Bogging even w/ new carb By domdom13 (Read 519 times)

[domdom13]

Hey everyone, this is my first post in the forum. I recently bought a Chuanl 2008 150cc 4-stroke scooter that had been sitting for over a year. It ran fine for about 500 miles then started bogging at different acceleration points until it would hardly reach 10 mph. I ended up buying a new carb offline and just installed it and it's still bogging. I initially thought it was the jets clogged or something but obviously not. White smoke comes out of my exhaust now too when pulling the throttle on it's stand. There is also a whistling sound that seems to be coming from where the belt is. If you have any suggestions please help a brotha out. Many thanks!!

[beebo]

I'd be looking for the source of that whistling sound, Might be an air leak. There's usually only one vacuum port on the intake, but it will tee off to supply vacuum to emissions stuff, fuel pump, etc. At 5 yrs old, they need to be replaced. I would be checking the fuel system, too-pump, filter. Check for a cracked intake manifold, too.

[kz1000st]

Have you adjusted the valves yet? The whistling might be blow back through a partially open valve. Brrrrrrr.

[domdom13]

I checked around the engine and carb for any possible air leaks. And I do feel some air coming from in between the engine and the carb. Would that cause the immediate bogging? I don't know if there is a place where you're maybe supposed to feel air releasing from the engine too? Definitely a beginner in this field. The white smoke is fairly new as well. Didn't start until after I cleaned out the exhaust!

I haven't checked the valves. Where are they located? And what type of tool do I need to adjust them? I need a reading correct.

[Alleyoop]

Have you adjusted the Carbs Fuel Ratio Mixture? If not follow this procedure and TAKE YOUR TIME.
www.scooterdoc.proboards.com/index.cgi?board=intake&action=display&thread=1499

Also to adjust the valves you need a FEELER GAUGE KIT they are not expensive any AUTO PARTS store will have them. BUT make sure it has a .004 and .005 inch feelers in the kit, some kits start with .008 inch feeler and those are for cars.
Here is how to adjust the Valves: You will also need a Socket and Open End wrench set or get a Open end 9mm wrench to fit the LOCK NUT on the rocker arm adjuster.
Alleyoop

[domdom13]

Awesome that video should help. I will go get a kit tomorrow after work and test it out. Any ideas on what the main causes of the whistling could be? It sounds like it could be coming from the belt but I could be mistaken since it's right next to all the hoses and such.

Thanks alleyoop!

[Alleyoop]

If you could get a video of the whistling moving the Video close to different parts to maybe be able to tell where and what is causing it would be a big help. Otherwise we are all just guessing.
Alleyoop

[beebo]

You know, somewhere around here I have a tool that I made from one of my wifes' stethoscopes. (she is a licensed CNA) I took off the disk shaped dealie on the end and attached a piece of steel brake line tubing and it makes a wonderful tool for listening to motor noises. Too bad it was her favorite stethoscope.

[domdom13]

Ok, so I went to start it and take a video of the whistling sound and now it won't even start. Last time I worked on it it started right up. I am so confused. Bran new carb, and now I'm worse off than I was before.

[Alleyoop]

Turn the fuel ratio screw clockwise until it stops and then turn it COUNTER CLOCKWISE 2 1/2 turns that is a good starting point. It should start if it is getting gas and the plug is fireing. Unless it is flooding or something else is wrong. Do you have a good strong battery, Take a Video of you trying to start it so we can see how the motor is turning over.
Alleyoop