99 400 refuses to start

9 replies to this topic
  • gysgtdan

Posted April 01, 2005 - 05:51 PM


So I got back from Iraq and tried to start old faithful and for the first time she refuses to start. I have taken off the carb and cleaned it out throughly with no joy. Replaced the spark plug also still no joy. I got it started once took it for a spin and will not start now. All ideas are welcome.

  • sleeman

Posted April 01, 2005 - 05:54 PM


Is The Air Filter Clean, Is Your Carb Properly Adjusted

  • gysgtdan

Posted April 01, 2005 - 05:58 PM


Cleaned the air filter. Main 178, Pilot #4 pos, fuel screw 2 out. FMF powerbomb and powercore 4 pipe.

  • jrcgaf364

Posted April 28, 2005 - 09:06 PM


got spark...plug gapped.....are u sere you assembled the carb 100 % correct. I usually would try to heat up te plug for a sec that sometimes helps

  • bushy

Posted April 29, 2005 - 02:43 AM


Cleaned the air filter. Main 178, Pilot #4 pos, fuel screw 2 out. FMF powerbomb and powercore 4 pipe.

You mean the needle.
Have you replaced the gas in the tank? Take the carb off again and make sure you can actually see through the pilot and main jet. If you cant then take a small piece of wire and carefully get whatever is clogging it up out of there.

If it ran fine before you put it away then it is a issue of gas gumming up in the jets, do exactly as I told you and make sure to replace the gas! You could also clean the filter to make it a little easier to start. :naughty:

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • gunnydan

Posted April 29, 2005 - 08:43 PM


I now can get the bike started with the choke on and it starts on the fifth kick. Push the choke in and it sputters and dies. I will continue to tinker with the carb. I long for the days when I never had a problem with the beast. And to add insult to injury I now have a nice puddle of coolant on the floor coming from the weep hole on the water pump, time for new seal. A new big blue might be in the future just for reliability reasons. Not giving up on the 400. Thanks Bushy.

  • adrian

Posted April 29, 2005 - 08:59 PM


OLD Gas......

  • Guest_Keenan_*

Posted April 30, 2005 - 08:07 AM


your carburetor jets are probably (most likely) gummed up from the old gas that sat in their for such a long time. your going to need to clean everything out thoroughly.

  • Chris_from_Oz

Posted April 30, 2005 - 09:14 AM


You mentioned you've had your carb' apart. Have you possibly put the slide back in the wrong way? It's real easy to do, and can cause the problems you've described. Worth a look.....

  • gunnydan

Posted April 30, 2005 - 09:16 PM


I took off the carb again and the slide was in the right way. I have already changed the gas. Next step I'm going to replace the diaphragm in the accelerator pump. It turns out I have a #48 in the pilot jet so it should be pretty rich, because the standard is a 45. Blew out all the jets even though they looked clean. Any further suggestions would be appreciated.

Related Content

WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

Need help by Goforaride

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  68 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.