New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 25, 2014 23:21:06 GMT -5
Hey all, just bought this baby brand new a few days ago, had 0.4 miles on it. Did the PDI, and figured since it was torn down I'd throw in a 47mm BBK, orange coil, UNI filter, plus eliminate the vacuum hose and PAIR system. I have a blue racing CDI, but it makes for a real hard start, so I shelved that for now. Also, both enigne and gear oil were changed right away. Also installed a Keihin PD19J carb, with a 35 pilot and main jet. Valve lash is set at .003 intake, .004 exhaust. When adjusting the A/F screw on the carb, I had to screw it all the way in to get it to idle at a decent rate (no tach yet, so not sure of the actual RPM number). It runs good, I've hit over 50mph (per GPS), but once it's ran for a while when i lay of the throttle at a stop sign it starts to idle real low, almost sputtering. Adjusting the idle screw just seems to mess it up, as it gets either way too high, with the back tire spinning like crazy, or to where it barely runs. Today I rode it for about 12 miles, and when coming home, it just lost all power and died out on me in the middle of the road. Luckily, I was only a few hundred feet from my house, so was able to push it back and coast down the hill. It would start back up, but die instantly. It would die even quicker if the throttle was applied. I've tried adjusting the carb needle, from all the way raised to all the way down and everything in between with no noticeable difference. I've also tried installing the original carb it came with, it wouldn't even start then. I've tried removing the uni filter and reinstalling the original air box - no difference. It starts and idles again, but the idle only seems decent while cold, as soon as it warms up - it starts dropping to almost nothing. I've rechecked the valve lash, still the same as I set it. Anyone have any ideas? I'm at a loss. Help me out here, guys - I love this little scoot and want to make it zoom zoom again.
|
|
|
Post by alleyoop on Sept 25, 2014 23:40:42 GMT -5
From the way you are explaining it, when cold it idls descent and then within 3-5 minutes after the motor warms up it wants to die. When cold the ENRICHER is feeding it extra fuel so after running for about 5 minutes the ENRICHER shuts off the extra fuel so maybe try adjusting the Fuel Mixture on the carb. Alleyoop itistheride.boards.net/thread/12/4ts-carb-tuning
|
|
New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 26, 2014 1:21:33 GMT -5
Can't.
The mixture screw is already all the way in (clockwise). If I turn it out (counterclockwise), the idle gets even worse.
I also tried unhooking the choke on the carb, that made no difference.
|
|
|
Post by xyshannen on Sept 26, 2014 14:18:30 GMT -5
Turning it all the way in like that leans the crap out of your idle.. And just at a guess your running very lean and need to change both the pilot and the main jets to a larger size.
|
|
|
Post by alleyoop on Sept 26, 2014 15:46:51 GMT -5
Well you should already know what part of you problem is the #35 pilot jet TO BIG BRO. That is why you have to turn the fuel mixture clockwise closed so it at least idles half way descent. So if you open it up counter clockwise it just floods out and makes it worse. So put in the smaller Pilot jet that was in there and try that.
Unplugging the ENRICHER will feed it more fuel ALL THE TIME and will make it worse after it warms up. Alleyoop
|
|
New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 26, 2014 19:13:07 GMT -5
Ok, so I tore the carburetor apart again, adjusted the float a bit, and switched the pilot jet out to a 32. Now I have a 32 pilot and main jets. Started right up, idle got adjusted to about 1 1/4 turn out to a real sweet spot. Let her warm up, no issues. Went for a ride, about 1 mile and a half down the road it sputtered at a stop light and died. Took a while to start up, but got her going again. Went another 1/2 mile, and it lost all power while under throttle, which hasn't happened before. Tried starting her again, but nothing. The engine turns over, but nothing there. I'm currently charging the battery, and won't be able to dig in to her until later tonight, as I have a paper to write.
|
|
|
Post by alleyoop on Sept 26, 2014 19:34:49 GMT -5
Great, check the valves and adjust both of them to .003 inchs. Sounds like after it gets nice and hot it is loosing compression. Alleyoop
|
|
New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 26, 2014 21:14:30 GMT -5
Just to be sure, you adjust valve lash while on TDC, right?
Cause that's how I set them to .003 intake and .004 exhaust when engine was cold. Should I let the engine warm up then check the valve clearance?
|
|
|
Post by alleyoop on Sept 26, 2014 21:24:02 GMT -5
Yes, adjust the valves when at TDC, and adjust them when COLD. Alleyoop
|
|
New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 27, 2014 4:23:35 GMT -5
Well, I figured out why it wouldn't start. Spark plug had a bunch of build up on it, to the point the white insulator was cracked. Gonna be a few days before I can replace it. It was an NGK C7HSA, by the way.
Was the build up on the plug due to the too rich mixture?
Also, I double checked the valve lash - still at .003 intake and .004 exhaust.
Damn, back to work tomorrow and Sunday, so no work on the scoot till Monday. Good thing I got vacation time for the next few weeks.
|
|
New Rider
Currently Offline
Posts: 44
Likes: 3
Joined: Sept 20, 2014 16:24:02 GMT -5
|
Post by blue on Sept 27, 2014 4:38:22 GMT -5
You said you took some air line off in your frist post.some of theam you need to help feed gas to the carb.
|
|
New Rider
Currently Offline
Posts: 7
Likes: 0
Joined: Sept 25, 2014 23:06:43 GMT -5
|
Post by ohnotnotagain on Sept 27, 2014 5:28:34 GMT -5
I got rid of the stock vacuum petcock and replaced it with a manual on/off petcock. The vacuum line from the petcock to the intake manifold got removed and replaced with a vacuum plug.
The other line was for the PAIR emission system, and that got eliminated completely as the new cylinder head came with that plugged off, so no need for a custom plate.
Since I eliminated the stock air box, and replaced it with a cold intake foam filter, the line running from the valve cover to the airbox got extended to 2 1/2 feet, and I mounted a small foam filter at the end of it, and placed it under the tank so it can vent and I don't have an oily mess on my hands.
|
|