New HS motor very rough idle

Hey there, working on my 1st build with a HS 4 stroke. First off I'll let you know I live at altitude here in Denver the mile high city. The engine starts up easily enough but didn't idle out of the box without adjusting the idle screw. Not sure if that's normal or not.

When at idle, it surges, can't supply sound but will try typing it out.

dit dit dit rrrrrrrr dit dit rrrrrr dit rrrrrrrrrr dit dit dit dit rrrrrr make sense?

Anyway, noticed another adjustment screw which I've fiddled with but don't know what I'm doing. Does that adjust air or fuel?

Ready for suggestions from folks that run this engine and hopefully at altitude.

well usually if carbs have two screws
one is for gas and the other is for air intake
may be too late for this
when I am messing with anyTHING other than an idle screw I count any turns in or out
makes it easy to come back to where we were
even if you have messed THINGS up a little
you should be able to dial it in -- with a little playing around
slight adjustments are best for a nube
remembering where you started

MM

Have 2 screws, one for idle only, the other is what the inquiry is about. I take you aren't running this motor?

Appreciate the quick reply though.

mmachine said:

I take you aren't running this motor?

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correct not running that one
have worked on various types over years
so you adjusted the air intake screw and not sure where you started ??
if so air screw can be adjusted while running
if you can get it running

if we are not sure where to start
I would screw screw all the way in and come out 1 1/2 turns
go from there

or someone on site with same engine can check and see how far out screw is ??
contact a couple of guys here on site with same -- these ones will help you

MM

mmachine said:

Have 2 screws, one for idle only, the other is what the inquiry is about. I take you aren't running this motor?

Appreciate the quick reply though.

Click to expand...

This was posted by Quenton Gunther:carburetor

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In order to adjust the carburetor it is necessary to warm the motor up first. The motor should have at least 5 minutes running time before any adjustments are made.

On the left side of the carburetor near the front is the idle mixture screw.

On the EZM motor the idle mixture screw is a fuel adjustment, not an air adjustment.

Simply adjust the screw for maximum idle, and then turn the screw approx 1/16" counter-clockwise [slightly rich].

Check the throttle response, and adjust the mixture if there is a hesitation. Turn screw clockwise if it "bulks" and then catches on [rich], or adjust screw counter-clockwise if it accelerates and then drops off quickly [lean]. It worked for me!! MotoMagz

In order to adjust the carburetor it is necessary to warm the motor up first. The motor should have at least 5 minutes running time before any adjustments are made.

On the left side of the carburetor near the front is the idle mixture screw.

On the EZM motor the idle mixture screw is a fuel adjustment, not an air adjustment.

Simply adjust the screw for maximum idle, and then turn the screw approx 1/16" counter-clockwise [slightly rich].

Check the throttle response, and adjust the mixture if there is a hesitation. Turn screw clockwise if it "bulks" and then catches on [rich], or adjust screw counter-clockwise if it accelerates and then drops off quickly [lean]. It worked for me!! MotoMagz

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Thanks, I'll give that a try. I did a lot of searches but misspelled carburetor.

is that a thumbs down?

What's that red thing top left above my previous post?

Is that a thumbs down? Something I said?

Please explain.

mmachine said:

What's that red thing top left above my previous post?

Is that a thumbs down? Something I said?

Please explain.

Click to expand...

Hey not from me!! You must of hit one of the icon buttons at the bottom of the post page.MotoMagz

mmachine said:

Hey there, working on my 1st build with a HS 4 stroke.

Click to expand...

what gearbox are you using?
did you buy a kit? from who?
how do you like it?

thanks

Hey not from me!! You must of hit one of the icon buttons at the bottom of the post page.MotoMagz

Click to expand...

LOL, no not you, you gave me a precise answer that I can't wait to try out. I must have hit a button unknowingly will go forward with caution.

What kit/gearbox?

Bought from BoyGoFast on ebay which I won't do again as it's not the quality I had in mind. Haven't finished bike one yet and working on #2. Always waiting on parts of some sort and must keep moving. Will be using the EZM kit because the drive system is what I'm looking for.

Realized it's better to go with quality from the beginning if I want to be happy with the finished product. If you go cheap you'll end up spending $ to make it right latter anyway so doing it right in the beginning saves time, money and agrevation.

I'll post pics when things move farther along.