Question about 2003 Yamaha WR 450 F

1 Answer

Slight backfire also exhaust glowing red coming out of engine

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 311 Answers

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

Posted on Feb 06, 2010

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.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
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:

2 Answers

Why does my 14 1/2 hp briggs and stratton riding mower muffler glow red after 2 min running..runs ok..just glowing red muffler.

Possible bad exhaust valve would allow burning fuel to enter muffler.
If you could do a compression test it would indicate that one cylinder is low.

Mar 11, 2016 | Garden

2 Answers

Yamaha xt225 serow front exhaust pipe glows red within 5mins of starting also running rough

Fueling issue running far to lean, choke makes the circuit richer so it will run , lean running causes over heating and serious engine damage if its running red hot, check the plug for white burnt or blistering will show lean running. Compression test to make sure the piston ring and barrel are not damaged over 110psi. Is the exhaust blocked restricted or dented ?

Mar 31, 2012 | Yamaha Motorcycles

1 Answer

Harley downpipes glowing red

Could be running VERY rich causing ignition of the exhaust gases once the second cylinder is on its exhaust cycle. This would cause both flames out of the exhaust as well as the crappy performance. Pull the plugs and see if they're dark.

Clean the plugs
If the plugs look darkened you can use the A\F mixture screw on the carbs to lean out the mixture.

To tune like this.
Find both A\F mixture screws on both carburetors.
Find out which way to spin them to lean the mixture out (for me it was to tighten them).
Using 1\8th turn adjustments do one carb at a time until it runs better\stops backfiring.
Now that it's running decently go for a spin WITH NEW PLUGS, after a good little jaunt let the engine cool and pull the plugs, if they look white you need more fuel, if they look sooty you could need to lean out the mixture 'slightly'.

Feb 16, 2012 | Harley Davidson Motorcycles

1 Answer

2007 yamaha yz450f... while riding last week it was backfiring on deceleration. it blew a 5 inch hole in the header pipe. i purchased a new one, cleaned the air filter, changed the oil and put a new spark...

Exhaust leaks near the exhaust port can draw air into pipe on deceleration and detonate any unburnt fuel leaving engine, causing backfire and high temps.
An overly lean fuel mixture on the engine can make decel backfire worse too.

Mar 13, 2011 | Yamaha YZ 450 F Motorcycles

1 Answer

Thinking of buying 1983 F150 Can start after dumping gas in the carb, will not idle, backfires through carb. Once you idle up by hand the exhaust manifold glows red, there is no converter in the...

you are getting unburned fuel into the exhaust, could be bad spark, could be engine problem, do a spark test at all the plugs, and do a compression test, exhaust valve will cause this problem,

Oct 15, 2010 | Ford F-150 Cars & Trucks

2 Answers

Hi when i start my 650 savage & leave it ticking over the manifold glows red hot & then changes to a purple colour is this the norm! rgds steve

The exhaust manafold should NOT glow red, check for intake manafold leak, this can cause a lean running condition and can lead to severe engine damage.

Nov 26, 2009 | 1990 Suzuki LS 650 Savage

1 Answer

1992 Chevrolet Suburban 1500 350 backfiring and headers glowing

You probably have a clogged up exhaust system building backpressure on the engine. Check your mufflers and catalytic convertors if you have them something is restricting the exhaust.

Sep 08, 2009 | Chevrolet Suburban 1500 Cars & Trucks

1 Answer

Exhaust glows red

sounds like it's running too lean, could be **** in the carb starving it of fuel. remove air cleaner and spray a bunch of carb cleaner in and let it sit overnight, or take carb off and strip it and clean

Apr 08, 2009 | 2004 Yamaha YZ 450 F

Not finding what you are looking for?
2003 Yamaha WR 450 F Logo

Related Topics:

301 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