KX Riders

Maintenance & Technical => KX500 Original => Topic started by: Ramski on April 18, 2005, 02:38:50 PM

Title: Motor bogs at high speed
Post by: Ramski on April 18, 2005, 02:38:50 PM

Never had this problem yet.  I did a desert race this last weekend and noticed in a fast section wide open my bike started to bog like it was out of gas.  I came off the throtle and it went away.  Few minutes later on another high speed wash and this time the bike died.  Waited a few minutes and bike fired right up and I never had the problem again but it did sound like it wasn't running the same as always.

Jetting?  Dirt in the carb?  My muscles and bones still ache from the race so I havn't got around to really looking at it all yet.  Any ideas?  Thanks.

Title: Motor bogs at high speed
Post by: Arigato on April 18, 2005, 03:00:27 PM

It may have partially siezed.  What does the plug look like?  
or
I had a CR500 that did that due to blow-by when the piston and rings were past their service life.

Title: Motor bogs at high speed
Post by: hoopty on April 18, 2005, 04:05:32 PM

I had one do that with the stock fuel line on it, I put a piece of gates 3/8 fuel line on there and never had that "running out of fuel" feeling again ;)

Title: Motor bogs at high speed
Post by: KXcam22 on April 18, 2005, 04:59:19 PM

Dan,
  Good suggestions.  The mild seizure thing is very likely.  Also check your tank vent to see if it is partially plugged.  This is rare but I have had it happen.  If no (or not enough) air can get into the tank it can vacuum lock at high speed and starve the carb.  If you pull the cap off right away after it dies there will be a hiss and you can easily tell if this might be the prob.  Hope this helps. Cam.

Title: Motor bogs at high speed
Post by: reknelb on April 19, 2005, 12:22:03 AM

This used to be a common problem on some of the old road race bikes I had. I used to always go with a high flow fuel petcock (pingel, etc.), or gut out the stocker and drill it out so it had a bigger diameter. Check the float level too, if its too high, you wont have as much fuel in the bowl.

Title: Motor bogs at high speed
Post by: Ramski on April 20, 2005, 06:28:06 PM

The vent hose might be it.  It was my first ride out with new tank and I added a new vent hose that has the swivel thingy to prevent kinks.  Might be the prob.  Thanks everyone.

Title: Motor bogs at high speed
Post by: Mhardee on April 22, 2005, 01:56:45 AM

I went through this a few months ago and what I found was embarrassing... the float level was way off! Fixed it and it runs like a scalded ape..