ViperTom
New member
Aaen pipes w/Heavy Hitters....sometimes it pulls 9100 and runs great....other times its only pulls 8800 and runs not so great. I havn't installed a torque limiter yet, could it be binding? Any thoughts?
I also get the DCS light flashing once in a while when at 1/2 throttle...has anyone else encountered this? My jetting looks good when I check the plugs...if anything I'm running a bit rich.
Tom
I also get the DCS light flashing once in a while when at 1/2 throttle...has anyone else encountered this? My jetting looks good when I check the plugs...if anything I'm running a bit rich.
Tom
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when your cruising at half throttle, your on your needles, did you ever check the plugs/piston wash after a long cruise on the needles and just shut it off and pull the plugs and take a peak at the pistons? I bet your lean on your needles, this is common and usually you need to bump the pilot up, fuel screws some , and then just barely raise the needles, because the pilot circuit overlaps the needles and you can compensate with both and come up with a better result then just raising the clip. With just the clip only you can get overly rich and the motor blubbers at cruising. Also, is the temp the same when the sled acts up or only certain days? whats your jetting set up now?
ViperTom
New member
temps have been from 15-25 degrees. Carb settings are currently stock pilots and fuel screw settings, needle at 3.5 on the pto and 4 at the center and mag, 162.5 main on the pto and 165 center and mag. I will check the plugs midrange again just to be sure but they looked dark brown last time I looked. I had the fuel screws at 2 1/8 but every time I would start it I would foul plugs so I turned them back to 1 7/8 and never fouled another one.
Tom
Tom
yamiman
New member
did you check your front left motor mount, when i cpr pipes mine broke and sometimes i was okay with the rpm other times it was a lot less.
..SNAKEBIT..
VIP Member
sounds like we have similier running conditions
Viper with CPR pipes, head mod, atacc, etc.....
I ride flat land like Iowa and also go out west with it was wondering where any of you were at with the carbs
holtman Atacc installed like rev*baron's in tech
jets 165 165 170
pilots 47.5 47.5 47.5
needles 3.5 3.5 4
screws 2 2 2.25
seems real blubbery till @ 6500-7000 then it takes off and runs some times it will only pull 8500-8700 rpm thinking its shifting out to fast and wont back shift BUT I think I need to fine tune the carbs closer first so the power is right
8dn-10 weights
50-40 with green spring @ 70'
this was on my first ride saturday Dec 10th
need to check plugs and wash monday at shop, but was sitting at home wondering what other people ran, and where I should start? mains, pilots, needles, or clutching????
thanks for any input Marty
ps have checked wash and exhaust side of pistons are clean at the exhaust port @ 1/2" in from edge and @ 1/3 around edge (like a big smile)
Viper with CPR pipes, head mod, atacc, etc.....
I ride flat land like Iowa and also go out west with it was wondering where any of you were at with the carbs
holtman Atacc installed like rev*baron's in tech
jets 165 165 170
pilots 47.5 47.5 47.5
needles 3.5 3.5 4
screws 2 2 2.25
seems real blubbery till @ 6500-7000 then it takes off and runs some times it will only pull 8500-8700 rpm thinking its shifting out to fast and wont back shift BUT I think I need to fine tune the carbs closer first so the power is right
8dn-10 weights
50-40 with green spring @ 70'
this was on my first ride saturday Dec 10th
need to check plugs and wash monday at shop, but was sitting at home wondering what other people ran, and where I should start? mains, pilots, needles, or clutching????
thanks for any input Marty
ps have checked wash and exhaust side of pistons are clean at the exhaust port @ 1/2" in from edge and @ 1/3 around edge (like a big smile)
try this
take a small maglite with you and peek at the pistons on your mid range check, see if they are all dry or wet around the edges. run the sled somewhere for a good 700ft long on the midrange, hit the kill switch and take a look
Also if you have the needles up at 4 on the center and mag, do you have both washers under the clip or 1 on each side of the clip?
I have found sometimes your better off to use the next size up in pilot jet and then set your screws at about 1.5 turns out, this will allow you to run a slightly leaner needle setting and improve the response from the engine, it will eliminate the blubbering, low rpm situation
take a small maglite with you and peek at the pistons on your mid range check, see if they are all dry or wet around the edges. run the sled somewhere for a good 700ft long on the midrange, hit the kill switch and take a look
Also if you have the needles up at 4 on the center and mag, do you have both washers under the clip or 1 on each side of the clip?
I have found sometimes your better off to use the next size up in pilot jet and then set your screws at about 1.5 turns out, this will allow you to run a slightly leaner needle setting and improve the response from the engine, it will eliminate the blubbering, low rpm situation
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ViperTom
New member
I check the motor mounts and they seem Ok. I ran through all my jetting and it appears I am still a bit lean. Would lean jetting cause my RPM's to be inconstistant? I checked low, mid and WOT on the jetting and here are the results. Also..The temp was 26 degrees and the tach was reading 9100 at WOT (ran great). I looked at the pistons when I pulled the plugs and they seamed dry.
Thanks for all the help guys,
Tom
Thanks for all the help guys,
Tom
Attachments
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skidooboy
New member
don, not stepping on your toes but i noticed above tom is only running stock pilots (45) on his aaeen pipes. i am guessing he is lean there and should start at 47.5's (bushman could help him out on a jetting set up as he runs aaeens) i am wondering if he has a clutching issue or just a snow condition thing that is giving him inconsistant rpm's. heavy wet snow and light powdery snow will give different loads on the cvt. he may have a roller or bushing or secondary issue causing the rpm fluctuations as well. i think if we had more info on the runs temps, snow how far the run was ect... we may be able to shed more light on the rpm problems. tom plug pics are ok but alittle hard to read still. it would be better to show from above the electrode looking into the insulator. don has given you some very good info up there if you give us alittle more i am sure TY can fix ya up. ski
viper
Eric ,if you stepped on my toes, I would say OUCH....lol!!
I thought he may need to richen up the pilot circuit some, fuel screws and then very slightly, move the shims around on the needles. To get the midrange to fall into place and not have to have the clips up real high.
Ok, if all the mounts and clutch stuff are ok we should try to dial in the jetting a bit better, a lean condition can cause rpm problems, its gonna have alot to do with motor temp, air density, air temp. A warmer motor is richer, and vice versa, so if it was say 15 degrees out and low air density, a sled would not pull rpm,(if it was lean) there isnt enuff fuel there to allow it to.
The great thing about these yamaha's is when they are too lean, they usually just kinda nose over, and they dont squeek as easy as other brands, thats to say within reason now..lol.
Tom, did ya peek at the pistons evrytime ya checked the plugs too? I unfortunately cant see the plugs good enuff in the pics to see whats going on.
Like Eric said, maybe Randy could give ya a baseline to start from and then you could dial it in to your paticular application.
Eric ,if you stepped on my toes, I would say OUCH....lol!!
I thought he may need to richen up the pilot circuit some, fuel screws and then very slightly, move the shims around on the needles. To get the midrange to fall into place and not have to have the clips up real high.
Ok, if all the mounts and clutch stuff are ok we should try to dial in the jetting a bit better, a lean condition can cause rpm problems, its gonna have alot to do with motor temp, air density, air temp. A warmer motor is richer, and vice versa, so if it was say 15 degrees out and low air density, a sled would not pull rpm,(if it was lean) there isnt enuff fuel there to allow it to.
The great thing about these yamaha's is when they are too lean, they usually just kinda nose over, and they dont squeek as easy as other brands, thats to say within reason now..lol.
Tom, did ya peek at the pistons evrytime ya checked the plugs too? I unfortunately cant see the plugs good enuff in the pics to see whats going on.
Like Eric said, maybe Randy could give ya a baseline to start from and then you could dial it in to your paticular application.
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Mtnviper
Member
Another possibilty could be, that it may be running rich from sucking hot under hood air into the air box. Piped Viper's do have more underhood heat from the pipes, it's more noticeable when the vent's are plugged with snow.
I found mine to run much more consistant, when I added some flowrites. I left the under hood intake open so it would suck in some warm air under the hood, to mix with the cold air through the flowrites. Jetting/rpm's are more consistant now, when the ambient temp's change. Just a thought.
I found mine to run much more consistant, when I added some flowrites. I left the under hood intake open so it would suck in some warm air under the hood, to mix with the cold air through the flowrites. Jetting/rpm's are more consistant now, when the ambient temp's change. Just a thought.
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ViperTom
New member
When I first start it and get it warmed up it will pull 9100 on the tach. After 5-10 minutes of riding it sometimes will only pull 8800 (on hardpack). Yea, the pics turned out kind of crappy but it appears that I am a bit lean in the center and mag cylinders midrange-WOT. I think I will start with the pilots and go one size up acrossed the board and then take another look at the plugs and go from there.
Temps have been 15-25 degrees and running on hardpack. Today when testing out on the road it did peak out at 9300 RPM's one time with the speedo indicating 135 (hit an icy patch) but other than that 8800-9100.
Tom
Temps have been 15-25 degrees and running on hardpack. Today when testing out on the road it did peak out at 9300 RPM's one time with the speedo indicating 135 (hit an icy patch) but other than that 8800-9100.
Tom