yzf450 2006 few issues

[_JoNeS_]

Just bought a used 2006 yzf450 from a local shop, it had been sat for a while in there but still started, on the night I picked it up the shop guy had put a few plug in it for me and air filter, and it started fine. Now when I come to start it it seems to take a while to start up, when it does fire up the header pipe seems to glow after about 20 seconds of idling, not sure if this is normal or not, I also noticed after trying to kick it up for a while a small amount of what looked like coolant on the floor (green/ blue colour), it also seems to be back firing and popping (flames) quite a bit, is this all normal ? do you suggest I drain the tank and carb and put fresh fuel in her see if it makes any difference. Sorry if these questions sound a bit dumb but its my first 4-stroke just come off a 2002 cr250 2-stroke. (Hoping ive made the right decsion) Hope you can help thanks guys.

[_JoNeS_]

right well ive read the stickys and can't seem to find anything about the coolant leaking, not sure if this is a common thing or it has a split hose or something.

[grayracer513]

The coolant may be from the overflow tube, or from the weep hole in the right crankcase cover under the water pump. Water pump seals can harden if they sit unused for a time. The weep hole is there to allow coolant from a leaking seal to escape without the risk of contaminating the engine oil.

If it's from the overflow, it can be because the cap isn't sealing as it should, or because you let it run too long. They will normally blow off coolant if they idle longer than two minutes.

Likewise, the header will normally glow if you let it idle that long, too. But 20 seconds is too short a time, and the backfiring you describe sounds excessive. Check for an incorrectly adjusted pilot screw, air leaks around the intake, a hot start plunger that isn't closing as it should, or a partially blocked pilot jet.

[westexyzr]

Hi, first time poster here.

My '06 YZ450F does the header glowing too very quickly. Mine also pops when you let off the throttle. I decreased the popping on mine by adding HighTest octane booster. The mechanic at my local Yamaha shop told me about it. My yamaha shop stocks High Test, I guess yours might as well. Can you tell where the coolant is coming from?

[_JoNeS_]

cheers for the reply mate, Ill see what I can do. As far as were the coolant is coming from I cant tell, it was dripping off the bottom of the frame, it was coming out before the bike even fired up (as in while I was kicking her up)

[Ga426owner]

Coolant level was probably too high -

just check it after you ride it - look at weep hole also

Both 06s sound like the jetting is off and the fuel screw needs adj for temp changes

[rdefonce]

Hi, first time poster here.

My '06 YZ450F does the header glowing too very quickly. Mine also pops when you let off the throttle. I decreased the popping on mine by adding HighTest octane booster. The mechanic at my local Yamaha shop told me about it. My yamaha shop stocks High Test, I guess yours might as well. Can you tell where the coolant is coming from?

Besides the suggestions already mentioned, your bike may also need a larger pilot jet. That made a big diff with my bike. Used to run lean on low-throttle conditions, and pop on deceleration. Bigger pilot cured all that.

[bleetham]

+1 on the pilot jet. I went from the stock 42 to a 45, adjusted the fuel screw and it cleaned up everything. Slight popping on decel, which is where I wanted it. I also went up on the main jet to a 168. What a difference.

[BBrown626]

Hi, first time poster here.

My '06 YZ450F does the header glowing too very quickly. Mine also pops when you let off the throttle. I decreased the popping on mine by adding HighTest octane booster. The mechanic at my local Yamaha shop told me about it. My yamaha shop stocks High Test, I guess yours might as well. Can you tell where the coolant is coming from?

Decel popping=rich pilot. Go a size SMALLER and adjust the pilot circuit per the sticky in the jetting forum.

Do a search for "decel popping" and you will learn plenty.

[loudarbs]

Coolant issue: Just sold my '03 that sat for about 4 months without being started. When I started it up for the first time(thanks stabil, first kick) and ran it for about 1 min, shut it down, there was a very slow leak from the weep hole under the water pump. Just what Gray said, those seals tend to harden if not used for a good while.