Parade Lap K5

[Hillclimb#42]

 Hey Guys,
 My K5 always needs a little "parade lap" to warm up and clean out fully. It seems like it cleans out in neutral, but is still loaded up a little at top-end ,in gear,before eventually cleaning out for the rest of the day.
 The problem though, some hillclimbs do not allow pit riding.
1. Does it make any sense that it only cleans out fully, in gear?
2. Can I fix this issue with a float adjustment? or draining gas after a ride?
( Second motor in this bike to have the same trait ) Only happens on first start up of the day...??

[Johnniespeed]

 It was my understanding that this is caused by a cold pipe, and the reversion pulses from the pipe do not work correctly until the pipe is hot.
  I do not claim to fully understand this, but I have watched racers use a "Reddy" heater aimed at thier pipe to preheat the pipe and engine.
 My bike does not seem to "warm up" by just running the engine, I have to ride it for a few minutes to get full power.
  I am sure other people on this site can explain this in a more scientific manner, but for me the "cold pipe theory" is easy to understand.
 John

[Hillclimb#42]

That does seem reasonable. I've seen some guys with their pipes wrapped with insulative tapes to warm them up faster.
  It seems that it can cool off for an hour or more, and will not act the same way it does on first ride of the day. Maybe I'm wrong about that. I thought it may be fuel in the bowl and gas line that may evaporate and leave me with alot of two stroke oil to get burnt out.
  Why doesn't it clean out well in neutral? The pipe will heat up idling.

[tharden]

Mine is the same way.  I can let it idle until warm, but it takes running the bike to clear it out and have power.  I think as you let the engine warm it does not have the proper head temperature to burn the oil in the gas and accumulates in the cylinder and crankcase. Then when you put the engine under the necessary strain it gets to proper head temperature and then clears out the engine.  This is just my thought as the oils in a water cooled engine take a higher head temp to burn compared to a air cooled.   

[KX500freak]

my k5,s are rolling right after starting up ,
then a paradelap :lol:with kindness while opening up throttle bit by bit.
after that its giving you the permission to go full out

[GDubb]

Mine runs good after a short warm-up in neutral without letting it idle much... then I ride it easy until I can tell that the engine is up to temp (first 15 min or so)so I dont cause it to cold-sieze... Otherwise it runs fine fairly cold, I just dont want to damage it.  Also, I ALWAYS drain the bowl after EVERY ride and I always rev it out right before I shut it off with the thought that it will help clean the plug.  I would think that you guys assume that you must ride it in gear to get it to run right when actually you are just causing it to warm up faster because it's under load.  It should warm up fine in neutral... just takes more patience. 


-G

[Hillclimb#42]

Eww, don't know if i like that or not,Gdubb. I used to have a cold-foul issue with my 250. The quick fix was to run it out of gas after riding. ( actual cure was float adjustment)I knew it was out when it started to idle faster. Revving it up while gas is off is forcing a lean, hot condition. That may actually cause wear to rings and cylinder walls.
  It seems that heat alone will not help the performance of the cold natured beast. It acts like once you get to that rpm, it is clean till that point. It will not completely rev until you ride it to that point.
  Is it possible the extra load heats up parts to operating temps that otherwise won't get hot enough unless in gear? I think its a rich condition caused by evaporating fuel, with plenty of extra to be released by the float on every bump, or loading/ unloading. My fuel line is clear and dry at every start-up. Where did the gas go from float bowl and fuel line? Maybe the extra cc's in the k5 makes the condition more noticable than smaller bikes!?

[BDI]

My bike does the same thing, always has. I never gave it much thought Its just what it does. I do know that if you are trying to set the pilot screw on a four stroke the motor has to be warmed up by riding it. If you warm it up by idle alone and set the fuel screw it will be wrong after you go ride it for a couple of miles.this happens no matter how long you let it sit and idle. Perhaps an engines bottom end never truly comes up to operating temp until you put it under load. On a two stroke this may have an impact on the way the motor runs do to the fact that the fuel goes through the bottom first. Maybe the fuel likes to gather and hang out in the cold bottom end of a two stroke and cause a loaded up rich condition. I bet the fuel even helps to keep the bottom end cold until it gets ridden and blown out.

[TheGDog]

Any 2-stroke I've ever ridden never gets warmed-up properly until you go for a short easy-throttled warm-up ride that gets into at least 3rd gear.

And if you try to fight it... try to rush it getting warmed-up any faster... I've always noticed the engine just kinda like refuses to let you wring it out into the high revs until it is ready.  Also, if you try too hard to warm it up you will cause damage.  It's just a question of how much.

[GDubb]

Eww, don't know if i like that or not,Gdubb. I used to have a cold-foul issue with my 250. The quick fix was to run it out of gas after riding. ( actual cure was float adjustment)I knew it was out when it started to idle faster. Revving it up while gas is off is forcing a lean, hot condition. That may actually cause wear to rings and cylinder walls.
 

Not what I meant...  I rev the bike out so it sounds crisp and clear, then as the rpms come down I hit the kill switch. THEN I drain the bowl by turning off the gas and laying the bike over repeatedly until no more fuel comes out of the overflow. I NEVER run the bike out of fuel.


-G

[Hillclimb#42]

Gotcha. GDubb. I've heard of crazier rituals, so i wasn't sure. Not discounting anyone's logic.
  What do you think about your technique? Sounds like you let it warm up plenty either way. My big problem is that some hills don't let you do the warm-up ride and get on the pipe any. They may let you idle around, but not what I know that works. At least I know its a common trait and nothing to start throwing wrenches at.

[Arigato]

Will they allow you to warm it up in gear on a stand?  When we race snowmobiles and there's no room for warm-up runs, we jack up the back end and run the motor full throttle.  Several companies even make the jacks to do it with.  If you had a sturdy enough stand, you could do the same.

[KXcam22]

When I was MX racing you had no choice but to warm the engine up fully while waiting to get on the starting line and then rev the crap out of it while on the line until it reved clean (and then the KX would get the holeshot and leave everyone in the dust). Cam.

[GDubb]

  What do you think about your technique? Sounds like you let it warm up plenty either way.

My warm up works great for my situation. I dont race, and my main concern is making sure my motor lasts as long as possible.  With racing I'm sure the main concern is winning, and the wear and tear and maintenance and the costs of such go way up.  I dont see why they wouldnt allow adequate warm ups at races or hillclimbs.  In the spirit of competition it seems they would want you running a machine at the peak of its capabilities, not cold and sputtering.

[kaw rider]

needle valve gets whore out boucing on trailer. do you shut pitcock off when not in use. have you pressue checked your needle & seat.