trouble starting my gy6 150cc help experts? By dencho1992 (Read 2,058 times)

[dencho1992]

Ok everyone so heres the deal. i have a 2008 150cc BMS v9 Evo its also known as the heritage and a Znen model... at least i think. anyway it has a qmj157 gy6 engine and its been sitting in a parking lot for lets say about 8 months to a year.
I recently crashed my car so now this chinese scoot is my only way of getting around... if i can get it running hah

Problems in the past. so the reason i stopped riding it was becouse the spark plug seriously blew out like i was riding at full throttle for a while and it just POPPED and stopped running i looked an saw that the spark plug was hanging out. walked it home with a sad face and brought it to the only mechanic in town that would work on it. 120 dollars later turns out all he did was put a new plug in.. it popped out on the way home and walked it home again.. parked it in the parking lot and never rode it again untill now.

So here what ive done so far. i ordered a new cylinder head from ebay with the valves already set. cuz u know i figured the stripped head wouldnt work so well. next i sswitched it out and set the valves to .005 since i guess before i set the valves wrong causing the pop in the head. this time i double checked and made sure i did it right. after i set the new head in i cleaned out the carb i took it out and cleaned every crevis with carb cleaner. checked all fuel lines and vaccum lines the petcock work i tested it by sucking on the vaccum line that runs from the petcock to the carb and little spurts came out of the petcock when ever i would stop sucking. is it supposed to be like that or is it supposed to be a constant flow (it would go as this. id suck nothing came out, id stop sucking then a bit of fuel came out.) i changed out the fuel filter and replaced my battery with a new one. replaced fuse and made sure i have a spark by placing the boot with plug against a ground a starting the scoot.

now i dont have a preasure gauge so what i did to check preasure was put my thumb on the spark hole and tried to start it no matter how hard i pushed it popped my thumb off. theres fuel going to the carb and i reset the mixture screw by turning it all the way in then 2 and half turns out. changed the engine oil and gear oil. hmm i notced my muffler had rust inside it i thought it might be clogged with rust so i ordered a new muffler now regretting it becouse i blew through it and it was not clogged at all.. great.. so yea the scoot tries to turn over but nothing gives just bwuah bwuah bwuah bwuah bwuah same thing... gets a little tiny faster when i open the throttle but nothing.. i thought it might be the auto choke so i took it off and pushed it in a couple times it went smoothly and its a newish bike i bought it about a year ago beginning of 2012 oh i also derestriced the airbox a long while back by rmoving some of the filter cover and leaving jsut one filter instead of 3.

i really hope its not a engine problem for i already pourd 400 so far into this ressurection.. if anyone has some ideas to what it might be please let me know

[justbuggin]

if you suck on the vac line and get no feul then you have your petcock hook up wrong or it is bad with no vac your petcock should cut the feul off and with vac you should have a steady flow of feul

[tvnacman]

pull the vac line off the tee crank and let it suck about 1/2oz of fuel . It should sputter or start if it starts connect the vac line quickly . If everything is good with the vac system and the carb it should run normally . I find the carbs that sit with gas in them more than a month sometimes need to be retired regardless of cleaning .

Your welcome to call I would be happy to help how ever I can .

John

[dencho1992]

Hi thanks for your reply I will record a video when I get home later today and post it up for you all to see. but when I suck on the line yea from the tline from the carb nothing comes out as I suck on it (nothing comes from the fuel like from the petcock to the carb) but until where I stop the vaccumm a little spurt comes out. and when I suck on it again or start the vaccum I guess nit does the same no gas comes out till I stop the vaccum is this normal or do u think that is the problem? I have a compression gauge tool coming in the mail itll be here later this week and I will post the psi results when I get them but I heard they were supposed to be over 100 psi or ideally like 150-175psi correct? I hope its just the petcock...
THANKS ALL AGAIN

[tvnacman]

pull the fuel line from the inlet to the fuel filter , suck on the vac line going to the petcock . Gas should be comming out at a good flow . Just be syre there in fuel in the tank . you could make a gravity feed to the carb just for test .

John

[dencho1992]

ok so it doesn't come at a flow it would if I was constantly sucking and not sucking like taking breathes at a certain interval but it should be coming out as I suck on it right? and how would I go about making a gravity fuel feed? what purpose does that have and would it be a long term solution? I have no problem replacing my petcock if that's the issue I just wanna be sure that that's the problem before I go about it.
ill post the video soon when iget home on how my petcock is operating via youtube.

[tvnacman]

steady suction on the line should get the fuel flowing . the gravity feed will confirm the fuel petcock problem .

John

[dencho1992]

thanks john how do I go about setting up a gravity feed to verify the problem on the petcock so I just use a gas container with the hose going from it? like a funnel? wouldn't that over flow the carb? also is there any sure way to test if the problem is with the auto choke besides using a multimeter or replacing the choke totally? thanks again for your quick response

[tvnacman]

www.scooterworks.com/auxiliary-fuel-tank--2l---motion-pro-products-1909.php?page_id=193

[Alleyoop]

First I would check if you have Spark. Take a spare plug take the boot off the one on the motor and put the spare plug in the boot. HOLD the plug on the VALVE COVER OR MOTOR and crank it and see if it sparks. Checking for SPARK on the frame is NOT GOOD ENOUGH. It may spark on the frame BUT NOT on the MOTOR. Check the GROUND FROM THE MOTOR to the FRAME and make sure the WIRE has GOOD CONTACT on a clean metal part of the frame.

If SPARK is present holding it on the motor then we can move onto the FUEL tests.
CHECK FUEL DELIVERY:

Take the Carb Fuel hose off the Carb put it in a container and crank the motor over.

A. IF FUEL STREAMS OUT, fuel to the carb is good, Filter is not clogged and Petcock is working now

Re-connect the Fuel hose back onto the carb—GO TO CHECK CARB.

B. NO FUEL COMES OUT, take the Fuel Filter off and crank it again

a. If fuel comes out the Fuel Filter is Clogged.

b. If fuel does not come out –GO TO CHECK PETCOCK.



CHECK PETCOCK:

Take the Vacuum Line OFF going to the Petcock from near the carb and suck on the VACUUM LINE.

A. If fuel comes out you have a VACUUM PROBLEM.

B. If fuel does not come out you either have a bad petcock or a clog from the tank to the petcock.

Disconnect the fuel line going to the Petcock from the tank.

a. If fuel comes out the petcock is bad

b. If fuel does not come out either the hose from the tank is clogged or the tank outlet is clogged.



CHECK CARB:

First turn the Fuel Ratio Screw Clockwise until it stops and then turn it out Counter Clockwise 2 ½ turns

And try to start it.

A. If it does not want to start get a paper cup and put in about teaspoon of gas. Take the Vacuum hose off the Intake Manifold squeeze the paper cup and make a point and pour the little bit of gas straight into the Vacuum hose and connect the hose back onto the intake manifold. Now try to start it.

a. If it attempts to start or start and die now we know gas is not being sucked out from the carb bowl—GO TO CLEAN CARB.

b. If it does nothing time to check for Spark and Compression.





CLEAN CARB:

Take the Carb Bowl off and unscrew the PILOT JET and MAIN JET.

First clean out the Jets make sure you can see Daylight through them.

Then Spray into the holes the Jets came out of and clear out the passages.

When you do this spray will come out of different areas. When you spray into the pilot jet spray will come out by the front of the carb by the Butterfly. When you spray into the Main Jet spray will come out by the needle guide.

Alleyoop

[dencho1992]

Ok so I checked the spark on the valve cover there is spark. I check the fuel pump or petcock and it seems to be coming out at a steady stream its weak but steady. I also tried to put gas into the intake manifold vaccum tube and it did nothing when I started it I put a very little amount tho. also I forgot to mention that my intake spacer is chipped on the left side the chip does not reach the hole so I didn't think it really mattered but I have a new one coming soon in the mail. how much gas is too much gas in the intake manifold? I put at lease a teaspoon maybe.

I also cleaned the carb before these tests I took out each jet took a wire through all the side holes and main one followed by lots of carb cleaner.also u said maybe the tank outlet is clogged what is this?

also when ever I remove my sparkplug it seems that there is no oil on the tip its always dry? is this normal?

here is the fuel pump or petcock putting gas out when I suck on it. no matter how hard I suck it wont come out unless is stop sucking.

[dencho1992]

this is how it pumps the fuel when I start it.

[Alleyoop]

Well it is pumping great, so that is not the problem. But is the motor sucking in the fuel is the question. I also do not like that you poured some gas directly into the intake manifold and it DID NOT attempt to fire. The motor is turning over good and it should at least fire. And you said the PLUG fires when held on the motor. So there are only a couple of other possible problems for a NO FIRE since you poured some gas directly into the intake. It only takes just a little bit of gas not a hell of a lot for it to ignite and get at least a weak fire. LOW COMPRESSION or TIMEING IS WAY OFF .

Have you checked COMPRESSION? How about the timeing have you checked that as well, maybe the woodruff key that holds the FLYWHEEL is damaged and the FLYWHEEL moved and is way out of time. To check that take the valve cover off align the CAM SPROCKET with the two little holes even with the top of the head and LOOK AT where the FLYWHEEL timeing marks are.
And if you can take a picture of where the Flywheel so we can see how it is timed.
Alleyoop

[dencho1992]

thanks for your quick reply alleyoop I will do that when I get home later today. also this morning I noticed sparks coming from my starter when I tried to start the scoot it wasn't constant sparks but every now and then a spark would just come out of the starter is this normal? I don't have a volt meter to test the starter out is there anyway the starter would be the murderer here? also it gets hot after I try starting it for a while but that's to be expected since im just going to town on that start button.

do you think the loss of compression would come from the intake manifold spacer being chipped? when I was changing the head I tried to pull off the spacer between the head and the intake manifold and it broke of a good third of the piece. al tho the hole of the spacer is still intact so I thought it would be fine since the part the broke off didn't look like it was holding any pressure in.

one more thing im doing all this with the plastics off I also disconnected the front side headlights is there a chance there would be a lock on the scoot from starting up kinda how some scoots have a lock on the center stand?

ok one moooore thing. if you know any diagrams of scooters I can use id really like to know what each doohickie in the scooter is im not fond of googling since usually all that pops up is scooter dealers hah

I wish there was a texting hotline for this stuff

[dencho1992]

ok so i got it running and even rode it for a while turns out it was the valve timing set incorrectly haha silly me but i resetted it by making sure the piston up up and locking the lfywheel so its all good there but now there a fuel problem but i will start that in a new thread. thank you everyone for your help im learning alot and im gratful you guys helped me!