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AnonymousDoes anyone have any experience with their 2 stroke running poorly, spluttering at about 20% throttle and struggling to hit band but ripping when it does and it NOT being the jetting?
Also, what sort of jetting changes have you made when running an aftermarket pipe like an FMF Gnarly? Do you make large jetting changes (I’d be surprised) or just a main and pilot jet?
I’ve got the bike sat at the stock specs and it runs poorly. It has an FMF Gnarly that has a fair leak at the cylinder head and there is black juice all over the pipe.
I’m tending to think the (apparent leak) is effecting the 2 stroke cycle and causing the problem.
I changed the clip up one on the needle (position 2 to position 3) and that made it worse, stalling the bike at the bottom of the hill and I had to puch it back up (mental note: ride the bike UP the hill to test next time
)Fuel and spark appear to be fine.
the next test is to refit stock pipe and see if:
a) this works better with stock jetting
b) It fits better to the head and creates a proper seal eliminating a leak as the cause of the problem.Cheers,
Mo-oh
Moto, there are to many variables at play here. I will just give a few to get the grey matter ticking over. Is this the 200 or the 300 we are talking about?
1. fuel mixture – preferably 40 – 50 to one good quality fresh?
2. Oil semi synthetic or fully synthetic preferably
3. Spark plug dont use the $4 jobs try an EGV
4. oil build up in the pipe and muffler packing may need replacing, oil/carbon may need to be burnt out of the pipe
5.Air filter good?
6. reeds good?
7.HT lead and condenser good?
8.although you have a bit of a leak at the head it wont affect the performance to much. clean out the faces with white spirit and apply a good high temp silicone.
9.timing?
10. float level
11. compression?Thats about all I got
Ollie
Ollie has a heap of good stuff there, but his point number 8 for me I dont think the running will be affected by the joint, idle maybe.
I feel that after all the above that Ollie has put down is down it will be jetting. Small changes one at a time and test and check, another small single change test and check and write it down.
But make sure you cover all basics and keep it simple. If you dont have high temp silicon normal will do the job.
After all that, like we spoke about today take it to fathead and run it on the dyno and let him teach you and see the changes maybe
TB
Anonymous
AnonymousOllie wrote:
Quote:Moto, there are to many variables at play here. I will just give a few to get the grey matter ticking over. Is this the 200 or the 300 we are talking about?1. fuel mixture – preferably 40 – 50 to one good quality fresh?
2. Oil semi synthetic or fully synthetic preferably
3. Spark plug dont use the $4 jobs try an EGV
4. oil build up in the pipe and muffler packing may need replacing, oil/carbon may need to be burnt out of the pipe
5.Air filter good?
6. reeds good?
7.HT lead and condenser good?
8.although you have a bit of a leak at the head it wont affect the performance to much. clean out the faces with white spirit and apply a good high temp silicone.
9.timing?
10. float level
11. compression?Thats about all I got
Ollie
Cheers for the help Ollie, responses as follows:
1. Fuel mixture is 50:1, it runs worse at 40:1. 98 ron fuel and it’s fresh.
2. Motul 800 same as everyone else uses (or seemingly so anyway)
3. I bought 2 decent spark plugs at Louee, 1 grade hotter and it ran better.
4. This may be possible in the pipe, The bike hasn’t had a proper run on the new baffle I put in a few weeks ago.
5. Air filter isn’t brand spankers but is more than adequate.
6. The reeds look okay, what should I be looking for? If they have snapped off?
7. HT lead is assumed to be fine as the spark is good. Condenser?
8. I will try this, I was going to try fitting the stock pipe and see if it seal better also. Having it stock will be a better start point too.
9. Timing of what? Maybe it’s a valve/cam issue :laugh: I assume you mean spark? How do I change that?
10. Float seems to be okay, floats checked and operate fine. Yes the fuel tap is turned on
11. I don’t know how much compression a 200 should have but it seems fine with the old finger over the spark plug hole check. Kicking it over seems fine too, has resistance.It runs well right up at the top of band and off idle, just the rest of it (where normally used) that’s the issue.
Cheers for the help so far guys
AnonymousNot this time, also this is tech help so serious responses only please Trent! It’s the only forum where no banter is allowed
Moto wrote:
Quote:Ollie wrote:Quote:Moto, there are to many variables at play here. I will just give a few to get the grey matter ticking over. Is this the 200 or the 300 we are talking about?1. fuel mixture – preferably 40 – 50 to one good quality fresh?
2. Oil semi synthetic or fully synthetic preferably
3. Spark plug dont use the $4 jobs try an EGV
4. oil build up in the pipe and muffler packing may need replacing, oil/carbon may need to be burnt out of the pipe
5.Air filter good?
6. reeds good?
7.HT lead and condenser good?
8.although you have a bit of a leak at the head it wont affect the performance to much. clean out the faces with white spirit and apply a good high temp silicone.
9.timing?
10. float level
11. compression?Thats about all I got
Ollie
Cheers for the help Ollie, responses as follows:
1. Fuel mixture is 50:1, it runs worse at 40:1. 98 ron fuel and it’s fresh. Good
2. Motul 800 same as everyone else uses (or seemingly so anyway) Good BTW I use Caltex or Mobil @40:1
3. I bought 2 decent spark plugs at Louee, 1 grade hotter and it ran better. Have you done a plug chop?
4. This may be possible in the pipe, The bike hasn’t had a proper run on the new baffle I put in a few weeks ago.
5. Air filter isn’t brand spankers but is more than adequate. presume it is clean?
6. The reeds look okay, what should I be looking for? If they have snapped off? chipped corners or fatigue cracks
7. HT lead is assumed to be fine as the spark is good. Condenser? whoops meant coil resistance readings in spec
8. I will try this, I was going to try fitting the stock pipe and see if it seal better also. Having it stock will be a better start point too.
9. Timing of what? Timing marks on your rotor look it up in your manual or download from the net Maybe it’s a valve/cam issue :laugh: I assume you mean spark? How do I change that?
10. Float seems to be okay, floats checked and operate fine. But are they set at the right height? very important Yes the fuel tap is turned on
11. I don’t know how much compression a 200 should have but it seems fine with the old finger over the spark plug hole check. Kicking it over seems fine too, has resistance. pressure should be about 175 PSI with throttle WOTIt runs well right up at the top of band and off idle, just the rest of it (where normally used) that’s the issue. Probably jetting thinking slide number air screw and needle main sounds fine
Cheers for the help so far guysalso something to check is the pwer valve functioning correctly?
best of luck mate
Olliemo-oh, i was just thnkng that i remember you saying it ude to be raced. if so, im looking towards the jet thig cause being a 200 it might be sets to be pinned most of the time. good for us, no good for cruising.
go get it dyno-d. scott will give you the answer you are seeking and be able to tame it down for tyne if you like with timing and shit.
it will be something trivial i reckon.
..it has compression…tick.
..it has spark…tick, (but check the resistance readngs of the magneto thing like ollie says as they can effect spark in funny ways).
..that only leavs fuel path. as yo would know being you :laugh:
Awww f#@k, just give it to Batman, and save the worry :laugh: :laugh: :laugh:
im drinked enough for twoMoto wrote:
Quote:Ollie wrote:Quote:Moto, there are to many variables at play here. I will just give a few to get the grey matter ticking over. Is this the 200 or the 300 we are talking about?1. fuel mixture – preferably 40 – 50 to one good quality fresh?
2. Oil semi synthetic or fully synthetic preferably
3. Spark plug dont use the $4 jobs try an EGV
4. oil build up in the pipe and muffler packing may need replacing, oil/carbon may need to be burnt out of the pipe
5.Air filter good?
6. reeds good?
7.HT lead and condenser good?
8.although you have a bit of a leak at the head it wont affect the performance to much. clean out the faces with white spirit and apply a good high temp silicone.
9.timing?
10. float level
11. compression?Thats about all I got
Ollie
6. The reeds look okay, what should I be looking for? If they have snapped off?
It runs well right up at the top of band and off idle, just the rest of it (where normally used) that’s the issue.Cheers for the help so far guys
Hold the cage up to the sun, look for light passing through.
Flip them over if there is and give that a try.
Also check your wires connected to the ignition are connected.
AnonymousCheers for the replies. Yes it the 200, the 300 is running sweet
Magneto could be the issue I guess, I’ll get the multimeter out and check.
Reeds could also be the culprit.The engine had a complete rebuild less than 50 K’s ago. It hadn’t been run in when I bought it so I would be upset if the compression is low!
Menace the jetting was bigger to start out with. It had a 190 main but it ran terrible with that too. It’s been returned to standard with the excpetiion of the FMF pipe.
I’m just about to put the needle up 2 clips (I put it down one and it made it much worse) and if that doesn’t work it will be back to where it works best for tomorrow’s ride.
Fathead could be the go in the New Year.
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