HELP! 2003 wr450 supermoto hiccups NOT TPS

[sweendogie]

my bike is a street legal supermoto it has a 478 big bore kit stock compression, web cams, and a vortex ignition and rode fine yesterday, today i went to the gas station and filled it up and now it seems to hiccup while holding a steady throttle...

any suggestions? bad gas maybe? bad petcock? do i need to run high octane with the webcams or will premium pump gas be fine? i just bought the bike yesterday it has been mechanic owned for its entire life and is very close to pristine condition

[William1]

You just bought the bike and it has a issue? Contact the seller.

[sweendogie]

You just bought the bike and it has a issue? Contact the seller.

thanks for the help william

it was like that when i bought it i've already talked to him, ive done hours of searching but cant find anything other than a possible jetting problem... it didnt bother the previous owner but i want to fix it, seems to be different when i switch maps on the vortex ignition, TPS is in spec and unplugging it doesnt do anything at all, either does changing the needle position. it currently has a 178 main and a 50 pilot, if anyone has any input that can point me in the right direction it would be appreciated thanks

[FORMA MOTO]

If you could be more specific, we can be more helpful:

Define specifically when the odd running happens and what is sounds and feels like.

RPM

Throttle position

Accelerating

Decelerating

Does turn the fuel screw far out or far in (once the bike is running) make any differences?

[sweendogie]

If you could be more specific, we can be more helpful:

Define specifically when the odd running happens and what is sounds and feels like.

RPM

Throttle position

Accelerating

Decelerating

Does turn the fuel screw far out or far in (once the bike is running) make any differences?

throughout the middle rpms, constant throttle at about a 1/8th-3/4 turn, doesnt do it in 5th gear at low rpms very bad, very light acceleration it does it a little bit but mostly at a steady cruising throttle, it bugs me everything points to the ignition and TPS mapping but from what i've read the vortex ignition should pretty much clear it up... and if that doesnt clear it up unplugging the TPS should but it doesnt... i have tried maps 2, 7, 9 and 10 (the default traction map) and the only one that isnt horrible is #10 but its still there it doesnt bother me when im driving straight but while turning it can be pretty sketchy

[FORMA MOTO]

throughout the middle rpms, constant throttle at about a 1/8th-3/4 turn, doesnt do it in 5th gear at low rpms very bad, very light acceleration it does it a little bit but mostly at a steady cruising throttle, it bugs me everything points to the ignition and TPS mapping but from what i've read the vortex ignition should pretty much clear it up... and if that doesnt clear it up unplugging the TPS should but it doesnt... i have tried maps 2, 7, 9 and 10 (the default traction map) and the only one that isnt horrible is #10 but its still there it doesnt bother me when im driving straight but while turning it can be pretty sketchy

Hmmmm.............sure sounds like ignition to me.

But not likely with the Vortex on there......

I would look at these:

- worn needle jet (ovalized)

- leaky hot start plunger

- worn throttle body (evidenced by excessive wear from the slide wheels)

- leaking exhaust valve

- dying stator ( would get worse as it gets hotter)

- air jet too lean

[William1]

thanks for the help william

it was like that when i bought it i've already talked to him, ive done hours of searching but cant find anything other than a possible jetting problem... it didnt bother the previous owner but i want to fix it, seems to be different when i switch maps on the vortex ignition, TPS is in spec and unplugging it doesnt do anything at all, either does changing the needle position. it currently has a 178 main and a 50 pilot, if anyone has any input that can point me in the right direction it would be appreciated thanks

That bit of information is helpful. Why do people always leave out details like this? Your first post inferred the bike was fine until you put fuel in it.

Pilot jet and main jet are both abnormally large. Sounds to me like it was arbitraially jetted. what size slow air jet and main air jet is in it? I am suprprised if it were mechanic owned, he did not bother to properly jet the bike.

First get the pilot circuit right:

Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.

Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.

*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***

Turn the screw in until the idle becomes rough or the bike stalls.

if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.

If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.

Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.

If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.

If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.

If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.

Then the main:

Starting with the recommended main, remove the airbox door and go for a ride (bike fully warmed up, 3rd or fourth gear, up a slight hill). Is it better or worse?

If it is better, you need a smaller main.

Go down one size, replace the airbox door, ride. Remove the airbox door and test again. Better or worse? If better, go down a size again. Keep repeating this till the test with the airbox door is worse.

If it was worse with the airbox door removed, tape over 1/3 of your airbox opening, test (airbox door on, of course).

If it is worse now with the tape and was worse with the airbox door off, your main is just right. You are done!

If it seems better, you need to go up a size in main jet. Then test it again (remove the tape). Replace the tape, test again. If with the tape on it is better, go up another size in main. Keep repeating this till having the tape on is worse than with it off.

To finish up and ensure you are set accurately, retest the bike with the tape off (airbox door on), ride it, then remove the airbox door (tape off, of course). Best performance should be with the airbox untapped, airbox door on.

Remember, the main only operates at WOT. Ideally, you want to be in 3rd or 4th gear doing the tests, hitting max revs (just shy of the limiter) for at least 10 seconds to get an accurate representation of the jet status.

You'll need to follow a similar procedure and test the throttle in 1/8th steps to find if the needle is correct.

The WR does have an inherrent stutter due to the CDI. The Virtext has it too aina few of its maps but there a couple that do not have the stutter.

[sweendogie]

That bit of information is helpful. Why do people always leave out details like this? Your first post inferred the bike was fine until you put fuel in it.

Pilot jet and main jet are both abnormally large. Sounds to me like it was arbitraially jetted. what size slow air jet and main air jet is in it? I am suprprised if it were mechanic owned, he did not bother to properly jet the bike.

First get the pilot circuit right:

Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.

Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.

*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***

Turn the screw in until the idle becomes rough or the bike stalls.

if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.

If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.

Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.

If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.

If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.

If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.

Then the main:

Starting with the recommended main, remove the airbox door and go for a ride (bike fully warmed up, 3rd or fourth gear, up a slight hill). Is it better or worse?

If it is better, you need a smaller main.

Go down one size, replace the airbox door, ride. Remove the airbox door and test again. Better or worse? If better, go down a size again. Keep repeating this till the test with the airbox door is worse.

If it was worse with the airbox door removed, tape over 1/3 of your airbox opening, test (airbox door on, of course).

If it is worse now with the tape and was worse with the airbox door off, your main is just right. You are done!

If it seems better, you need to go up a size in main jet. Then test it again (remove the tape). Replace the tape, test again. If with the tape on it is better, go up another size in main. Keep repeating this till having the tape on is worse than with it off.

To finish up and ensure you are set accurately, retest the bike with the tape off (airbox door on), ride it, then remove the airbox door (tape off, of course). Best performance should be with the airbox untapped, airbox door on.

Remember, the main only operates at WOT. Ideally, you want to be in 3rd or 4th gear doing the tests, hitting max revs (just shy of the limiter) for at least 10 seconds to get an accurate representation of the jet status.

You'll need to follow a similar procedure and test the throttle in 1/8th steps to find if the needle is correct.

The WR does have an inherrent stutter due to the CDI. The Virtext has it too aina few of its maps but there a couple that do not have the stutter.

thank you! theres a handlebar switch for the vortex ignition, if i go to one of the power settings on the vortex ignition it makes the hiccup worse even when i go back to the x10 traction setting and doesnt clear up unless i mess with it for awhile, i did this while at the gas station (which was my first ride on the bike after bringing it home) that is why i thought it was possibly the gas

also i completely forgot to add that it has a custom airbox/pod filter... the airbox was gutted and there is no front to the box and there is a screen cut out for the side quick release door

[William1]

'Pod' filters are notorious and have a rep for 'slowed down for racing'. They promote poor air flow at the carb bell being disruptive to the signal provided to the slow and main air jets. Source a replacement airbox and carb boot. Airbox needs no more than about a 16 square inch opening max. Any more is pointless. WR airboxes have scribe marks from the factory for the ideal opening size and location.

Tests have been done on the 'WR hiccup'. The vortex has at least one map (possibly more, memory fails me) that allows the bike to run steady throttle with no misfires. Other maps and the stock CDI has the stutter.

[sweendogie]

'Pod' filters are notorious and have a rep for 'slowed down for racing'. They promote poor air flow at the carb bell being disruptive to the signal provided to the slow and main air jets. Source a replacement airbox and carb boot. Airbox needs no more than about a 16 square inch opening max. Any more is pointless. WR airboxes have scribe marks from the factory for the ideal opening size and location.

Tests have been done on the 'WR hiccup'. The vortex has at least one map (possibly more, memory fails me) that allows the bike to run steady throttle with no misfires. Other maps and the stock CDI has the stutter.

7 is suppose to be the map with no hiccup, however on my bike it does hiccup thats why im wondering if possibly my TPS or my ignition is bad... i did check the TPS though and its in spec at .73dcv... the bike has good power it revs very well it doesnt seem like its the jetting but im not an expert when it comes to jetting a carb, i found a stock airbox/boot with a small hole cut in the side for $20 so i might try that

[William1]

I know they are 100% programmable and there is no guarantee a used one is still containing the stock Vortex programs. So map 7 may or may not be a OEM Vortex map 7. Only a Vortex dealer can tell.

Earlier in the thread, you said you found setting(s) that the bike ran fine on. Why not use that?