messed problem ?!?

[synergycycle]

so I took my 2007 ktm sxf 250 to bruderhiem on sunday. It ran good, when I kill it with the kill switch it starts back up first kick but when im riding it hard and stall it I cant start it by kicking it. I have to bump start it wich sucks!!! what do you think is wrong?

 

[-LadyDirt-]

lol i was having the same problem on Sunday too, i was riding in Redwater and ya same thing, it wasn't starting after I stalled, which happened lots because the sand was just too gnarly and I laid her down a couple times coming too fast around corners, etc and losing control when the front end just got too wobbly..if I killed it though, it started no problem. I'm not sure what the case was, but hasn't happened to me yet. I barely bagged the thing though..I didn't get out of 2nd gear, and it was a pretty warm day and the bike was working extra hard to get through that sand...

 

[willjeffwilljeff]

check the valves

 

[Modman]

sounds like when you stall it under load that its possibly getting too much fuel? Once the ignition shuts off, there might be some residual fuel in the carb throat that's getting pulled into the motor. next time it does it, before you try and kick start it, pull the plug and have a look, if its wet, that's possibly what's happening. Either that or it might be a vacuum issue when stalling it under load, not enough vacuum at the fuel pump? I'm assuming its a mechanical pump, not an electric.

Without being there to see how it runs, its really hard to say. Hard starting when hot can be a number of things.

 

[john s]

You could look into getting a hot start kit like the wr250/450's have maybe it might be running abit rich.

 

[willjeffwilljeff]

are you giving it any gas before you kick it?

 

[-LadyDirt-]

I don't think i was having as much of an issue as Andre, mine would eventually start it just took like 5 good thrusty kicks in a row every now and then, after I stalled it..and yeah this is after i laid it down, and I was tired as hell i definitley wasn't too stealthy at picking it up again so it could have just been a bit flooded lol.

 

[ktm 13-44]

maybe your bike knows that deep down you really secretly wish it was a 2-stroke and not 4. That would explain your bikes hesitation to cooperate....

There is one sure-fire way of finding a fix for your 4-stroke however...

1. Remove your wallet from your back pocket
2. open your wallet
3. remove all your credit cards. Put said credit cards into a blender. you will need to feed these to your 4-stroke, so make sure you get them ground up as fine as possible. 4-strokes dont like to chew.
4. Remove as many large bills as you can find in your wallet. 4-strokes LOVE having large bills used as muffler packing.

 

[synergycycle]

sounds like when you stall it under load that its possibly getting too much fuel? Once the ignition shuts off, there might be some residual fuel in the carb throat that's getting pulled into the motor. next time it does it, before you try and kick start it, pull the plug and have a look, if its wet, that's possibly what's happening. Either that or it might be a vacuum issue when stalling it under load, not enough vacuum at the fuel pump? I'm assuming its a mechanical pump, not an electric.

Without being there to see how it runs, its really hard to say. Hard starting when hot can be a number of things.

it was running good, I wasnt giving it gas when I kicked it. I was running a 170 main and a 42 piolt. I tried a 45 piolt and a 175 main yesterday and it was backfireing a bit. maybey it was a cloged air filter, it was SUPER dry, and all the other non ktm homo's were roosting me. I took off my carb yesterday and cleaned the hole thing out. the only dirty thing was there was some grit in the manual fuel pump. I checked my valves and they were a bit to tight. that also could be a problem. the bike has been race ported by bondi engines. what should I be doing differnt? cpould it be the float level?

 

[clint/KTM/16]

easy fix... don't stall it. LOL jk:d

 

[teeroy]

it's the nature of the beast. just watch any moto-x race when them fellas stall their 4 stroke race bikes after a crash.....sometimes they just give up trying to start them.

 

[Modman]

the bike has been race ported by bondi engines.....

OK, now you tell us........ported motor totally different than stocker.

Its obviously a problem with it stalling under load because it does not do it when you idle it down and shut it off with the kill switch. This leads me to believe that because you typically do not shut a bike off with the throttle in the wide open position (usually the throttle is pretty well all the way "off") so killing it with the throttle "off" means that it has had a chance to burn residual fuel from the carb throat before you kill it. To me then - there is the possibility when the throttle is "on" and you stall it under load, it does not have the chance to burn up the excess fuel in the carb throat, and it pulls it into the motor and floods it slightly.

Doubtful it would be the valves for the simple fact that it should be hard to start all the time if your valves were too tight and affecting it, regardless of whether you used the kill switch or stalled it. It has something to do with whatever changes when you stall it under load vs not under load. Valved dynamics do not change from load to no load.

That's my theoretical "engine" explanation without seeing and riding the bike myself. Like teeroy says, could be a tempermental SOB too, especially since its ported.

Only real way to check this is to pull the plug the next time you stall it under load and see what it looks like. If its not that, then move on to next possibility.

 

[synergycycle]

OK, now you tell us........ported motor totally different than stocker.

Its obviously a problem with it stalling under load because it does not do it when you idle it down and shut it off with the kill switch. This leads me to believe that because you typically do not shut a bike off with the throttle in the wide open position (usually the throttle is pretty well all the way "off") so killing it with the throttle "off" means that it has had a chance to burn residual fuel from the carb throat before you kill it. To me then - there is the possibility when the throttle is "on" and you stall it under load, it does not have the chance to burn up the excess fuel in the carb throat, and it pulls it into the motor and floods it slightly.

Doubtful it would be the valves for the simple fact that it should be hard to start all the time if your valves were too tight and affecting it, regardless of whether you used the kill switch or stalled it. It has something to do with whatever changes when you stall it under load vs not under load. Valved dynamics do not change from load to no load.

That's my theoretical "engine" explanation without seeing and riding the bike myself. Like teeroy says, could be a tempermental SOB too, especially since its ported.

Only real way to check this is to pull the plug the next time you stall it under load and see what it looks like. If its not that, then move on to next possibility.

I took out the plug yesterday and the gap was a bit to small. Im going to re-jet the carb and see if it helps. I put it richer becuase I thought it was lean, im going to put it back ti a 168 main with a 40 or 38 piolt.

 

[-LadyDirt-]

maybe your bike knows that deep down you really secretly wish it was a 2-stroke and not 4. That would explain your bikes hesitation to cooperate....

There is one sure-fire way of finding a fix for your 4-stroke however...

1. Remove your wallet from your back pocket
2. open your wallet
3. remove all your credit cards. Put said credit cards into a blender. you will need to feed these to your 4-stroke, so make sure you get them ground up as fine as possible. 4-strokes dont like to chew.
4. Remove as many large bills as you can find in your wallet. 4-strokes LOVE having large bills used as muffler packing.

Hahaha...

 

[dooryder]

I took out the plug yesterday and the gap was a bit to small. Im going to re-jet the carb and see if it helps. I put it richer becuase I thought it was lean, im going to put it back ti a 168 main with a 40 or 38 piolt.

he means check the plug if its wet after it stalls under load leaving unburnt fuel

 

[synergycycle]

he means check the plug if its wet after it stalls under load leaving unburnt fuel

I know

 

[willjeffwilljeff]

Go to KTMTalk and read about jetting for your bike.

 

[synergycycle]

it was running good when it was running.....

[YOUTUBE]http://www.youtube.com/watch?v=fKGqmOLo7gU[/YOUTUBE]

 

[GasCan]

Where was that ride at?

 

[synergycycle]

Where was that ride at?

bruderhiem AB