PLEASE HELP!!!!!

The spirited black sheep of the Genuine lineup

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Terescenko
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Joined: Sun May 01, 2016 1:52 am
Location: South Florida

PLEASE HELP!!!!!

Post by Terescenko »

I just recieved my brand new stock carburetor from scooter works for my genuine roughhouse. I had trouble drilling the mixture screw on the current carb so I decided to purchase the carb WITH the mixture adjustment screw. I swapped the jets from my current carb to the BRAND new 1...she fired right up...when I recieved the carb, I marked where the adjustment screw was (1 turn out). I have tried EVERY SINGLE possible adjustment up to 4 turns out. Turning 1/8th at a time, listening for best sound, even test drove for an hour + stopping every half mile adjusting 1/8th at a time. The mid range and acceleration off the line is terrible....wide open is okay, but as soon as I let off and then accelerate again, I cannot achieve the maximum Wide open speed again....i was so frustrated I put the original carb back on and swapped the jets again. Scooter is rough at idle (because I cannot adjust the mixture screw) BUT it takes off like a rocket and my mid range is PERFECT. I have no idea what could be wrong...the scooter seems to have A LOT more power with the original carb...
dasscooter
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Post by dasscooter »

If you transferred the jets over to the new carb, try drilling a couple holes in the air filter cover. It'll still be filtered and all, just have a little more air coming in.

You can try this theory by taking it around the block with the filter and cover removed. Don't do this if you have the stock jets in it, it will be way way too lean.
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Uni filter

Post by Terescenko »

Thanks for quick reply Dasscooter...I have a uni filter on there...I even tried to take the uni filter off and run it for a minute without an air filter and I saw NO difference...
2014 roughhouse 50
10,000 genuine miles
72cc BBK kit
NCY super tranny kit
7g sliders
Performance exhaust (some cheap prima pipe clone I found on eBay for $95 *Does the job! )
Stock carb
Uni filter 35mm
#95 main
#35 pilot
Brand new fuel lines, fuel filter, vacuum lines, spark plug, and belt.
dasscooter
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Post by dasscooter »

In that case, work backwards by reinstalling your stock airbox - the small diameter of the stock carb may want more backpressure than a pod filter can provide. If you gain bottom end and lose top end, drill a few holes. Experiment until a happy medium is found.
dasscooter
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Post by dasscooter »

Bumping up the pilot jet wouldn't hurt either
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Stock carb

Post by Terescenko »

I understand where you're coming from, I just do not understand why the original carb on my scooter runs great at mid range and wide open while the EXACT same stock carb I just bought from scooter works is not performing like the one that came with the bike...they both are identicle...the roughhouse comes stock with a 16mm carb...I know from past experience this is plenty for a 72cc kit (not trying to be speed demon with a 21mm+lol) I'm stuck with 2 OEM genuine roughhouse kenieth carbs. On one I can't adjust the mixture but the power is great, on the other I can adjust the mixture but it runs like crap
:(.
dasscooter
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Post by dasscooter »

Isn't the mixture screw on the original carb now destroyed/gone?
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Post by Terescenko »

Half way gone....it performs exactly the same way as it did before I touched it and drilled into it...thankfully it didn't totally destroy the carb!
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Post by Terescenko »

Half way gone....it performs exactly the same way as it did before I touched it and drilled into it...thankfully it didn't totally destroy the carb!
dasscooter
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Post by dasscooter »

Are you reusing the same slide (throttle piece that threads down into the carb). If not, one may be shimmed and the new carb slide isn't.
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Slide

Post by Terescenko »

Yes, I am reusing the same slide. I THINK MY NEEDLE IS GETTING STUCK....This can possibly be the issue??? When I first inboxed and disassembled the carb and removed the new slide, the spring popped out and the needle was stuck inside with the slide. Hmmmm this could definitely be it! I had to use needle nose pliers and go in through the intake manifold to gently lift the needle out of the main jet holder? (Not sure what this piece is called).
dasscooter
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Post by dasscooter »

Hmm, that could be a problem, yes. I've never seen that before though
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Z

Post by Terescenko »

Dang it...that wasn't the problem I just tested it out....that carb is brand new there's no way there's an issue with it. One thing I noticed is the more I close the screw, the better the scooter runs. It ran the best almost to where I was closing the mixture screw to the point where my scooter would die. Does this mean I need a bigger main or pilot? Again thank you for responding...I appreciate it
dasscooter
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Post by dasscooter »

The mixture screw really doesn't do too much, it only slightly comes into play during 1/4 throttle or less.

This is how you adjust the mixture screw in general:

*Let the engine idle for about a minute
*Tighten the screw almost to the bottom, the RPM's will lower and it will want to die
*Slowly loosen the screw until the idle speed doesn't go any higher. Usually 1.5-2.5turns

How's that spark plug look? I'm thinking you need a larger pilot jet if you still have the original 35 with a big bore and a pod filter. A 40 may do the trick.
Terescenko
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Posts: 21
Joined: Sun May 01, 2016 1:52 am
Location: South Florida

Update

Post by Terescenko »

Dasscooter thank you for reply...I have been extremely busy lately. Overall, I ended up raising the needle on the carb. I am using the brand new carb with the adjustable mixture. A 38 pilot, 100 main and my spark plug is a cardboard/coffee color. Scooters running great and awesome from take off to top end. Looking to maybe upgrade my final drive so it won't work as hard to cruise at 45...thank you for the help! I currently put 1500 miles on the 80cc kit and she's finally tuned and running like a mean machine!
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