2001 EC250 Jetting

D

ducncover

New member
Okay fellas. I just bought a 2001 EC250 and it runs like garbage. Here is my setup:

Currently running 50:1 91 Octane pump gas at sea level an 75* F.
172 Main
38 Pilot
#7 Slide
N1ED Needle
A/S 2 1/2 out

Bike runs like garbage off the start. Doesn't want to come up on the pipe at all in first gear. Quick shifts through the gears it runs pretty good, but off idle and off the line WOT it is running really rich. Fouled a plug this morning and started investigating. The clip was on the middle position and the plug was black and wet. I moved it up one notch and it seems to have helped with the mid range ridability, but is still running bad down off the line WOT. I am thinking this is a needle issue. Any recommendations.
 
Do all the basics first... Start with your air filter, make sure it's clean and properly (not excessively) oiled, re-pack your silencer - this is much more important than most people realize - Make sure the float height is correct, if it's not right, you will never get the jetting right. Check the operation of your power valve, there are several posts on how to do that here... check the timing. you can either use a degree wheel or BTDC measurement. OOps! I forgot to mention the reeds, If they're warped or chipped it can make jetting seem bad... I would also suggest that you might have a bad or worn right -side crank shaft seal. This would most certainly foul a plug and make the bike run rich and oily. They're hard to check unless you have a way to pressurize the crankcase - you might be better off taking it to a shop for that, (or maybe not...) Lastly, you might just need a new piston and rings, do a compression check and compare with some others around here. But most importantly, Don't try to change everything all at once, this usually leads to confusion. Try cleaning and re-packing first so you have a good starting point, then make one change at a time until you get it right. It won't take long (it's a 2 stroke! there ain't many moving parts:D )
Be patient, and good luck.
'TOOL
 
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BT,

Thanks..

The Air filter is new and oiled. I have not checked the packing, but there is plenty of spooge coming from the pipe. I pulled the reeds yesterday and really dont know what I am looking for. They are not cracked, but the top reeds sit flush with no visible light coming through. However, the bottom reeds seem to have a 1/32 to 1/16 in gap and do not look fully seated. I am guessing that this may be allowing too much fuel in at initial throttle.

I just attepmted to pull the power valve cover (left side) and noticed that the oil seeping out is black and sooty. The previous owner did absolutely no maintenance on this bike. I will be changing it today.

I think the compression is fine, it starts first or second kick every time. The wierd thing is that in neutral the throttle response is fantastic and the bike sounds like it it running clean, just a little smoky. It's only off the line and rollons that it boggs down. It's been a long time since I have owned a 2t. Hopefully I will figure this problem out soon.

EDIT:
After reading some posts on here, the best way to describe my problem is: very rich on the bottom and spooging up causing it to 4 stroke and splutter when I open it up after a period of low rev / low throttle running and off the line roll on.. This description is spot on to what mine is doing. If I am running at speed and going on and off the throttle I really don't notice any problems. Please shed some light on the problem for me.
 
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Update

Okay, I have gone through everything on this bike and have come to the conclusion that it must be the reeds. My reasoning makes sense to me, but I will throw it out for a quality assurance check.

Pilot (slow jet) is clear and is small enough for this weather and altitude based on talking with several friends.

Main Jet may be a little large but the bike runs fine at WOT and at high RPM.

Needle may be a little off but shoudn't effect the low down response that bad and the bike (according to the guy I bought it from) ran fine last season. I will order an LTR kit today just because, but I really don't think that the needle is my main issue.

Now for the reeds. The reeds are not frayed but one has a small 1/32 -1/16 gap between the petal and the rev plate. I think that too much fuel is being pushed passed at low rpm and causing the motor to bog out. Initially, it was very bad. Since only the bottom set had the gap, I flipped the reeds and although the problem didn't go away, the syptoms did change a little. I will replace the reeds and post a follow up report.

The good thing about this experience; it has forced me to become reacquainted with the 2t motor. Although I used to ride 2ts a long time ago, my dad did all of the maintenance. I am now the one maintaining my kids bikes. Thanks for the great website.
 
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Update

I finally gave up and took my bike to a local shop. They seem to think that the lower right crank seal is bad since the bike seems to be fouling the plug with ATF fluid. We shall see. looks like BIGTOOL was spot on.

BIG TOOL said:
... I would also suggest that you might have a bad or worn right -side crank shaft seal. This would most certainly foul a plug and make the bike run rich and oily. They're hard to check unless you have a way to pressurize the crankcase - you might be better off taking it to a shop for that, (or maybe not...)
Click to expand...
 
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