Picked up a new scoot today By one1 (Read 3,574 times)

[Bashan]

Did you plug the EVAP connection on the airbox? Did you connect the crankcase breather? These bikes are very sensitive to air leaks and must have a certain amount of resistance. Is there a filter in the airbox? You have the gap correct and that's the first thing you should do. The A/F setting is 2 1/2 out. I'm going to move this thread to the tech section.

[one1]

Thank you for all your help. I am balancing multiple pieces of information between people trying to make it right so look and tell me if you believe it will run properly like this. I have plugged everything, tank and all vac wise except the intake to carb.

Here's everything I threw out



What it looks like now (A lot cleaner without those lines everywhere).




Plugged this:



This connects to....



This here:




And these two got plugged up.

[Bashan]

Tank vent must be open:

Crankcase breather must be open:

You'll need to tie the breather off high so that oil doesn't come out. That's why I said you might want to leave it hooked up to the airbox for now. But put a filter in both the tank vent and breather to keep crud out. An old fuel filter works.

[one1]

Thank you i caught those this morning. I'll put it on the airbox for now i was just worried about vac pressure before. Heres a video of what it does without starting fluid. It hits but doesnt catch.



So close.

[cyborg]

I concur the tank must be vented i see a non vented fill cap ,,,you will create a vacuum condition in the tank and the scoot will stall because of fuel starvation,,,and the crankcase must be vented as well

[Bashan]

My impression is that you are not getting adequate fuel delivery. Pull the carb supply line and crank it. See what kind of fuel delivery you're getting. Did you set the valves? That can also cause hard starting.

[one1]

i dont have a vac line, pump, or petcock pushing anything in so i'm guessing i'm looking for suction from a full clear line.

[Bashan]

OK....sorry, I didn't look closely. You have a manual valve on a gravity feed. Unhook the valve from the carb side and turn it on. Make sure you have decent flow.

[one1]

Well the bottom valve was tighter than . The top was fine. After an adjustment they are literally dead on .002in (.05mm) and are quiet as a mouse. I feel like it doesn't rev up with as much authority or power so I will have to adjust the mix screw. Either way I will be happily riding tomorrow for a test ride. Here's pics and a vid.













Here's a video, click it:

[Bashan]

That's a 150? I'd go .004" intake and .005" exhaust. They should actually make a little noise, a slight buzz AFTER it warms up. They're too tight right now and holding the valve open. You'll get crappy compression and it won't rev up right. Did you ever find your engine number? If it's 157QMJ it's a 150.

[one1]

Yes correct case number.


well after adjusting the idle mixture screw it idles and takes off okay but even before I adjusted the screw and after both it bogs and crackles out the airbox quite badly when I give it to much throttle. It can't handle too much throttle or it cuts back and pops.

[Bashan]

Reset your valves they're too tight. You're probably too lean. Try covering up a hole on the airbox with some tape and see what it does. If it gets better you're getting too much air.

[Alleyoop]

Start it up let it warm up at least 5 minutes and adjust your FUEL RATIO MIXTURE to get the highest idle try in both directions in one way the idle will go down in another direction the idle should go up. Find the highest adjustment that gives you the highest idle.


Know If it pops giving it throttle it is getting to much FUEl. If it pops coming down to IDLE it is LEAN either raise the idle a LITTLE using the IDLE SPEED screw or give the Fuel Mixture 1/4 - 1/2 turn counter clockwise.

[Bashan]

Set your valves but then ignore my post and do what Alley says.

[one1]

I did set the mix by the tutorial, that's how I got the idle smooth. It pops both ways. Up and down. Up it bogs and spits. Down it backfires. Annoying that I set the valves by the tutorials and have to change them.

You are not explaining what it does here you say it pops in both direction but then say giving it throttle it BOGS and SPITS.
If it is backfiring decelerating I would suspect a AIR LEAK by the HEADER PIPE that connects to the head(very common if you took off the header and did not put in a new exhaust gasket) or if you did you tighten up the nuts on wrong(most folks that are not that mechanically inclined do. Most will tighten on nut up then the other(WRONG) you need to bring the flange up evenly and just snuge both nuts then criss cross tighten them little more. REASON is if you tighten one up first then the other the gasket will get pushed out to one side and will leak and you will get BACKFIRES on deceleration.

So DOES IT MAKE A POPPING SOUND when your giving it throttle getting up to speed say 30+ mph? If so TO MUCH FUEL IS BEING FEED. You probably have to big of a MAIN JET in it.

Listen to what the motor does the motor will make different sounds and each different sound tells what it needs.
So pay attention to how it actually acts otherwise we are just guessing on what the problem is.
Alleyoop