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Discussion Starter #1
Ok so im trying to find out if my engine is running lean or rich :thumbsup: Done some research and i under stand i need to run the bike till its warm. then hold the throttle at the rpm i want to check my mixture at e.g WOT and then kill the engine at that rpm.

But few questions after i done that

1. After killing the engine at the rpm i want. do i have to stop asap on the spot? or can the bike roll back to the garage?

2.After killing the engine, can i let go of the throttle??

3.After killing the engine do i let it cool right down??

4. What do the collours mean?

Thanks agin :D sorry if this has been posted befor and i missed it
 

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Stormin' Mormon
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310 Posts
Instead of actually riding it, I would warm the bike up then give desired amount of throttle while the rear tire is off the ground. I don't think load is a factor when adjusting the mixture. Someone correct me if im wrong.

Id let the spark plug cool down a little just so you don't burn yourself.

The color your looking for is a golden brown color. If its oily and pure black its to rich. If it's dry and silver/gray its to lean and have a high chance of seizing the engine. Always better to run on the rich side.
 

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Discussion Starter #3
Instead of actually riding it, I would warm the bike up then give desired amount of throttle while the rear tire is off the ground. I don't think load is a factor when adjusting the mixture. Someone correct me if im wrong.

Id let the spark plug cool down a little just so you don't burn yourself.

The color your looking for is a golden brown color. If its oily and pure black its to rich. If it's dry and silver/gray its to lean and have a high chance of seizing the engine. Always better to run on the rich side.

Thanks for replying. I thort i read that load was a factor??
 

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But who prays for Satan?
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hmmm, it could be, but being honest, I do not see how applying a load would change the fuel / air mix, but it would keep the rpm's lower than with no load...

Realistically all that matters is that you check the different throttle positions, idle, needle, and main jet!
 

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Discussion Starter #5
I just dont it. let it warm up for a few mins then wot it for about 10secs then killed it...





Plug was still hot haha. So i guess im running rich??? what you think?
 

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hmmm, it could be, but being honest, I do not see how applying a load would change the fuel / air mix, but it would keep the rpm's lower than with no load...

Realistically all that matters is that you check the different throttle positions, idle, needle, and main jet!
It changes it a whole lot and load does play a factor because the heavier forces weight down the powerband making it run richer on the bottom to topend momentarily.......If you keep on the throttle long enough eventually it will clean itself out but over time will kill the plug faster from the slight fouling............

You must be thinking Diesel logic Nick where they arent effected by altitudes,,temps and such............

I tuned an X1 for my nephew[95lbs]to ride and when I went to ride it [190lbs]I had to retune it on the lsn to get a descent takeoff


Those stock float type carbs were designed for lawn equipment applications for longterm continuous useage not riding toys......The carb design was ripped off from the early 80's Homelite backpack blower........With them carbs varying velocity wreaks havok on tuning because youll always be tuning them......One of my young neighbors that has one says that a day it runs right is a good day to ride......That was until I fixed it for him by ditching the stock carb and installing a 14/14 delrep carb ...Im more partial to pumper carbs though for their cleanliness,,ease of tuning aswell as the power they pull from these little engines.............

A carb with a single mainjet only isnt a very efficient carb for a driven object...The 14/14 Del reps are still single mainjet designs but atleast they have a 3 hole atomizer in the venturi that progressively gets richer as the mainjet needle gets higher so you can tune it easier and get more enjoyability out of it............Instead of thinking topend speeds youre gonna need to be thinking torque and pulling power[gearing]
 

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But who prays for Satan?
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Strictly speaking about air flow, vs load vs RPM, I could see it.

Who knows, The schooling on carburetors I got was "Rushed" to say the least, we spent more time looking at fuel injection, and to be honest, Working with Diesels so much lately is NOT helping! :p

I think Cam could be right, do it with a load, since that is how it is going to be run (with you on it) !!
 
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