middlman
New member
Has anyone run 147.5 jetting *(mains) on a SXR700 with Bender Tripple Pipes
Bender suggests 150 across the board, but I am dumping raw (unburnt) fuel at WOT.... (also only getting 80 miles on a tank)
Running Clips at 3, 4, 3
I am not too worried since it will be 30 degrees F at riding temp avg but would like to know if anyone has played around with their jetting. It seems Bender runs pretty fat, and I thought I saw some dyno runs with 147.5's in.
I know I need to run and read plugs and temps but just asking from others experiences.
Thanks for any input!!!
Steve Campbell
Bender suggests 150 across the board, but I am dumping raw (unburnt) fuel at WOT.... (also only getting 80 miles on a tank)
Running Clips at 3, 4, 3
I am not too worried since it will be 30 degrees F at riding temp avg but would like to know if anyone has played around with their jetting. It seems Bender runs pretty fat, and I thought I saw some dyno runs with 147.5's in.
I know I need to run and read plugs and temps but just asking from others experiences.
Thanks for any input!!!
Steve Campbell
I'm running 155's with benders and a pretty healthy port job. Doesn't help you answer the question at all, but...
I'd guess you'd be fine with 147's at 30F, but I don't know how that would work at 0ish.
I'd guess you'd be fine with 147's at 30F, but I don't know how that would work at 0ish.
harness racer
New member
150-152-150 mains
3---4----3 clips
p-50's
if your not burning the fuel @ wot there must be something else wrong
vince
3---4----3 clips
p-50's
if your not burning the fuel @ wot there must be something else wrong
vince
middlman
New member
not sure what would be wrong.. could it be too low of octane... I have had to run 91 a lot...?
middlman
New member
can anyone tell me what they are getting for miles on a tank???????
harness racer
New member
185 km/ 115.63 miles
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about 120 trail riding it.
I dont have benders but im running slp pipes with 147.5's across the board, and 9000 rpm, getting around 135 miles to the tank! if your gettin only 80 miles to the tank you have other issues me thinks. probably in your clutching.
harness racer
New member
middlman said:
not a chance , lower the octane the hotter the burn ,
like i said something else is wrong ,
what's the rpm @ wot .
clutching info ? w-s-w , green dot 45 degrees , @ 70 wrap what ?
stator starting to fail ?
want help need info , i have set up a lot of these with benders ,
bufalobob
Member
those pipes have a very distinct sweet spot. first run the carb vent tubes into the air box. 47.5 pilots, all needles on #3 & 150's accross. that will clean it up nicely. @ 30+ degrees 147.5's are safe. my 800 sxr has the same pipes & i run 50 pilots, all needles on #3 & 157.5's accross. btw always run premium fuel.
bob
bob
cheapsx
New member
Just curious, what does running the carb vents into the airbox do?
harness racer
New member
info for yA
When we talk about a balance kit we are referring to an application where the carburetor float bowls are vented into the air box. Each air box is different in terms of size, shape, air entry and number of carburetors it is servicing. One thing is for sure. Each air box has a lot going on that doesn't meet the eye. There is the constant pulsing from one cylinder drawing in air after another. The air volume is tremendous. We have air flow and turbulence not to mention the acoustic resonance. Add all of this together and then try to imagine that each carburetor is seeing the same signal without being equalized. Hard to imagine, isn't it?
Any knowledgeable performance shop or tuner will agree that synchronized carburetors are a must for performance.
Let's take carburetor tuning a step further and talk about various ways that carburetors are vented. Some manufacturers vent their carbs under the hood. This makes the carburetion system vulnerable to under hood pressure. Here is what happens. The faster you go, the more air is forced under your hood. This creates a higher pressure in your float bowl which forces more fuel through your fuel circuit making your engine run richer. In other words, the faster you go, the richer it gets. This robs power from your engine. Let's say you are riding your sled at 50mph into a 25mph headwind. This would raise the under hood pressure equal to riding at 75mph without any headwind. You will be running very rich at only 50mph. The point is that this makes your jetting very inconsistent. When you are dealing with headwinds, tailwinds, or no wind, all of these conditions produce different jetting results.
The next type of carb venting is called atmospheric. The carburetor vent lines are run up the steering post and end up outside of the hood, usually ending up near the handlebar pad. You must make sure not to pinch the vent lines shut when securing them to the steering post or exiting the hood or you will cause fuel starvation and cause engine damage. Other circumstances that could cause jetting variations with this venting method are atmospheric pressure changes, snow or water or air blowing by the end of the vent hoses.
Now let's talk a little about venting carburetors into the air box (Polaris vents their carbs this way). We believe this is the best way due to the overall consistency. This method also circumvents the problems outlined with the other methods, especially the rich condition due to under hood pressure. The negative pressure in the air box reduces fuel delivery in a predictable manner and produces more power.
I can tell you that before you try this make sure you are plenty rich on all circuits , i tried this aswell as a set of pipes on my 600 srx jetted up 5 sizes and it was not enough 2 pistons and a cylinder . by the time my temp gauge
went off it was too late .... no one to blame except myself ...
When we talk about a balance kit we are referring to an application where the carburetor float bowls are vented into the air box. Each air box is different in terms of size, shape, air entry and number of carburetors it is servicing. One thing is for sure. Each air box has a lot going on that doesn't meet the eye. There is the constant pulsing from one cylinder drawing in air after another. The air volume is tremendous. We have air flow and turbulence not to mention the acoustic resonance. Add all of this together and then try to imagine that each carburetor is seeing the same signal without being equalized. Hard to imagine, isn't it?
Any knowledgeable performance shop or tuner will agree that synchronized carburetors are a must for performance.
Let's take carburetor tuning a step further and talk about various ways that carburetors are vented. Some manufacturers vent their carbs under the hood. This makes the carburetion system vulnerable to under hood pressure. Here is what happens. The faster you go, the more air is forced under your hood. This creates a higher pressure in your float bowl which forces more fuel through your fuel circuit making your engine run richer. In other words, the faster you go, the richer it gets. This robs power from your engine. Let's say you are riding your sled at 50mph into a 25mph headwind. This would raise the under hood pressure equal to riding at 75mph without any headwind. You will be running very rich at only 50mph. The point is that this makes your jetting very inconsistent. When you are dealing with headwinds, tailwinds, or no wind, all of these conditions produce different jetting results.
The next type of carb venting is called atmospheric. The carburetor vent lines are run up the steering post and end up outside of the hood, usually ending up near the handlebar pad. You must make sure not to pinch the vent lines shut when securing them to the steering post or exiting the hood or you will cause fuel starvation and cause engine damage. Other circumstances that could cause jetting variations with this venting method are atmospheric pressure changes, snow or water or air blowing by the end of the vent hoses.
Now let's talk a little about venting carburetors into the air box (Polaris vents their carbs this way). We believe this is the best way due to the overall consistency. This method also circumvents the problems outlined with the other methods, especially the rich condition due to under hood pressure. The negative pressure in the air box reduces fuel delivery in a predictable manner and produces more power.
I can tell you that before you try this make sure you are plenty rich on all circuits , i tried this aswell as a set of pipes on my 600 srx jetted up 5 sizes and it was not enough 2 pistons and a cylinder . by the time my temp gauge
went off it was too late .... no one to blame except myself ...
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bufalobob
Member
harness:
very good explanation.
bob
very good explanation.
bob
A couple of bucks
VIP Member
So rejetting is a must when venting into the airbox.
bufalobob
Member
no rejetting is not necessary. the air/fuel ratio is more consistant w/ the vent hoses in the air box. run the jetting i posted earlier. if still burbully @ wot then put in the 147.5's...but i don't think that will be necessary.
bob
bob
nojokef7
New member
I was gonna start a new thread but i guess i'll just jump on this one since its about the same stuff I'm wondering about.
I just put Bender tripple pipes and Bender clutch kit on my SXR 700 with 150 mains across and 52.5 pilots across and clips at 3-4-3
Now when its sits at idle it smoke like crazy and leaves a oily spot on the floor.
So what i'm wondering is should i go down in size on both mains and pilots or just mains or set clips differently or what?? Looking for guys with experience with these pipes...i live in upstate NY so temps are kinda all over but i'd say average is 20-30 degrees if that helps. I also have a set of 3 147.5 mains thinking of trying them maybe.
Any help would be greatly appreciated!!
I just put Bender tripple pipes and Bender clutch kit on my SXR 700 with 150 mains across and 52.5 pilots across and clips at 3-4-3
Now when its sits at idle it smoke like crazy and leaves a oily spot on the floor.
So what i'm wondering is should i go down in size on both mains and pilots or just mains or set clips differently or what?? Looking for guys with experience with these pipes...i live in upstate NY so temps are kinda all over but i'd say average is 20-30 degrees if that helps. I also have a set of 3 147.5 mains thinking of trying them maybe.
Any help would be greatly appreciated!!
JohnnyQuest
Member
Pilot jets control 0-1/4 throttle and also work closely with your fuel screw settings....
Needle settings control 1/4-3/4 throttle
Main jets control 3/4-WFO
gives ya a little insight on what areas you need to focus on while doing your trial and error testing/tuning
Needle settings control 1/4-3/4 throttle
Main jets control 3/4-WFO
gives ya a little insight on what areas you need to focus on while doing your trial and error testing/tuning
bufalobob
Member
nojokef7:
i gave the answer on page 1 of this post?????
bob
i gave the answer on page 1 of this post?????
bob
nojokef7
New member
alright thanks guys that helps me I'm gonna try and get 47.5 pilots after work today and give that a try and keep 150 mains in also put all clips on 3 I hope it works for me. Now is this set up good for like 0-32 degree weather??? Thanks again guys!
nojokef7
New member
Well I ended up with 50 pilots cause my shop didn't have 47.5s so came home and tried them and seems to be a bit better not as smokey as she was before with the 52.5s and idle sounds better. I left the clips at 3-4-3 and 150 mains also fuel screw was at 1 3/4 turns now at 1 1/2 turns. Now i guess i just have to test it.