Gy6 problems
 

Hello,

I am new here... but i have some serious problems, first, i bought:
- 72cc whole cylinder kit (with head - harder springs),
- A9 performance camshaft
- main jets (82-90)
- new air filter, engine oil, new spark,...

I have tried to install those things, but i realised the valve head (one spring) was allways stuck - bad valve spring... so no good...
-then i installed stock valve head.
-Then i was on timing.... the timing mark and cam marks was correct (at TDC)... but now that i installed new cam, i cannot allign the cam marks perfectly with the block. So i leaved it so, because i thinked, that if im wrong for 1 tooth, the scooter must work, and i can adjust it later, when i test it...
-then i cleaned the carb and changed the main jet with a 85.

until then, i cannot start the scooter... even if i suck on the vacuum hose, to fill the carb.. it dont works... i have air, i have a good spark-s,...

but for the fuel i am not so sure... because the spark is dry...
i noticed that if i touch at the carb air intake, it somehow, "trows" the fuel out.. not "sucks"....

Can this be the problem, and if, whats the problem... please correct me, my steps, what i did good and what wrong... correct me.. i want the scoot so, want to fix it...

tnx

Hi
Welcome aboard
Pleased to meet you
Ah i so wish that people would take it slow when modding their motorbikes
So many try to do too many modifications at once and when things go awry it makes it very difficult to track down the problem
I shall get back to you asap as im out and about right now it being the Memorial day weekend and attemp to help out
Im very sure others will reply as well
We shall get her running so take heart and dont panic
Take care and ride safely
Yours Hank

The FIRST thing you need to do is line up the timing marks. If you are off by "one tooth" you won't run at all, and if you do, you most likely will damage the valves/piston/camshaft ect.

The SECOND thing you need to to is check COMPRESSION with a COMPRESSION TESTER and read the PSI of pressure you have. You CANNOT tell if you have adequate compression by 'feel'.

But whats the thing, if i look that the piston is in TDC... thats the right spot to put the camshaft in place.... that...
when i put the chain on... it is the cam (read - markins) little right.. or if i try to fix it.. is little left... what could be the problem?

IF their a little out there is a possibly you are really 180 degrees off. Are you using the timing makes on the stator housing?

Yes i use the marks on magnet,... and yes, is the same, if i turn around 180 degree, is the same... but... i have this strange feeling the Chinese so called racing cam a9, is fault.....

because also when i tried to start the engine.. it was blowing air out in intake manifold.. not sucking (creating vacuum) so something is really wrong

If its blowing that means the intake valve is open during the up stroke or isnt closing fully. could there be something stuck in the valve seat? maybe a missing nut or bolt? To big to pass (A good thing) but small enough to keep the valve slightly open.

Or worse yet, a bent valve?

i will check.. tommorow ill get the new valve head with new valves... so im reporting in the new days...

and.. no no missing bolts or nuts... i hope not :)

I installed today the new head... and the same thing :(

http://www.scootdawg.net/<a href=htt...y7Dq/photo.jpghttp://shrani.si/f/3n/8t/2iu6c2PQ/photo.jpg

So correct me if im realy dumb and with stupid questions...:lmao:

the Cam must be aligned so, that the larger hole is up, correct?
The TDC is the top dead center of the cylinder, and where the cam must be aligned (or nearly) as in the picture?
The TDC is usually aligned to the magnet mark "T",....
The TDC, you can determine, by the feeling of the "resistance" in cylinder?


So what am i doing wrong? i simply cannot align the camshaft :ugh:

Timing chain might be off a tooth on the crankshaft.

I just notice that the chain isnt fully seated in the photo on the right side (Of the photo) could the chain be worn and stretched out? I do know that it should be fully seated all the way around the cam gear.

Did you replace the cam and NOT the chain? if so thats your issue, a worn out chain.

Use the A9 cam, set the cam and make sure the two holes are level with the top of the head even if they are slightly below the edge. If the hole towards the intake is slightly above tighten the head down to specs and put the chain tensioner in turn the engine not trying to crank it but by hand and see if it lines up. Verify that the piston comes up to the top of the deck or just below, you can feel the top of the piston while moving the crank in forward and reverse there will be a mm or more of space where the piston will not move as long as the holes come in to where they need to be it will run. I have seen flywheels off with the marks also.

That cam came out lined up it will go back in lined up just take your time and look at everything again.

Somehow i figured it out ... 2 days ago... just like nightriderrv said...

But i have a question...

is there somekind of a "limiter" for 4t to buy? did somewho this? because in our country is that law that 50cc scoots arent allowed to run faster that 45kmh...

If there were a "limiter" is super because i would use it with a switch.. when police stops me ;)

So the question are:

- hows about a limiter - is there any, link please ;)
- Which Clutch and torque spring should i buy, red 2k rpm?

the A9 camshaft uses a slightly longer chain. You need to replace the chain.

NO there is no "limiter" or "governor" on gy6 bikes, this is URBAN MYTH.