24.50mm Keihin carb installed - won't start? By HotStuff2 (Read 1,277 times)

[HotStuff2]

So, I got the new 30mm Keihin carb on Friday, and since it's raining today, figured I'd pull the (replacement) stock carb off, and install the new one.

Got everything hooked up, and...it turns over, but won't start.

Possible reasons?

edit: It's a 24.50mm, NOT a 30mm. D'oh!

[terrilee]

aww really ?

go to home page, many articles to read

[HotStuff2]

I have, but can't figure it out.

Hoping alleyoop sees this and has some ideas, it's the carb he recommended.

[terrilee]

yea but ALLEY has been working on scoots & esp carbs for years

[HotStuff2]

Exactly. This is the replacement carb he recommended, so perhaps he might have some better insight.

[bullet]

Do you have a vacuum petcock and did you reattach the vacuum line? If so open the float bowl drain with the screw at the bottom of the carb. with the drain hose in a container and see if fuel is getting to the carb. This will help to remove any air in the line. If not back track to the tank.

[HotStuff2]

No petcock, the Taotao uses a fuel pump. I put the stock OEM carb back on, and it still won't crank. I put everything back the way it was, and no go.

[HotStuff2]

I gotta be missing something. Worked with stock OEM carb; took off stock OEM, replaced with Keihin card: just turns over. Took off Keihin carb, put stock OEM carb back on, just turns over. Everything is routed the way it was when it was working.

Gas is getting to both carbs (the Keihin had gas in the float bowl.)

[gatekeeper]

Pull your plug and check that it is sparking when grounded to the head. I read in another of your posts that you were going to set your valves to .002/.0015. If you did that is really on the tight side. Try .004 intake and .005 exhaust. If you are getting spark, try spraying a little gas or carb cleaner or WD40 in the vacuum nipple on the intake to see if that makes it pop when you crank it. Double check for any electrical connectors that may have been jarred loose during the carb change.

[HotStuff2]

With the standard NGK plug (which I just put back in), I see a very weak spark. With the NGK Iridium IX plug, I don't see a spark at all.

Don't see anything that's loose or not connected.

[tvnacman]

check your engine ground . Do you have a meter . check your kill switch .
John

[HotStuff2]

If the kill switch is engaged, it doesn't even turn the engine over. The ground is fine as well from what I can tell.

This is VERY frustrating! It should have been an easy swap-out/swap-in, up-and-running. WTF...

[tvnacman]

is the spark plug getting wet ? Could you have cracked the manaofold ?

John

[HotStuff2]

No, all is well. I put the battery on a charger for over an hour, and she cranked right up. Don't know WHY that did the trick, but that's the only thing that explains it.

The NGK Iridium IX spark plug is in, the Keihin carb is installed, and she's idling normally. I'll be taking her out on the road tomorrow to test the a/f mixture under load, but it should be fine.

[alleyoop]

It was the Idle Speed screw that needed to be adjusted to open the butterfly, the butterfly was complety closed on the new Keihin Carb. The Keihin Carb the Idle Speed screw is Flat while most of the clones have a Idle Speed Screw with a point on it. Don't want to be rude Hotstuff2 but you have to tell it like it is to also help others.

So for anyone putting on a new Carb.
Before you even put it on:
1. Back out the Idle Speed screw off the Controller
2. Then Turn the Screw Clockwise until it touches the Controller
3. Then Give it at least 1 full turn more

It may need even more but if it starts there and the idle is to high you can always lower it if the idle is to low on the cold start turn it a little more clockwise to raise the idle.

Once its warmed up at least 5 minutes you can adjust your Fuel Ratio Mixture and Idle.

The Butterfly has to be a tiny bit open for it to start if its completely closed it will not draw gas down into the intake.
Alleyoop