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Sorting out an EG 295

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So I put my bike back together 2 years ago with an EG 295 kit, Mid-Top Race gas, heat cycled it a couple times, ran it around the yard for 5 minutes.  It was clearly way off on its state of tune, but I didn't have time to mess with it.  Now 2 years later, and 3k miles away from where I started it, I am finally ready to get this thing ready to ride.  I maybe started it 4-5 times in the last two years to load it in the back of the truck a few times to transport it, It always started second kick.

 

Heres what the jets were then.

 

Pilot - 50

Needle - 2nd clip

Main - 178

Power Jet - 50

 

It ran great as a 250 like this in the northeast at 1k feet, but fell out quickly when I was close to full throttle when it was put back together

 

So here is where I am now:

 

I cleaned the carb, tossed a few new parts at the carb, set the float level and slapped it back together with some fresh C12 mixed 32:1 with Klotz R50. So-Cal at sea level

 

Jets -

Pilot - 42

Needle - 2nd clip

Main - 172

Power Jet - 50

 

I checked timing, and it was at .012 btdc which is I believe around 1.5 degrees advanced, so I set it back to .007 btdc.

 

ran it and set the air screw. I started with a 45, but ended up with a 42 to get the fastest idle at 1.5 turns out.

 

I then ran it up and down the parking lot a few times, and it definitely doesn't completely fall off like it did before the carb clean and rejet. 

 

I found an old compression tester kicking around and tried my hand with that, and got a reading of 195psi. I'm not sure if this means a lot with an old beater of a compression tester...

 

I am pretty new to the jetting game, so here is a pic of the plug, I ran this plug for 20 minutes or so around a parking lot, mostly mid throttle with a couple quick twists to full.

 

Any suggestions? is the plug helpful here? its not quite what I expected to see. Or do I just keep messing with it, needle first then main and see how good I can get it with some plug chops? whats with the little bit of white left on the porcelain?

 

Pipe is a Noleen, Silencer is a Pro Circuit 304

 

Thanks in advance!

Plug.jpg

Bike.jpg

Edited by CodyJ

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I have no specific advice for your 295, but I have found that paying attention to how the bike runs and how hot it gets to be more useful than looking at the plug. I want the plug to be NOT white, and then I tinker until I get little or no spooge, good throttle response at different openings, no weird noises, and a cool running engine/pipe. Kind of hard to describe a cool pipe--it's obviously too hot to put your hand on, but it's not even close to 4 stroke hot.  

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I have no specific advice for your 295, but I have found that paying attention to how the bike runs and how hot it gets to be more useful than looking at the plug. I want the plug to be NOT white, and then I tinker until I get little or no spooge, good throttle response at different openings, no weird noises, and a cool running engine/pipe. Kind of hard to describe a cool pipe--it's obviously too hot to put your hand on, but it's not even close to 4 stroke hot.  

Thanks, I figured I would just keep tinkering with it until I got it right, I don't think I've ever seen that 1/4 moon shape white mark on the porcelain of a plug before, so I'm curious what that means if anything?  Any idea what pipe surface temperatures I should be looking for?  I promise to post some really cool thermal images of it the next time I get a chance to mess with it.

 

and one more pic for good measure, because nobody likes a thread without pics.

 

IMG_2149.JPG
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I have seen plugs like that, mostly with the white part facing the intake.

 

Visually mark the plug on the insulator and twist it in until it is tight, I bet the lighter end is facing the intake

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I am sure a quick call to Millenium Tech could get you a ballpark jet size for your setup: 1-630-825-5645

 

Thanks, Ill give them a call.  And I'll check the orientation of the plug later tonight.

 

and to keep the pics coming.....

piston.jpg

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Well, their website says you will probably have to lean the jetting a bit, and the guy I spoke to on the phone told me he had to go up two sizes on the main, and left everything else the same.  I guess I'll just have to spend some quality time with it.

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I have no specific advice for your 295, but I have found that paying attention to how the bike runs and how hot it gets to be more useful than looking at the plug. I want the plug to be NOT white, and then I tinker until I get little or no spooge, good throttle response at different openings, no weird noises, and a cool running engine/pipe. Kind of hard to describe a cool pipe--it's obviously too hot to put your hand on, but it's not even close to 4 stroke hot.  

+1 for that.  Totally agree. 

 

Not only could I not be bothered checking the plug I think the tune by feel method is better anyway. Ultimately if you're not happy with it, then you feel it.

 

CodyJ,

 

The main tricks are:

 

1. to begin to learn what jetting circuits control which throttle opening amount, and where you are in the throttle range.

2. To be able to feel and hear a rich versus lean condition.

3. To feel if a problem is under how much load, or constant throttle, and how much overlap there is between the different fuel circuits.

 

It's not simple, but you get a feel for it.

 

Some guides say start with the pilot, or the main or whatever. I usually start fixing what feels worst. If I'm not sure what feels worst then I fix the main jet size because testing with wide open and some load is so easy to tune and improve. Then I keep refining.

 

On the PWK38 on the YZ250, in my personal experience only, these circuits do this:

 

- air screw: Tunes the pilot, but seems to have most effect at lower RPMs.

- pilot jet: idle to about 1/4 throttle. Up to 1/2 throttle is impacted by the pilot size if quickly opening.

- slide #: About 1/8th throttle when held quite steady. Too rich and there is a burble here.

- needle clip pos and needle shape/taper: 1/4 to 3/4 throttle.

- main jet: 1/2 to wide open.

 

In my own YZ295, at sea level, in moderate temps and humidity with 40:1 premix, Fatty pipe, stock silencer, 1.65mm squish, 240 psi comp, stock PV spring, and Aus 98 fuel, my motor runs brilliantly with:

 

pilot=45.  Any richer and it has spooge and fussy idling. Any leaner and I get hesitation.

screw=1.5 tuned a little for the day.

slide=#8   to remove the rich 1/8th burble when rolling open or cruising on flat ground. So much better!

needle=W on clip 3. Which is richer than the stock clip 2 pos, but it gives me more responsive broader roll-on torque, and compliments the leaner slide.

main=172.  Which I know is just a tiny bit rich for hotter days, but generally nice. A 175 wont rev out, and makes way less power.

 

My combustion chamber is usually a clean golden brown colour. Motor runs freakishly cool, at least compared to my 4 stroke. Torque and sound is awesome. 

Edited by numroe
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My 295 runs pretty well with stocker jetting.

Gorr says lean it but i dont find that to be the case with mine with a pipe n silencer in so cal.

Im not very heavy on the pipe but when i am, it cleans up nicely.

 

Plug readings arent a good way to jet. 

You may be dealing with the C12 factor. Ive had more than one bike be difficult to tune with C12. Runs rich. Ive tuned a bike with VP110 to perfection and when the owner switched to C12 it was unrideable.

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Your plug looks rich. But the ideal way to plug chop is to warm the bike up on a old plug. Install brand new plug and run full throttle for 1/4 mile.

Then pull the plug and inspect. I would lower the main one size at a time and do a plug chop after each.

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