150cc gy6 engine problems By blazef20 (Read 39,055 times)

[Alleyoop]

Blazef20,
Well if you do not have a spare Intake take some Duck tape or Electrical tape and tape the Intake where it is cracked. It is probably sucking air from there. What you call the Air/Cut Valve which is on the Right side of the Carb next to the Throttle cable is for Deceleration. That feeds fuel when you have the throttle almost all the way open and let go. That should be getting Vacuum so it should be connected to the the Intake nipple either through a "T" connector or a "Y" connector. Normally you have a hose from the INTAKE NIPPLE to a "T" then the AIR/CUT also connected to the "T" and then the FUEL PUMP or Petcock Vacuum connected to the "T' or "Y". They all need Vacuum, the only one that would not need VACUUM would be if you just have a FUEL SHUT off from the Tank to the Filter then to the Carb.

So connecting the Air/Cut off(deceleration Diapghram to the Intake Nipple if fine if that is all that VACUUM is needed for.
Alleyoop
Here is the my Connections: Notice the Brass "T". The bottom hose is going to my Fuel Pump.



Alleyoop

[blazef20]

i checked my air/fuel mix. tuned it and it runs alot better now, ALOT. idles awsome. i do have a couple small cracks in intake manifold, so im going to purchase one. Any suggestions performance wise on one? Now that i got it running im going to start replacing old stuff with new. try to keep er goin as long as i can.

[Alleyoop]

Blazef20,
That is great!! Performance intake will not give you anything noticeable. So a standard one is just fine. What will give you the most bang for you bucks is a performance Variator and weights. What you try to do there is tune it so the belt goes all the way up the Variator more top end speed. Mark your variator and run it at WOT then you will know if your belt is reaching near the edge of the Variator. Mark it like this 1/2" by 1/2" and then you will know if you can get some more top end out of it.
Alleyoop

If you have 1/4 or more mark left you are looseing around 5mph top end speed.

[blazef20]

ill have to check that out thanks alot. by the way them is some nice trikes.

[blazef20]

ok so i let the dang thing sit and now it wont even start. ok heres what happened. i changed fuel lines but i think i got a bigger size then originally, i wonder if that could be the problem. maybe to much gas now? Remember i drilled the petcock so no vacuum, just gravity fed. gas in the lines. hmmm?i messed with the air/fuel nothing so back to original position. i checked spark none so i took my new cdi off and put original on. SPARK!! still no start. what the @#$%. my luck, it was running good to. Im not sure what to do now. but im not giving up.

This is the cdi and coil pack i have. i took the cdi off because it would get no spark with it, but earlier it did it was runnin awesome

[Alleyoop]

Blazef20,
Did you put on a new Fuel Filter? If so you may have put it on backwards. The Wider Part of the Fuel Filter shoulb be toward the CARB. Also the Fuel Line from the tank to the Filter should be 1/4 ID no bigger than that. Now the Fuel hose from the Fuel Filter to the CARB should be 3/16 ID and that is because the Nipple on the Carb is a 3/16 nipple.

One other thing, if you changed the hoses and it is gravity fed now there should not be any dips in the fuel line to the carb. The Hose now that it is gravity fed CANNOT be LOWER than the Carb.
Alleyoop

[Bashan]

Wow Alley, great mini-tutorial on the air cut valve. Most people just don't understand that thing and ignore it. Good tip on the variator too. OK blaze, if I understand the time line it was running at least adequately until you changed out the lines. If that's the case then it was something that happened while you were doing the lines. 1/4" is fine, anyway the float bowl valve will only let so much fuel in and then it stos so I can't see bigger lines as the cause. Alley's right, make sure the line runs downhill and doesn't have big dips. Just approach the problem as what happened between the two points in time when it was running and then it wasn't. Rich

[blazef20]

Ok I checked the fuel lines and no dips or twists or n e thing.i cut a little more off so it was a straight line to the carb. i took the fuel filter off and tried it. Still nothing. im still getting spark. i think it might be time for a new carb. wonder if it could be the spark plug itself. its a new one but trying to start it and running it when it was rough could have fouled the plug right? i dont get a blue spark its like red and cracking up.

[blazef20]

i will keep that in mind Dr.JR. Carb cleaner. What about the auto-enricher. could it be sticking maybe. Im going to try alleyoops idea about taking it out and bypassing. just to see if that has anything to do with it. if not im going to try and take the carb off again and clean it. Would having the air cut valve line hooked to manifold vacuum do this? I am Stumped again. maybe ill just bring it to the shop and have it looked at.

[Alleyoop]

Blazef20,
Before you get a new Carb, Turn the Air/Fuel Mixture Clockwise until it stops DO NOT FORCE it shut just until it stops and when you do this COUNT the number of Turns it took to close it.

Then Turn it Counter Clockwise 2 1/2 turns and try to start it. Also take a look at your Fuel Filter and see if there is gas in it.

Reason I am saying this is because when it would not start you turned the Air/Fuel mixture so now it could be that it is TO CLOSED and not allowing enough fuel in.

If it starts then you can FINE tune the Air/Fuel Mixture.
Alleyoop

[blazef20]

ill try it now. What about the spark though I said it was like a reddish blue and crackly. what does this mean

[blazef20]

ok freakin weird, just for kicks i went out today and tried to start it and bam fired right up . though i had to hold the throttle all the way to start but then it was fine. rode around a lil (remember its still in the kart) it rode fine except for when i give it more then half gas it putters a little i back off the gas n give it gradually and she'll go. not as much speed as before but that could be just an adjustment that needs to be made. im going to let it sit for a couple hours and see if itll start after that.

[Alleyoop]

Blazef20,
Make sure the two connectors on the Coil are on good and not loose. Also try Screwing the PLUG Cap Clockwise on the Coil wire. That is the part that goes on the Spark Plug its called a Cap. The Cap Screws onto the Coil Wire it may have come a little loose from you taking it off and on. Sometimes inside the cap the Brass clip also break and does not make good contact with the Sprak Plug.
The Cap I am talking about:
www.buggypartsnw.com/home?page=shop.product_details&flypage=flypage.tpl&product_id=210&category_id=18


Sounds like it needs some Air/Fuel Mixture adjustment.

ADJUSTING YOUR AIR/FUEL MIXTURE:
YOU WANT THE HIGHEST RPMS OUT OF THE AIR/FUEL MIXTURE SCREW:
This is for you common CVK Carbs that have the Air Fuel Mixture Screw Near the INTAKE goint to the Engine. Other Carbs may have the Air/Fuel Mixture On the Air Filter Side with those JUST CHANGE the WORDS "CLOCKWISE to COUNTER CLOCKWISE" and "COUNTER CLOCKWISE to CLOCKWISE" other than that same thing applies.

Before you start it Turn the Air/Fuel Mixture Screw CLOCKWISE UNTIL IT STOPS do not tighten it just until it stops BUT COUNT how many TURNS IT TOOK TO CLOSE it. Then Turn it COUNTER CLOCKWISE the same amount of turns back to where it was.
Then Start your scoot and Get The Engine Nice and Hot about 10 minutes so that the Enricher is no longer Allowing Extra Fuel to come in. Then do the following to fine tune the Air/Fuel Ratio:

RICHEN THE AIR/FUEL MIXTURE:
1. Turn the Air/Fuel Mixture COUNTER CLOCKWISE 1/4 turn and wait 10-15 seconds to let the engine catch up with the new setting.
a. If the RPMS go up REPEAT 1 UNTIL the RPMS GO DOWN OR NO CHANGE.
b. Then TURN the Air/Fuel Mixture 1/8 CLOCKWISE and that should be your highest Air/Fuel Mixture setting.

"""If on the FIRST 1/4 TURN from the STARTING Position IN #1 ABOVE the RPMS GO DOWN OR NO CHANGE , turn the Air/Fuel Mixture Back the 1/4 turn to the Starting position and wait 10-15 seconds until the engine catchs up and go to #2"""

LEAN THE AIR/FUEL MIXTURE:
2. Turn the Air/Fuel Mixture CLOCKWISE 1/4 turn and wait 10-15 seconds to let the engine catch up with the new setting.
a. If the RPMS go up REPEAT 2 UNTIL the RPMS GO DOWN OR NO CHANGE.
b. Then TURN the Air/Fuel Mixture 1/8 COUNTER CLOCKWISE and that should be your highest Air/Fuel Mixture setting.

IDLE SPEED SCREW:
3. If after adjusting your Air/Fuel Mixture your idle is to fast Turn the IDLE SPEED SCREW COUNTER CLOCKWISE until your Rear Wheel JUST Barely wants to Turn or around 1500-1800 rpms.

4. If 1 or 2 above DOES NOT produce any RPM Change you most likely have a CLOGGED PILOT JET "OR" you did not get the ENGINE HOT ENOUGH and you were working against the ENRICHER which has not yet closed off the extra fuel. If the engine was nice and hot running for about 10 minutes and the Enricher was off then its time to take off the Carb and Clean out the Jets and all the Carb Passages.

If adjusted correctly you should be able to give the Throttle a QUICK half turn and the Engine should REV UP with no bogging hesitation and get a nice VROOOOOOOOOOOM. The Rpms should come down nice and settle at the Rpms you set your Idle to.

Alleyoop

[blazef20]

how do u know if its running to rich or to lean boy i sound like a newb huh? sry guys im new to this stuff

[Alleyoop]

Blazef20,
Easiest way to determine which is causing the problem Rich or Lean is this:
When it acts up Stumbles Brups Bogs etc..:

BACK OFF the throttle a Little about a 1/4 turn and HOLD IT THERE:
1. If it Speeds up and or Settles down Your running LEAN.
2. If it STUMBLES and Then Speeds up Or Settles Down then your running RICH.

Now If it BackFires that means you are running LEAN or you have a Header Flange Leak(the Header connected to your motor is leaking).
Alleyoop