Jetting Verdict

[Jakobi]

Its too lean.

You can hear it in your first video when you open the throttle. It gasps for air instead of cracking to life.

Take the clip back to position 2, if not 3. Then drop the idle speed right down. Don't worry about getting the bike to idle on the stand. Use the air screw to get the bike to respond off the bottom how you want, and then finally tweak the idle speed so it just ticks over.

You can also use some tape and a marker on your throttle body and grip and index closed, WOT and a few points in between to help. The bike won't have that huge blasty hit when you open the throttle like it used to. That was a rich to lean transition. It should pull strong and smooth. Too lean and it will feel crisp, but kind of sound like its going faster without doing too much in the way of pulling.

 

[Buysomerice]

Excellent, will be nice to put my bikes sound to a symptom. I'll do everything you said next go around. I'll just carry a screwdriver with me and tweak for feel and forget my idle complex lol. That blasty hit explanation is golden advise, I will keep that in mind. Thank you yet again.

 

[Jakobi]

And if you haven't set your float height yet, thats not a bad thing to look up and check either. Everything works around it.

 

[Buysomerice]

True, I've been assuming it's on since it's fairly new. Definatly will check that.

 

[liv2day]

Its too lean.

You can hear it in your first video when you open the throttle. It gasps for air instead of cracking to life.

Buy - thanks for posting those videos - being a newb to the jetting stuff myself, it's great to hear your bike and then read the analysis.

Jake - let me ask a (possibly stupid) question. If that first video highlights a lean condition, wouldn't it be starved for fuel instead of air? I thought a lean condition meant there was too much air and not enough fuel, and that's what leads to higher running temps and potential engine issues?

Listening to that video makes me think I might be lean on my 200. Any chance you can post a similar video of your bike Jake so we could "see" the differences?

 

[gasmonkey]

Jake has plenty of vids on here doing the brapbrap thing.Look in the aussie section.

 

[Jakobi]

Heres a video from Slavens - https://www.youtube.com/watch?v=zVzqqpgviyI - I don't agree with everything he says all the time, but with this its good advice.

Liv, you are right, its not actually gasping for air, but it sounds like its gasping. A cold engine will always do this a bit. When running well and up to temp it should just take the throttle.

Heres another video that shows what a lean condition sounds like. https://www.youtube.com/watch?v=0AKXLEmAVEs

Now to confuse you more. Those 2 videos show that this can happen at any point in the throttle range. In buymores video I would say its likely running in clip 1 and opening into that 1/4-1/2 throttle range that was causing the slight lean sound, and the flat/weak power curve. The FCR carbs on the 4 strokes use a fuel pump/AP squirt to boost the fuel required when cracking open hard.

 

[Jakobi]

Further to that, make sure the bike is up to temp and cleared out before testing yours and thinking its wrong. I don't know if buymore had just put the needle in when he recorded that. When you open the throttle you should get a nice smooth rise in revs, followed by them dropping back down into the idle again.

Lean will like gasp a bit and may hang above idle for a bit before returning, where as rich will just sound wet and blubbery and be more inclined to load up and flame out instead of idling.

I'll try and get some video of my bike next time I have it up to temp.

 

[Buysomerice]

Liv-No problem, yours threads have helped me in return on things.

Jak-The first vid was indeed the needle in the first clip. It was cleared out and warm because that was actually the last vid of the day, after the other two. Come to think about it, on the way home at the last stop it did hang a bit. I forgot that bit because I didnt know how it was hanging being rich, when in fact it was lean.

I only leaned it out because I was doing the slight uphill 3rd gear thottle opening and the low clips all felt jerky and lacked power. This could be from being concerned with idle and not tweaking the airscrew for performance (which I didnt know it did at the time) or starting to low in 3rd?? I start very slow with the throttle barely pushing the bike. Is that correct?

 

[Jakobi]

I just lightly warmed my bike up after you blokes got me thinking. Not up to full running temp but rads warm. Responds pretty well off the bottom but I think I could go up a size on the main. I also had a fresh air filter and the seat off which would have it running a bit leaner than normal too.

What do you mean by jerky? In 3rd gear at walking pace really you should be able to roll on the throttle and have the engine cleanly pull through. Obviously its not going to throw you back at idle in 3rd either. I've done loads of jetting up and down the street, and imo it doesn't really cross over to how the bike feels and reacts in the dirt. Best advice is to spend a day in the bush and try a few different things so you can experience what feels best.

 

[Buysomerice]

Yeah that is what I did. My vids are all from the way home from the testing grounds! I was just thinking she would still roost a little bit, maybe I was asking to much? Should I just be looking for consistent pull? By jerky I mean that engine clunking that you can feel down low like chugging.

 

[liv2day]

Heres another video that shows what a lean condition sounds like. https://www.youtube.com/watch?v=0AKXLEmAVEs

Wow, that's really interesting/informative! After he clears the engine, it really goes "flat" when he goes WOT. I've never heard that on any of the bikes, so I'll take that as a slight positive

Thanks for posting that Jake, I'm going to take a listen to the Slaven's video too and my guess is it'll just add to the knowledge.

 

[Jakobi]

I started my bike with a 172 main, N3EW#2 and 40 pilot and had it gasp like that. Ended up changing the needle to a NEDW#2 (which has a thinner tip - richer towards WOT) and it runs well. I still think its a touch lean as we come into the cooler months.

When I set my pilot circuit up it usually has a very slight hesitation, and thats the price I pay for somewhat clean jetting off the bottom. In saying that, its not often I go for a ride and don't make an air screw adjustment to get the balance between clean and responsive the way that I want it.

 

[Buysomerice]

Hello all once again. Little update.

So I got the bike to a happy place with a 40p, nedj 3rd(mid), 178main. Feels pretty smooth and got rid of a flat top end goin up from 175 main.

All was good till I did some heavy riding and noticed the bike was lacking major power/no grunt on steep hill climbs. It behaved like a small cc bike had to keep revs up or it felt very underpowered/died. This is my favorite riding so I just want to get it hammered out better.

Checked the plug, tip is tan but the base is a little on the gray side. Exhaust still drools also.

Removed carb and found I have a 65 on my slide. I'm assuming that is a 6.5 slide I have read about. Also double checked that it is a 38mm, read some came diffrent.

I also cecked the float level they are dead parallel with the mating surface. Cheap set of calipers is putting it in the 7mm range or pretty close.

Also added a in line fuel filter for that ride. Installed the correct way.

So I know that slide changes the game from the typical jetting of the 7 slide, but how? Is the fuel filter affecting the hill climb power? Or is just a lean/rich condition? Is this how the nedj acts under heavy load?

I'm learning lots so again thats for the read/input.

P.s.Did this on my phone will proof read later sry.

 

[Buysomerice]

Floats with needle seated/first contact.

 

[liv2day]

All was good till I did some heavy riding and noticed the bike was lacking major power/no grunt on steep hill climbs. It behaved like a small cc bike had to keep revs up or it felt very underpowered/died. This is my favorite riding so I just want to get it hammered out better.

Ok, what's with bagging on the small CC bike - 200s rock..LOL. Only kidding

My first question would be where you have the idle screw and a/s combination set. It could be as simple as turning your a/s out a bit to lean things out. If I understand correctly, the 6.5 slide will make life a bit richer (compared to the 7), so if the a/s doesn't resolve the issue, it might be worth throwing in a 38pj too.

All that said, what did the lack of power feel like? Was it a burble, or did it feel like a lean bog?

Hopefully, Jake will chime in with some advice as well since I'm in the same learning boat you are.

 

[Buysomerice]

She just better feel like she lost of few pounds if she is going to dance like a 200! Oh my, so wrong.

Airscrew is 1.5 out. Idle screw Is 8.5mm from carb to base of screw head (sorry I dont know how to measure that setting). The idle was slow that day and did stall out with clutch in once or twice. She went through the gears on level ground good though.

The bog felt like what I think is lean bog in that I could bounce the throttle on a hill once I lost the power and it would just moan not put the power down.

I just wanna make sure this needle can get me where I want in grunting up the hills before I fiddle to much. Or if that sounds like a specific jet issue, I thinking about richening the needle. Just getting some input before I start trial and error again.

 

[Jakobi]

You've got a few odd balls there.

Whats your temp and elevation at the moment?

The 6.5 slide might be a bit rich on the 300, but it is also notched which will allow more air to pass under it, especially at lower openings.

The description you advised does sound like its a bit lean still, but you will find that its a delicate balance. I find with ideal jetting you do need to be a bit more on with the gear changes and use the lower rpm for smooth application, and the meat of the power to ride hard. Alternatively, a richer more blubbery setup will grunt and torque better and actually prefers to be ridden a gear high and the engine load will smooth the burble out some too. A bit of personal preference definitely comes into it.

What throttle position is it feeling like its a bit dull? Consider indexing the throttle with some tape and a pen so you can drill down and find the exact position, which will help confirm which circuit you are working in.

I like the floats more around 8mm (not level), which reduces the splashover when bouncing around and especially on down hills.

 

[Buysomerice]

Good to know about the slide, that notch had me wondering.

The temp that day was 80*f +- with probably 50% humidity. I have the throttle indexed and it was bogging on anything above halfish hard to say exact because it was gnarly climb. Had to go low down and slip the clutch to make it.

So my style definatly favors rich, I always rode a gear high and lugged. My style is why spin the tire and loose traction with rpm's if I dont have to. Since it's also "safer" to go that way is why I think I'll go that direction till its noticbly worse or starts getting better. I never felt anything was that off with my stock setup other than being told it sounds rich and spooge, so worst case I may go back to that and lean it up abit for summer. Definatly glad I'm learning this though.

 

[Jakobi]

Think about it as if it were a car and an incline. Fuel injected, perfect AF ratio. Sometimes the gear is just too tall for the hill you are climbing, and adding throttle might keep it chugging but you'll be hard pressed to make it pull until you knock it back a gear.

The bike is the same, except slipping the clutch just allows you to avoid the downshift at times.

Again, it really depends on the extent of the hill and the gear you were hitting it in as well as the gearing on the bike.

By half throttle you're well into the meat of the needle. Clip position is the big one here. You may be able to aim the helmet cam at the throttle for a more accurate idea of whats happening there when climbing and focussing more on getting to the top.