Frostbite
TY 4 Stroke God
I rode my RX-1M last week with 160 mains at 3-6,000 feet with the needles in the stock position. I noticed a pretty audible burble in the 5-6,000 RPM range. I ended up towing a buddy back (poor guy) and was at this RPM longer than normal so maybe that's why I felt the need to at least try to remedy the burble.
So, since there is dramatically increased airflow with the ECPs I raised my needles (lowered the clip) one notch to give the midrange a little more fuel to compensate.
Here's my question. I typically associate a "burble" with a too rich condition. If what I was hearing was an indication of a too rich condition then I went the wrong way (richening) with my needles. I rode the sled again yesterday with the needles raised and the burble seemed much less pronounced. Yet, I read on here again and again about people LOWERING their needles (raising their clips) to take care of the burble. Huh?
Can someone straighten this out please? Merry Christmas. PB
So, since there is dramatically increased airflow with the ECPs I raised my needles (lowered the clip) one notch to give the midrange a little more fuel to compensate.
Here's my question. I typically associate a "burble" with a too rich condition. If what I was hearing was an indication of a too rich condition then I went the wrong way (richening) with my needles. I rode the sled again yesterday with the needles raised and the burble seemed much less pronounced. Yet, I read on here again and again about people LOWERING their needles (raising their clips) to take care of the burble. Huh?
Can someone straighten this out please? Merry Christmas. PB
kawman
Veteran
raise the needel lower the clip but im in ny 1200 feet
Buster696
VIP Member
PB,
I do not run at the same elevation as you do, I run around 300ft to 400ft. I have the needle in the stock position and I have tried all of the Holtzman Springs (Red, Green, Yellow, and Silver) with the ECP kit. The Holtzman-Yellow and Holtzman-Silver do not have the problem you are describing. I like the Silver the best (because of power) and 'for now' I'm sticking with them (Silver).
Hope this helps you out...
--Buster696--
I do not run at the same elevation as you do, I run around 300ft to 400ft. I have the needle in the stock position and I have tried all of the Holtzman Springs (Red, Green, Yellow, and Silver) with the ECP kit. The Holtzman-Yellow and Holtzman-Silver do not have the problem you are describing. I like the Silver the best (because of power) and 'for now' I'm sticking with them (Silver).
Hope this helps you out...
--Buster696--
welterracer
TY 4 Stroke God
I ride at 800ft and i have NO burble!! I had a burble with the stock airbox with green springs.. But when i went to the ECP kit and silver springs it went away... When cold it does it but when it warms up it goes away!!
It just doesnt stay in that rpm (6000)long enought to even know its there... Its more of noise then a lag in power or hesitation!!
It just doesnt stay in that rpm (6000)long enought to even know its there... Its more of noise then a lag in power or hesitation!!
Buster696
VIP Member
welt, good to hear... I also noticed that when the motor warms i had less of a burble, (or none at all) whatever spring i tried...
--Buster696--
--Buster696--
Frostbite
TY 4 Stroke God
I have been using the Yellow Holtzman springs. Perhaps the Silver would be a better choice. I bought them before anyone ever heard of the ECP filter kit. The burble isn't anything I couldn't live with by any means. I would LOVE to leave my needles in the stock position to increase the range of my sled by improving the economy.
I still think if I cut a ring or two off the Yellow springs I MAY have a useless set of springs OR ones that work outstanding and are very similar to the silvers?
I still think if I cut a ring or two off the Yellow springs I MAY have a useless set of springs OR ones that work outstanding and are very similar to the silvers?
Pinball Wizzard
Pro
I'm running the silver with 160 's and have a slight burble but hace not had time to play with needles / its not that bad.
Cubby's RX-1
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Dude, get the silver springs and dont cut your yellows.
SUPERTUNER
TY 4 Stroke Master
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Powder Blue said:
Okay...once again I am going to state that most if not all RX1's have this burble even when stock. In my opinion and with some good technical backup to assist my statements, I have found that 100% stock RX1's have this "burble" if you look for it. I will admit that the stock airbox acts like a "muffler" and shrouds the noise but since being made aware of this burble, I can make every single RX1 we have had in the shop do it even on the dyno, but you actually really have to struggle to find it with or without the air filters.
My personal suggestion PB would be to go to the 165 main jets and silver cv slide springs. I have many, many reports back now from lots offolks that ride at high elevation and they tell me that despite the altitude, they find the 165 Main Jets the best performing jets.
I also stated in another post that I beleive that clutching may be the reason that some notice this burble more than others and the fact that you really demanded a lot from your clutching while towing your friend kind of validates my point. When you are raising the RPM towards clutch engagement, the slides are beginning the ascent to open. You really have to think in microseconds here so pay attention... when the clutch engages, and you get into the throttle a bit harder to begin the sled moving, the clutch begins it's upshift, the secondary begins to open and it lugs the engine down in RPM. Microseconds earlier, the slides were happily on their way up when the torque was pulled out of the engine thereby RAISING manifold pressure and dropping in RPM. This makes the slide completely reverse direction and pretty much slam shut, or at least close considerably from where it was headed. This creates a lean condition because you just had all this air gushing in and fuel was beginning to step up as well when the slide closed and closed off the flow of fuel causing a lean spot.
I don't think it is fair to equate the burble with the air kit, but I do understand your desires to want to get rid of it. I think maybe the air kit accentuates a condition that is already there and because the airbox/muffler is gone, it is now more noticeable. Plenty of people have stated that they had this burble in stock condition.
Hope this helps you some!
Freddie
Frostbite
TY 4 Stroke God
Supertuner thanks for the response. I was hoping you'd chime in on this topic.
You state there IS a lean condition as I had observed above. It appears the lean condition manifests itself in the midrange correct? Are not the nozzle size and needle position the predominant tuning vehicles for the midrange? If there is a lean condition in the midrange (and no where else) shouldn't adjusting one of these two items be part of the fix?
My plugs look wonderful when I chop the throttle at WOT but if I do it after a midrange run they displayed a lean condition.
Wouldn't raising my mains to 165 be fixing a problem I do not have?
You state there IS a lean condition as I had observed above. It appears the lean condition manifests itself in the midrange correct? Are not the nozzle size and needle position the predominant tuning vehicles for the midrange? If there is a lean condition in the midrange (and no where else) shouldn't adjusting one of these two items be part of the fix?
My plugs look wonderful when I chop the throttle at WOT but if I do it after a midrange run they displayed a lean condition.
Wouldn't raising my mains to 165 be fixing a problem I do not have?
SUPERTUNER
TY 4 Stroke Master
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Powder Blue said:
Your thinking about using those parts in the carb to tune is sound PB but every jet in the carburetor works ALL the time. One doesn't shut off and another activate. Due to this, you have "fueling overlap" in that the pilot still sprays fuel while the needle jet, needle and main jet are beginning to work harder and harder. The pilot does not shut off at WOT...it merely supplies as much fuel as it could for it's size. The same is true about the main jet.
Think of it this way...if you are using 100% of a 160 main jet but require 102% it will not be able to keep up with the demand. However, using 99% of a 165 main jet will be like the 160 supplying the 102%.
I have convinced a customer to leave his RX1 at my shop to conduct some testing on this for all of you but the weather is not cooperating whatsoever...it was 56 degrees here Christmas eve! Sheesh.
Jingle bells!
Freddie
The sled is obviously too lean at the RPM they burble as more than one person has eliminated it by raising the needle. Others report it diminishes when the sled warms up. I suspect that a better needle taper could be obtained and maybe Freddie might have the resources to test this theory. I have found that needle jets may not be changeable in some of these flat slide carbs but can't say if this applies to the RX1. I think the needle jets are more than adequate as the turbo kits retain the stock ones. I think you should go to 165's and then you may only have to raise the needle one position instead of two. I am willing to bet this will have less of an effect on economy than you think it will.
1xr
Expert
I did have to raise the needle two clips to over come the condition. Fuel economy was'nt much worse than before. maybe about 2 mile less to the gallon.
Frostbite
TY 4 Stroke God
Low flying missle saw right through my argument. Yes, it is all about economy. When I (we) ride out west there is no gas pump to pull up to when you have gone 70 miles. If I can't get 100 miles (125 preferably) I will HAVE to haul gas. I can imagine the howls of laughter from the Naysayers when I pull up on a four stroke hauling gas!
How about the Stanley trip coming up? It's a good 90 miles I'm told from McCall to Stanely if you stay on the trails. I'm thinking this may require extra fuel.
Ok, back to the subject at hand. I have a set of 160, 162.5 and 165 mains already purcahsed and sitting on my bench in teh shop. If I do go to the 165 mains should I leave my needles in the #4 (one click richer than stock) position or go back to #3 (stock).
I would be very tickled to find out (on a dyno) how the needles from a Dynojet kit would work in our beloved RX-1s.
http://dynamic.dynojet.com/cfml/Jetkits/yamahajets.cfm
It COULD contain the answer to questions. Thanks for all the support. PB
How about the Stanley trip coming up? It's a good 90 miles I'm told from McCall to Stanely if you stay on the trails. I'm thinking this may require extra fuel.
Ok, back to the subject at hand. I have a set of 160, 162.5 and 165 mains already purcahsed and sitting on my bench in teh shop. If I do go to the 165 mains should I leave my needles in the #4 (one click richer than stock) position or go back to #3 (stock).
I would be very tickled to find out (on a dyno) how the needles from a Dynojet kit would work in our beloved RX-1s.
http://dynamic.dynojet.com/cfml/Jetkits/yamahajets.cfm
It COULD contain the answer to questions. Thanks for all the support. PB
