Hardcore Sledder banner
1 - 16 of 16 Posts

·
Registered
Joined
·
54 Posts
Discussion Starter · #1 ·
hi i have an iqr 440 2007 the carbs we all just redone from top to bottom. we still cannot figure out why this bogg is occurring it boggs off the line then pulls good at half throttle and then it bogg over half when u put it to the bar. the clutching is stock, the reeds are brand new mint condition, power valves r clean i cannot figure this problem out for the life of me please help me!!!!
 

·
Registered
Joined
·
4,541 Posts
Look closely at you choke cable from under the console ( between console and airbox). Sometimes when putting in the AirBox you can kink the square plastic box where the choke cables come together. One of the little clips on the cable box pops out and it applies the choke to one or more cylinders.

Look closely at your choke lever on the console. There should be plenty of gap between the lever and the choke housing when the choke is not turned on. If the lever is not loose and is tight against the housing your cable box is kinked like mentioned above or your chokes are not adjusted properly.

You can also grab the choke cables where they attach to the plunger at the carb body. there should be some play in the cable down at the carbs. If one or both of your cables are tight with no free play you could be holding up one or both plungers.

Your symptoms do not sound exactly like this problem. Usually when you partially apply the choke the sled will idle poorly but bog terribly off the line and any time the sled is run except WOT. At WOT the sled will clear up and pull hard after about a 1-2 second bog. Yours sounds a little different but it's worth a look.
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #3 ·
Look closely at you choke cable from under the console ( between console and airbox). Sometimes when putting in the AirBox you can kink the square plastic box where the choke cables come together. One of the little clips on the cable box pops out and it applies the choke to one or more cylinders.

Look closely at your choke lever on the console. There should be plenty of gap between the lever and the choke housing when the choke is not turned on. If the lever is not loose and is tight against the housing your cable box is kinked like mentioned above or your chokes are not adjusted properly.

You can also grab the choke cables where they attach to the plunger at the carb body. there should be some play in the cable down at the carbs. If one or both of your cables are tight with no free play you could be holding up one or both plungers.

Your symptoms do not sound exactly like this problem. Usually when you partially apply the choke the sled will idle poorly but bog terribly off the line and any time the sled is run except WOT. At WOT the sled will clear up and pull hard after about a 1-2 second bog. Yours sounds a little different but it's worth a look.[/b]
thanks alot if you have any more info i would greatly appreciate it
 

·
Registered
Joined
·
4,541 Posts
thanks alot if you have any more info i would greatly appreciate it[/b]
So appearently the choke isn't the problem and you need more help figuring out the bog???

I'm guessing you checked it or already knew the choke isn't the problem???

I'll keep thinking. In the mean time could you give us a little more info about your motor, like:

Compression
Jetting
Fuel you are using
How new is the primary spring
Mixture screw setting on carbs
Pump or Race fuel head
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #5 ·
So appearently the choke isn't the problem and you need more help figuring out the bog???

I'm guessing you checked it or already knew the choke isn't the problem???

I'll keep thinking. In the mean time could you give us a little more info about your motor, like:

Compression
Jetting
Fuel you are using
How new is the primary spring
Mixture screw setting on carbs
Pump or Race fuel head[/b]
the high comp domes are on it and it has 175 psi of compression, the jest the piolot is a 40 and the mains are 270's and the needle is on the third clip. we are 645 ft above sea level and the temp when i last ran it was around - 10. the primary spring only has maybe 100 miles on it, the air screw on the carb is .75 ( three quarter turn out) and im running sunoco blue 110 octane with amsoil dominator, help me please haha i have tried almost everything muchly appreciated
 

·
Registered
Joined
·
4,541 Posts
Are we talking -10C or -10F???

If you are talking about -10C then 270 is a little big on the MJ.

At -10F your 270 should be close enough to run.

-10C = +14F. For racing @ 650' I would be running a 240MJ maybe even 230 for shorter tracks. I would also open your air screw to 1 turn or maybe even try 1.25. I know .75 turns is stock but you may have a rich bog off the bottom and need a tad more air.

You are calling yours a Bog at Wide Open Throttle. Is it a bog or does the motor just quit pulling about 7000 to 7500RPM or less???

Is this sled new to you??

Did it always run like this??

Have you had the recoil off to adjust the stator??

Are the EV solenoids plugged in??

Consider temporarily disconnecting the EV Solenoids at the housing nipples (rubber hoses coming off the EV housings) and using one of the pieces of tubing and connecting the two nipples together. this will bypass the solenoids and tell you if they are the possible cause of your trouble.

Also Try running the motor up on the track stand. Does the secondary open slowly and close quickly?? Could the secondary be opening too soon, allowing the primary to shift out too soon?? If the secondary is shifting to quickly the primary will load the motor to quickly and make it Bog Down like you are explaining. May need a new secondary spring.
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #7 ·
Are we talking -10C or -10F???

If you are talking about -10C then 270 is a little big on the MJ.

At -10F your 270 should be close enough to run.

-10C = +14F. For racing @ 650' I would be running a 240MJ maybe even 230 for shorter tracks. I would also open your air screw to 1 turn or maybe even try 1.25. I know .75 turns is stock but you may have a rich bog off the bottom and need a tad more air.

You are calling yours a Bog at Wide Open Throttle. Is it a bog or does the motor just quit pulling about 7000 to 7500RPM or less???

Is this sled new to you??

Did it always run like this??

Have you had the recoil off to adjust the stator??

Are the EV solenoids plugged in??

Consider temporarily disconnecting the EV Solenoids at the housing nipples (rubber hoses coming off the EV housings) and using one of the pieces of tubing and connecting the two nipples together. this will bypass the solenoids and tell you if they are the possible cause of your trouble.

Also Try running the motor up on the track stand. Does the secondary open slowly and close quickly?? Could the secondary be opening too soon, allowing the primary to shift out too soon?? If the secondary is shifting to quickly the primary will load the motor to quickly and make it Bog Down like you are explaining. May need a new secondary spring.[/b]
im talking -10 i tested it out tonite and it was around -1 or -2 and it was better after i had changed the gas cap because it was plugged. there is still a little hesitation off of the line but it is way better top end wht do you think would be causing that bogg with the 270 mj's in it it had almost a perfect burn what do u think could still be wrong?
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #8 ·
Are we talking -10C or -10F???

If you are talking about -10C then 270 is a little big on the MJ.

At -10F your 270 should be close enough to run.

-10C = +14F. For racing @ 650' I would be running a 240MJ maybe even 230 for shorter tracks. I would also open your air screw to 1 turn or maybe even try 1.25. I know .75 turns is stock but you may have a rich bog off the bottom and need a tad more air.

You are calling yours a Bog at Wide Open Throttle. Is it a bog or does the motor just quit pulling about 7000 to 7500RPM or less???

Is this sled new to you??

Did it always run like this??

Have you had the recoil off to adjust the stator??

Are the EV solenoids plugged in??

Consider temporarily disconnecting the EV Solenoids at the housing nipples (rubber hoses coming off the EV housings) and using one of the pieces of tubing and connecting the two nipples together. this will bypass the solenoids and tell you if they are the possible cause of your trouble.

Also Try running the motor up on the track stand. Does the secondary open slowly and close quickly?? Could the secondary be opening too soon, allowing the primary to shift out too soon?? If the secondary is shifting to quickly the primary will load the motor to quickly and make it Bog Down like you are explaining. May need a new secondary spring.[/b]
i was talking in degrees celcius sorry
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #9 ·
Are we talking -10C or -10F???

If you are talking about -10C then 270 is a little big on the MJ.

At -10F your 270 should be close enough to run.

-10C = +14F. For racing @ 650' I would be running a 240MJ maybe even 230 for shorter tracks. I would also open your air screw to 1 turn or maybe even try 1.25. I know .75 turns is stock but you may have a rich bog off the bottom and need a tad more air.

You are calling yours a Bog at Wide Open Throttle. Is it a bog or does the motor just quit pulling about 7000 to 7500RPM or less???

Is this sled new to you??

Did it always run like this??

Have you had the recoil off to adjust the stator??

Are the EV solenoids plugged in??

Consider temporarily disconnecting the EV Solenoids at the housing nipples (rubber hoses coming off the EV housings) and using one of the pieces of tubing and connecting the two nipples together. this will bypass the solenoids and tell you if they are the possible cause of your trouble.

Also Try running the motor up on the track stand. Does the secondary open slowly and close quickly?? Could the secondary be opening too soon, allowing the primary to shift out too soon?? If the secondary is shifting to quickly the primary will load the motor to quickly and make it Bog Down like you are explaining. May need a new secondary spring.[/b]
i had it out tonite and it was around -1 , -2 degrees celcius and it pulled great top end with the 270mj's in it and it did that because we fixed the vent on the gas cap because it was clogged. but there is still a little bogg or hesitation off of the line do u kno what this could be?
 

·
Registered
Joined
·
4,541 Posts
So at -10C you should consider a 240MJ if you are SnoX racing the sled. I know it sounds lean but I run mine with a 230 at sealevel at that temp. SnoX only.

If you are afraid of the 240 at least drop down to a 250MJ. Run it a little and see if the upper RPM bog goes away or gets better or worse. Then we can fix your off idle bog.
 

·
Registered
Joined
·
4,541 Posts
A momentary bog off idle or anywhere under about 4000RPM is ususlly a Lean Bog. You need to raise the needle (lower the clip) to clear up a lean bog. A bog that has the motor running crappy for a while till it gets going and finally clears up and comes to life is usually a rich bog and can be cleaned up by lowering the needle (raise the clip).

Leave your Air Mixture screw at .75 turns out. This is the recommended starting point.

Try a needle clip position change and see if your bog goes away.

270 is still to big for SnoX at those kinds of temps.

You never said if you are Racing this sled or trail riding it on Race Fuel???
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #12 ·
A momentary bog off idle or anywhere under about 4000RPM is ususlly a Lean Bog. You need to raise the needle (lower the clip) to clear up a lean bog. A bog that has the motor running crappy for a while till it gets going and finally clears up and comes to life is usually a rich bog and can be cleaned up by lowering the needle (raise the clip).

Leave your Air Mixture screw at .75 turns out. This is the recommended starting point.

Try a needle clip position change and see if your bog goes away.

270 is still to big for SnoX at those kinds of temps.

You never said if you are Racing this sled or trail riding it on Race Fuel???[/b]
i will be doing both with it and moer for racing tho, i have the rpm's at 5300 then hammer on it and it boggs then takes off, and you still think i should go down in jets? im running 270's and they have a good burn on them no white
 

·
Registered
Joined
·
4,541 Posts
If you are going to trail ride the sled then 270's will be OK. If you are going to race the sled then 270's are leaving some HP and acceleration on the table. Your Dragon Button will never work properly with that MJ at the Temps we were discussing yesterday.

The bog you still have can be cleared up by raising the needle 1 position.

You can jet the sled how you want to and only lean it down as much as you feel safe. I have hundreds of hours tuning these 440 for SnoX racing and have never run a MJ bigger than 250 and that was for -15C. Most of the time I am jetting with a MJ in the 220-240 range, sometimes even going down to 210 in the Spring time when it's approaching +5C. This is for SnoX racing and not anything else. And down much further than that while riding in the mountains.

Most SnoX races are won or lost on the starting line. If you don't get the motor up to operating temp and the Pipe Hot you will loose lots of acceleration right when the Green flag drops. The pipe doesn't get hot if you are jetted to fat on the MJ.

Raise the needle one position and your 5000RPM bog will likely go away.
 

·
Registered
Joined
·
6,556 Posts
On straight race fuel the plugs should be almost white. If not, you are too rich. When too lean, the porcelin on the plug will start to color the same as the fuel color, from the dye.
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #15 ·
On straight race fuel the plugs should be almost white. If not, you are too rich. When too lean, the porcelin on the plug will start to color the same as the fuel color, from the dye.[/b]

the plugs are a brown plug and i didnt know with the fuel they should be white thank you for all your help and im going to drop the jets down to the 260's just to see the colour of the plugs and it might take away the problem and if not i will do the needle thanks ... and just wondering wht jets should i be ruunning around -5 to -10 degress celcius?
 

·
Registered
Joined
·
3 Posts
Check your Exhaust valve selenoid, disassemble them (unscrew the round part with wire from the base) clean the spring, piston and all hose, with time oil and moisture turn into grease that retard the openning/closing of the selenoid that result in a bad bog off the line and each time your RPM drop below 7100 RPM and you reaply throttle.
 
1 - 16 of 16 Posts
Top