How much four-stroking is NORMAL?

[bob sagass]

I would like to state in advance that this post may contain profanity.

I'm new to two-strokes. And I probably should have bought a different bike to start with, but I have a 2003 ec300 (with plates). Maybe it's 2002.. I keep forgetting. Anyway, I've gone down to the smallest pilot jet (35), and I'm still four-stroking just off throttle while cruising. In fact the 35 doesn't seem much different than the 40. Is this normal?

Another thing is the air box. I don't really see anywhere where the freaking air is supposed to go in. Is it just supposed to get sucked through the cracks? There's something on the bottom that looks like it might be a port but it looks like it's just walled off. It seems to run better without the airbox side cover on the bike. Jetting is "stock?": N1EF/180/40/3rd clip/slide 7. Well, as of right now, the pilot jet is a 35, and I don't see much difference besides that it stalls out easier.

When I got the bike the top end was INSANE, but it pissed fuel on the sidestand, which I removed. What a freaking joke. Just like the rear brake lever, the switchgear, the stupid drywall screws in the fuel tank, the dog shit chain guides, the chain adjusters from 1911, the stupid exposed rear brake master cylinder, oh yeah, and all the pressed on nuts on the frame that fell off the first time I rode it. Ok I'll stop. Anyway, I adjusted the float and never seemed to get that same top end back, although today, in the dead of winter, WOT seemed ACCEPTABLE, whereas in the summer it was always choking at WOT. I now know that it was (probably) rich.

I'm on the fence about getting rid of this thing. Seems like too much of a pain to worry about all this esoteric crap just to ride to grandmas house once in a while. I'm looking at another $500 just to get the thing to be comfortable and practical to ride down gravel roads and hit some single/double track once in awhile (I'm a novice dirt rider). Kouba links, RB head mod, headlight that isn't a freaking joke, speedo that actually works (the speedo doesn't work), jet kit (more screwing with and less riding), and decrease the exhaust noise somehow... probably hack on another header or something. Did I mention that the header cracked in half while riding down the road? It handles pretty good but.. can't tell if it's really worth it at this point. If anyone has a KDX or a KTM with plates I will trade straight up. I have lots of other crap to work on. I do have the original seat, which is fucking TERRIBLE. Sends all engine vibrations DIRECTLY TO RECTUM, which is the only thing that is perched on the tip top of the hardon foam peak.. This is not an enduro... it's a motocross bike with plates, the suspension is stiff. I'm 170 and it's too stiff (and high). Which is really cool and obnoxious, but...

Anyway, I'll take $1800 for it. Otherwise I really appreciate any advice anyone could share! Thanks a lot and remember to donate to the forum 111

 

[SwampGasser]

170 main jet, 180 is rich on all Gassers. 35 pilot is good, needle best in #2 position. if that does not fix it, I will give you a grand for it.

 

[Capz85]

N1EF needle is a piece of crap, there are plenty of other good needles to choose from, cheap and easy fix

 

[bob sagass]

Thanks for the replies.

Choosing the needle is another overwhelming headache I think that's why I haven't bought one.

 

[cbutler]

What is "four-stroking"
Try a DDK, CCK
The 300 should be more of a Tractor not a race car. you have to realize you bought some one else's motorcycle set up for them you're going to have to do what you need to do to make it your bike

 

[jhendr3702]

What is "four-stroking"
Try a DDK, CCK
The 300 should be more of a Tractor not a race car. you have to realize you bought some one else's motorcycle set up for them you're going to have to do what you need to do to make it your bike

agree... cck ddk works in those bikes..

 

[(F5)]

The stock needle is so thin at the top big wet fuel droplets sneak past making it run badly and the pilot cct which should be doing the fine spray work is redundant. Several Years wear on the carb won't be helping matters but so be it.

Change the needle. Then the pilot cct can start making a difference. You may actually have to go up a size but depends .

Also clean the carb and read about setting the float height.

 

[bob sagass]

Just for the record I have not done the RB squish correction.

cbutler: I was under the impression that four-stroking was when the engine only fires every other stroke due to it being too rich.
F5: Great info. I think that explains what is happening.

Carb is clean, float height has been set with fuel in the carb. As it sits now the fuel level is a mm or two above the float bowl gasket, which is where I have been getting the smoothest results.

170 main on order with a needle that I haven't picked yet and if that doesn't work I'll check the float again. Another thing is that it's winter now and it was literally freezing here when I took the bike out yesterday so that verifies that it was rich before.

I would like a needle to INCREASE fuel mileage. I'm not worried about shitloads of power on the pipe right now. I'm just trying to learn how to wheelie and the slightly erratic bottom end is making it a little dangerous. And WOT has to be perfectly smooth because I need to blast down the highway to get to any riding area besides my small backyard.

Looking at needle chart now.. thanks a ton

 

[bob sagass]

What is "four-stroking"
Try a DDK, CCK
The 300 should be more of a Tractor not a race car. you have to realize you bought some one else's motorcycle set up for them you're going to have to do what you need to do to make it your bike

I'm pretty sure it was raced a couple times and then sold to the PO, who didn't ride it more than three times. It had a number on it when I got it, but everything seemed damn near brand new (nothing fell off until I started casually riding it) and the "computer" said 40 hours, although I'm not sure it worked the entire time the bike was running.

 

[Zephyr]

Just a thought, but it might be a good idea to throw a fresh float valve in the carb. I've seen ones start leaking in less than a years time, viton tipped ones seem to last the longest. Could be the reason you're overflowing fuel and running a bit rich.

 

[Harry]

HI Bob,

It looks the same as my bike, which is a 2002 EC300.

I am happy with the following jetting at 500m elevation and 10-25 deg.C temp.

pilot- 40
needle- N3EG clip 2 or 3 from the top (Yamaha / Ktm needle)
main - 178 / 175
slide -7

Like all bikes it will take some time and effort to set it up to your needs.

 

[stay_upright]

On my 05 300 what I found to reduce the 4 stroking was a #9 slide with a 35 pilot. The pilot on its own was not enough as it only adjusts a certain range. The #9 slide is whats fitted for hollmologation (at least in the uk) so dealers have them and i got mine free as they fit the 'racing' #7 slide when new and normally chuck the #9 in the bin. It may also be worth noting if your needle valve is worn you may need a needle with much bigger diameter shaft to compensate and get the jetting near correct.

Sent from my EVA-L09 using Tapatalk

 

[risk74]

A few answers to your post:

1. "I'm new to two-strokes. And I probably should have bought a different bike"

That's obvious if you think that thing is ever going to run right without the airbox side cover on. And yes, you should have bought a different bike.

2. Another thing is the air box. I don't really see anywhere where the freaking air is supposed to go in.

The airbox works exactly like it is designed to. If the bike does not run properly, there is another problem somewhere. You are not smarter than the engineers that designed the airbox, re-engineering it is not a solution.

3. Wit pissed fuel on the sidestand, which I removed. What a freaking joke.

So instead of fixing the fuel leak problem, you removed the sidestand? Yes, that does sound like a joke.

4. esoteric crap just to ride to grandmas house once in a while. This is not an enduro... it's a motocross bike with plates,

You sir, could not be more wrong. I ride and race more woods hours in a month on a 2004 Gas Gas EC300 than you ride in a year, have won races with said bike against modern machines. The thing is dead nuts reliable (as reliable as my KDX200). You have obviously inherited someone else's poorly maintained pile. The greatest machine in the world is only as good as the owner who takes care of it. If you decide to save it, (which I imagine you will not) it might just cost more money than it is worth to bring back into stock, reasonable mechanical condition. This is not due to the "esoteric" nature of the machine, but ham-fisted mechanics who have no clue what they are doing.

Good luck.

Kris Larrivee

 

[Jim Cook]

The air comes into the air box through the "handholds" cutouts in the side number plates.