Newbie hear major problems??

2fastrc · 09-30-2009, 9:34 PM

Kick butt site guys...Hey i have a question or concern. I just picked up a 01 rc51 with 3,500 miles on it. In the last month i have put on 1300 miles. GREAT> heres my prob..i have the yoshi stainless system on it and i noticed that the rear cylinder pipe is turning RED/ORANGE hot just at idle
[cant tell while im driving}. there is no power commander on the bike yet, it looks as if there may have been one mounted to the pcm at one time {there is velcro stuck on it} like i said i just noticed it so not really sure how long this has been going on any help would be greatly apprciated thanks a lot guys!! or should i be looking elsewhere for the prob...

SubSailor · 09-30-2009, 11:41 PM

Red hot at idle? For real?
What does your spark plug look like?
If the porcelain is light gray or white, or is it tan?
If it's white or has speckles, then the bike is running way lean. If it's tan, then it's at least running at or close to normal.
The previous owner probably pulled the power commander to re-sell.
However it would have to be running super lean to cause the pipe to glow at idle. Under power I can understand.

2fastrc · 09-30-2009, 11:58 PM

ok..If i start it up its fine till the temp gets up to 175-180 then the rear starts glowing orange. So i took it for a ride around the block and back in the garage so i could see if was still glowing and it was not.. but then i let it idle again and sure enough it started glowing again! I guess ill pull my plug tomrrow and see what it looks like.. just think i wouldve noticed the glowing before,,,,that is if it is the lack of the power commander

Bigtoe · 10-01-2009, 12:49 PM

Pull the plugs like SubSailor said first. Then report what condition they're in.

2fastrc · 10-01-2009, 1:32 PM

k..i pulled the rear plug and it is more white than any other color {little bit of hint of tan} the plug was very lose!! i put my socket and extension in and put the ratchet on there was no pry or grunt. i would say that it was not even finger tight?

SubSailor · 10-01-2009, 3:11 PM

Well finger tight is certainly not good!!
I had a spark plug get spit out the head from a mechanic not doing his job right. Quite a nice loud noise it made.

If your plug is mostly white, then either the engine is running way lean or the plug heat range is incorrect. I'd check the plug first to ensure it's the correct type.

Here's a plug from my bike after the last service.
This illustrates the typical color a plug tip shows with good fuel ratio.
The color can be a little darker, but not way dark or way light.
White is not good, and dark speckles with white indicates possible aluminum coming off the piston or overheated porcelain. Also not good.

http://i407.photobucket.com/albums/p.../sparkplug.jpg

2fastrc · 10-02-2009, 9:07 PM

K yeah there were no speckles or anything, was just a little whiter than yours. I did notice that when it is at idle and it starts getting orange? if i rev it up some the exhaust will actually cool down.

zerogara · 10-03-2009, 5:46 PM

These engines don't like idling that much, neither do MX 450-530s, the only way to leave the low end and go to the mid range where the engine just begins to function as it was designed is to start off lean and richen up to normal. Most maps will really make them richer on the bottom but then you'll have to watch for fouling plugs and how jumpy the bike gets and how abruptly it wants to rev down.
I warm up the engine and as soon as I get a reading I start rolling mildly. Just don;t race it cold but once a reading of temp. registers start rollling.
The pipe getting hot is not that bad, there have been cracked headers reports, but your main concern is all that heat getting to the shock.

2fastrc · 10-03-2009, 11:44 PM

WOW.. sounds like you guys know your stuff.. what to you think about me getting a PCII commander over the PCIII i can get the II for 130 or i can get the III for 270