Question about Yamaha WR 450 F Motorcycles

1 Answer

I have a 2003 Model Yamaha WR 450. The bike has been sitting for some time now and trying to get it going again. The problem I am having is that when I start it the bike is getting very hot very quickly (To the point the exhaust starts to glow red) and then it back fires badly. Can you please let me know what the possible causes could be and where to start. Thanks

Posted by on

  • torben481 Jul 30, 2009

    I am not sure re the exhaust. I can remove it and see how it runs without the exhaust.

    The timings has not been touched since it came from factory and bike has done virtually no mileage.

    Is there any chance it could be running too lean? Maybe problem with jet or fuel setting?




1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that gotĀ 5 achievements.


    An expert who has written 50 answers of more than 400 characters.


    An expert whose answer gotĀ voted for 20 times.

  • Expert
  • 123 Answers

Is the exhaust blocked?? Has any timing adjustments been made to the bike while it was laid up?? It really does sound like the exhaust is blocked causing the fumes to build up leaving unburnt fuel in the pipe and then the fuel burning the pipes. Ian

Posted on Jul 30, 2009

  • Ian Percy Jul 30, 2009

    But if it`s not been touched since you laid it up, I wouldn`t touch the fuel system, they`re a nightmare to reset, believe me. Ian

  • Ian Percy Jul 30, 2009

    Have you tried new fuel, the old fuel will have gone off now. Ian



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
New users get 2 Free calls (no credit card required) and instant help on almost anything you can think of (from cars to computers, appliances, handyman, and even pets).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How do I time my 2003 wr450 water pump gear?

Hi, Kurtroberts8 there is no water pump gear timing just bolt it in for more information about your question and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
YAMAHA WR450F Owner Service Manual
OEM parts for Yamaha
YAMAHA WR450F Owner Manual
Yamaha WR 450 2004
Yamaha WR450F Wikipedia

Jun 20, 2011 | 2003 Yamaha WR 450 F

1 Answer

I have a yamaha yfz 450 and sometimes the oil label is full and sometimes is empty

Not sure what you mean by oil label, but...In your owners manual is a procedure to check the oil level. You run it to get it up to temperature, then shut it off. Let it sit for close to three minutes, and then with the bike level, check your oil.

Mar 05, 2011 | 2005 Yamaha WR 450 F

1 Answer

G'day,i have a 05 wr 450, when out riding my battery went flat, the old girl still had balls for a while then i lost it , felt like she was missing, would the batt cause the the bike to lose power ?...

charging system has failed. In that case, the battery will run the bike until it's dead. If you can shut off your headlight, it my go a bit farther, but you need to fix the charging system.

Aug 22, 2010 | 2005 Yamaha WR 450 F

1 Answer

Glowing RED exhaust pipe

try a bigger jet or its going to cause some damage. You can pull the choke on to get some more fuel in to cool it .
Check that the cam timing hasnt been played with, some change the exaust cam by a tooth to copy yz specs, on top dead centre, there is a little arrow on each cam that lines up with the rocker cover surface

Mar 09, 2010 | 2003 Yamaha WR 450 F

1 Answer

How do i ajust the mixture on my wr 450 03 model people tell me it is to rich

the quick fix is to lower the needle by a notch, you need to pull the top off the carb and remove needle then raise the little circlip up to the next groove which will lower the needle and let less fuel through.
this may help some but it depends on when the bike runs rich as there are a number of jets that can be swapped to change mixture settings

Feb 20, 2010 | 2003 Yamaha WR 450 F

1 Answer

Slight backfire also exhaust glowing red coming out of engine

your bike sounds like it is running way to lean in the carb ,i would not run it at all until you get it sorted,the engine is going to destroy itself if you leave it the way it is...cheers

Feb 04, 2010 | 2003 Yamaha WR 450 F

1 Answer

I have a 2005 YZF 450. Can I put on a electric

I think that the WR version has electric start, but it may require that the engine cases be changed, pricey!!! Not to mention wiring, battery, and on.

Jul 01, 2009 | 2003 Yamaha YZ 450 F

1 Answer

Hesitation problems 2003 yamaha wr 450 f

sounds like a jetting issue. change the main jets starting from the largest one you own and work your way down.

Dec 14, 2008 | 2003 Yamaha WR 450 F

Not finding what you are looking for?
Motorcycles Logo

Related Topics:

106 people viewed this question

Ask a Question

Usually answered in minutes!

Top Yamaha Experts


Level 2 Expert

281 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1144 Answers


Level 3 Expert

2600 Answers

Are you a Yamaha Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides