc engines::::::

idle jet range 30 to 38

main jet range 74 to 85

any modification to engine air flow, intake or exhaust, probably will need a jet change to match an appropriate size jet to the new air flow

[dcalebro]

got my tao tao back todand it is running good. vespa done a service on it and checked it out and could not fine anything wrong. the only thing that it could have been was me putting to much oil in it. that was causing the blow by according to their mechanic. my question is now can you run synthetic oil in it when the manual says do not us it. their mechanic said it was best to run it because of the heat the motor generated. is he right or wrong

[noday]

In general most folks run conventional oil during the engine breakin period... 800 to 1000 miles or so. and then switch to synthetic.

some scoots will always have a little blowby with synthetic.

as long as it remains a "little blowby" I would not worry about

[Rebel]

Yeah don't use the synthetic until it is broken in.

[tylerevans]

I recently bought a Cy50-T3 scooter as well. I purchased it about 2 weeks ago, i was riding it for about and hour and a half when it started to decrease in speed rapidly, thats when i pulled over and cut it off waited about 10 minutes and got on it and it worked fine, any ideas why it did that?

[Rebel]

Welcome,

Has it done that again? Did it smell like it was getting hot?

[tylerevans]

No it hasnt done it agian but everytime im done driving it it makes a clicking sound from my exsaust and its smells like something is burning, and my horn doesnt work enless im going atlest 20mph