Gas Gas ec 2006 1st gear problems
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My current jetting specs are:
My settings:
Pilot: 42
Main: 180
Needle: #3
Needle type is "N3EG"
My elevation at home is 55ft, Elevation at riding spot is 700 - 1100, I wonder if I went and tried the bike now at 55ft if it would work just as good as before and my spluttering issues are down to the huge change in elevation?
Let's think foward as if the bike does run okay at home (55ft) and runs like crap at 700+, what should I change with my jetting to fix it?
My settings:
Pilot: 42
Main: 180
Needle: #3
Needle type is "N3EG"
My elevation at home is 55ft, Elevation at riding spot is 700 - 1100, I wonder if I went and tried the bike now at 55ft if it would work just as good as before and my spluttering issues are down to the huge change in elevation?
Let's think foward as if the bike does run okay at home (55ft) and runs like crap at 700+, what should I change with my jetting to fix it?
When my powervalve went on the last ride I checked the jet as the first thing and it was nice and tight and it doesn't feel like before, it has some top end meaning the main jet is there and doing it's job I think?
What do you think about the video I posted of the back and forth powervalve play? is that normal?
Could you hear what was happening in the video I posted of me riding? The way the power was perfect right up until top end and then it was just flat and boggy.
It's kind of hard to make out what's happening in that video, because I can't feel the tension myself. Is that all the further it will move? If so, that's a problem.. but here's the deal, you don't want to push it all the way open or you can drop some balls into your transmission.
It should rotate full open by hand though, and it doesn't take much to do it. I think this test is safe to perform if the bike is laying on its side, but I'd verify that before you have to take the RHS cover off to retrieve some balls..
Balls.
Anyway, honestly can't hear a whole lot in that video.. Try messing with the needle and see if it changes!
It should rotate full open by hand though, and it doesn't take much to do it. I think this test is safe to perform if the bike is laying on its side, but I'd verify that before you have to take the RHS cover off to retrieve some balls..
Balls.
Anyway, honestly can't hear a whole lot in that video.. Try messing with the needle and see if it changes!
barossi73
Gold Level Site Supporter
The pv can be viewed with bike running.remove pipe,remove rh cover,refit pipe.start engine and watch operation of pv.
●Im not familiar with that needle,but id probably try a 178 main if its right at the topend you are having a problem.worth trying clip#2 also.(1change at a time)
As the bike gets fully warm it needs a slightly leaner mix.your problem suggests its slightly rich.ie starts fine,runs fine,then falls flat when fully warm.does the bike run fine once its had a rest again?if yes it would confirm,if no something else
●Rereading your post i noticed you thought it was lean
If you are quite sure its too lean go richer on clip/main to confirm
●Im not familiar with that needle,but id probably try a 178 main if its right at the topend you are having a problem.worth trying clip#2 also.(1change at a time)
As the bike gets fully warm it needs a slightly leaner mix.your problem suggests its slightly rich.ie starts fine,runs fine,then falls flat when fully warm.does the bike run fine once its had a rest again?if yes it would confirm,if no something else
●Rereading your post i noticed you thought it was lean
If you are quite sure its too lean go richer on clip/main to confirm
I ran the bike with the covers off and it was opening all the way, I wasn't referring to that part of the PV I was more worried about later in the video where I was pulling on the rod and it was coming towards me and then pushing back in, like in and out play. Is it normal?
Also yeah it did seem to be OK while I first got on it but it's kinda hard to know because I tend to stay away from the powerband until I feel the bike is warm first. I noticed the bike changed if I turned off the fuel and would run a bit better almost like it was possibly over fueling.
Would you go 178 main or #2 clip on needle first if it was your bike? 178 jet seems a lot easier to do lol.
Also regarding it being rich I think you may be right as today I started it straight away with first kick without choke, I heard that means the bike is rich and usually it should require some help from the choke? Although it was around 18c (62f don't know if that matters)
Also yeah it did seem to be OK while I first got on it but it's kinda hard to know because I tend to stay away from the powerband until I feel the bike is warm first. I noticed the bike changed if I turned off the fuel and would run a bit better almost like it was possibly over fueling.
Would you go 178 main or #2 clip on needle first if it was your bike? 178 jet seems a lot easier to do lol.
Also regarding it being rich I think you may be right as today I started it straight away with first kick without choke, I heard that means the bike is rich and usually it should require some help from the choke? Although it was around 18c (62f don't know if that matters)
Which way do I go to become richer sorry? Is it a smaller main & a smaller notch? (180 > 178, #3 clip > #2) ?
barossi73
Gold Level Site Supporter
Cold starting is your pilot jet,ignore for now,it will have no effect on your topend.
If the topend feels smooth flat its prob lean,if its burbly flat its prob rich.very hard to tell from a flyby vid.if in doubt go rich on main/clip first,its safer and will confirm which direction to take.
Bigger jet no is richer,clip 1 (top of needle)is leanest,clip 5 is richest
If the topend feels smooth flat its prob lean,if its burbly flat its prob rich.very hard to tell from a flyby vid.if in doubt go rich on main/clip first,its safer and will confirm which direction to take.
Bigger jet no is richer,clip 1 (top of needle)is leanest,clip 5 is richest
Alright so tomorrow I will take the bike out again, it will probably have the same problems (wouldn't surprised me if it magicly fixed itself though
)It's not massively bad but at the same time it ruins a ride so I think one small change will fix it. The thing I struggle with though is I don't actually know exactly what does what so I find myself testing so much stupid stuff and I don't really know whats doing what, any chance you could make a detailed list of how I should go about testing?
Example:
Step 1 - drop from 180 main to 178
If it improves but doesn't completely fix it go from #3 clip to #4
If it doesn't improve it then go #2 on needle
Or something like the above, it would be super helpful
Bigger numbers = richer. Even with clip positions.
I bet you see improvement with the needle on #4.. Do that first.
You're kind of on the right track, but I would change the main only after bumping the needle up and down first. If #4 improves it, then your bike wants to be a bit richer.. then I would recommend a 182 and 185 to see if it further improves. That seems very rich to me, though.
I bet you see improvement with the needle on #4.. Do that first.
You're kind of on the right track, but I would change the main only after bumping the needle up and down first. If #4 improves it, then your bike wants to be a bit richer.. then I would recommend a 182 and 185 to see if it further improves. That seems very rich to me, though.
Jakobi
Super Moderator
You won't jet around a mechanical condition.. so besides the info you've been given I have a few questions.
When you rebuilt it did you put the same base gasket stack in? Where was the piston in relation to the floor of the exhaust port? Did the piston arrow point towards the exhaust? Ring ends gapped?
What was the squish clearance? If you've changed the base stack and increased compression and decreased squish you can end up tuning the bike to favour low to mid and the top end while revving through won't be producing an impressive peak HP. The curve can be tuned, and by nature a 300 isn't going to feel as peaky as a 250.
Did you remember to put the o-ring on the rhs of the crank case, behind the bushing that the pri seal rides on? Could be pulling some gear oil at higher rpm.
As others have said, rich will stop revving in that it will break up and burble.. lean will make noise but won't pull and fall flat.
When you rebuilt it did you put the same base gasket stack in? Where was the piston in relation to the floor of the exhaust port? Did the piston arrow point towards the exhaust? Ring ends gapped?
What was the squish clearance? If you've changed the base stack and increased compression and decreased squish you can end up tuning the bike to favour low to mid and the top end while revving through won't be producing an impressive peak HP. The curve can be tuned, and by nature a 300 isn't going to feel as peaky as a 250.
Did you remember to put the o-ring on the rhs of the crank case, behind the bushing that the pri seal rides on? Could be pulling some gear oil at higher rpm.
As others have said, rich will stop revving in that it will break up and burble.. lean will make noise but won't pull and fall flat.
barossi73
Gold Level Site Supporter
This is what i would try-
Step1-ride it how it is again to confirm it runs well initially and that as it warms the problem appears.if yes...
Step2-try clip4 (1 step richer)if worse try clip2
Pay attention to 1/4 to 3/4 throttle,not just top end.
Decide which clip no feels best overall and run with that.
Step3-try a richer main jet (in case u are lean on top)if no improvement...
Step 4-try a leaner main jet
These steps will give you a feel for what is rich/lean and what effect each change has.only change 1 thing at a time.
Point to remember-a too rich engine will run badly only,a too lean engine will destroy itself,which is why its better to try richer first!
Step1-ride it how it is again to confirm it runs well initially and that as it warms the problem appears.if yes...
Step2-try clip4 (1 step richer)if worse try clip2
Pay attention to 1/4 to 3/4 throttle,not just top end.
Decide which clip no feels best overall and run with that.
Step3-try a richer main jet (in case u are lean on top)if no improvement...
Step 4-try a leaner main jet
These steps will give you a feel for what is rich/lean and what effect each change has.only change 1 thing at a time.
Point to remember-a too rich engine will run badly only,a too lean engine will destroy itself,which is why its better to try richer first!
The reason I don't think it's mechanical is because it was running really nice for approx 15minutes before powervalve issue then after I had the plate welded it ran really nice again, I had a good 10 minute run on road where I used every gear 1-6 and all in the powerband too and it ran perfect.
barossi73
Gold Level Site Supporter
Pilot jet 0-1/4 throttle
Needle 1/4 to 3/4
Main 3/4 to full
There is some overlap however
Rich engine tends to blubber/splutter(as if choke is part on)
Lean engine feels thin/tinny,breathless,runs hotter.when throttle is cracked open tone changes and makes a bwooar sound.idle may hang high for a second or two before dropping down.under long deceleration with throttle closed can hear constant ring ding ding from pipe
Needle 1/4 to 3/4
Main 3/4 to full
There is some overlap however
Rich engine tends to blubber/splutter(as if choke is part on)
Lean engine feels thin/tinny,breathless,runs hotter.when throttle is cracked open tone changes and makes a bwooar sound.idle may hang high for a second or two before dropping down.under long deceleration with throttle closed can hear constant ring ding ding from pipe
Wishing I put the camera back into my helmet to get a better idea of what was going on. Part of me thinks it's something to do with the powervalve because I had a previous problem with jetting when the bike came to me with a 172 main and the worst needle possible so I'm familiar with jetting problems but the bike runs great right up until I get into the powerband, it gives me a taster and just falls off.
If I don't get it fixed tomorrow with jetting I will be sure to get some videos of the camera on my helmet so you get a better idea of how it's running.
Also I have just watched over the video I posted: https://www.youtube.com/watch?v=GL2rfbq4Pbk
Put some headphones on and put them to max volume so you can really hear whats happening, at the very start you hear me pulling off in first, I shift once or twice and then full throttle it and at around 4/5sec you can hear the problem I'm having. It definitely sounds lean I think.
Also around the 0:07-0:08 mark as it passes you can tell it has no guts, it's WOT there.
At around 1:03 that is WOT gear 4 then I shift down to try and give you a better idea of the sound and you can tell the power is there for like 60% but powerband just wasn't kicking in, it fell flat.
At around 1:18 you can hear as I'm turning around the powerband kicks in slightly, the raspiness of the powerband is quite clear but you quickly hear it fall off.
If I don't get it fixed tomorrow with jetting I will be sure to get some videos of the camera on my helmet so you get a better idea of how it's running.
Also I have just watched over the video I posted: https://www.youtube.com/watch?v=GL2rfbq4Pbk
Put some headphones on and put them to max volume so you can really hear whats happening, at the very start you hear me pulling off in first, I shift once or twice and then full throttle it and at around 4/5sec you can hear the problem I'm having. It definitely sounds lean I think.
Also around the 0:07-0:08 mark as it passes you can tell it has no guts, it's WOT there.
At around 1:03 that is WOT gear 4 then I shift down to try and give you a better idea of the sound and you can tell the power is there for like 60% but powerband just wasn't kicking in, it fell flat.
At around 1:18 you can hear as I'm turning around the powerband kicks in slightly, the raspiness of the powerband is quite clear but you quickly hear it fall off.
Jakobi
Super Moderator
So it should simply be a matter of determining what has changed between then and now.
The in and out play on the PV drum is somewhat normal. I doubt that is causing your issues unless if it's binding something up as it opens, but you said you ran the engine with the PV cover off and watched it open with rpm.
Have you had the PV flapper/drums out again while having it rewelded. Double checked it's assembled correctly? Didn't leave anything stuffed in an exhaust port/pipe while it was off the bike?
Do you run an inline filter between the tank and carb? Double check your main jet. It doesn't take much to block it up (or severely restrict its flow).
What's the spark plug tell you? This is one of the times you could do a pull chop at WOT and see if the engine is over/under fuelling. A new plug gapped and installed wouldn't hurt either. Particularly if it's been changed between when it ran strong and now doesn't.
This girls playing hard to get on ya for sure! Hang in there mate!
I actually changed the plug after 5 minutes of having the problem as I did an oil change before this happened and let the bike idle for quite a while to warm it up ready to drain and I thought maybe it had filled the plug with oil, no difference.
PV assembly looks good, I had it off and was revving the bike and saw it open nicely and stays open at certain RPM and slowly closes ect, all seemed ok from what I could see. I will give the main jet a quick clean tomorrow too although I thought with the time I was trying to get it to run right by adjusting air screw ect it would of cleared itself out but I'm willing to give everything a try!
