air fuel mixture - Motorcycle Forum
Motorcycle Forum

Go Back   Motorcycle Forum > Manufacturers > Yamaha



Reply
 
Thread Tools
Old 02-21-2009, 11:58 AM   #1
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default air fuel mixture

is there an easy way to tell if the air fuel mixture is running rich or lean? I have an 85 maxim 700 and to me it smells like it is rich but I don't want to screw anything up and be forced to take it to a shop. It starts and runs ok once it is warm just smells rich.

Thanks
jim_jen_dj is offline   Reply With Quote

Advertisement [Remove Advertisement]
Old 02-21-2009, 12:46 PM   #2
Badlands-4-2
Super Moderator
 
Badlands-4-2's Avatar

Join Date: Oct 2008
Location: The Badlands of North Dakota
Posts: 10,364
Badlands-4-2 has a spectacular aura about
Default

The easiest way is to pull the plugs. Black = rich / whaite = lean and a light tan = just right.
Badlands-4-2 is offline   Reply With Quote
Old 02-21-2009, 12:55 PM   #3
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

okay just went and checked and they are black so what would be the next thing to do?

and thanks
jim_jen_dj is offline   Reply With Quote
Old 02-21-2009, 02:28 PM   #4
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

Also I got the numbers off of my spark plugs the are from NGK and the numbers are bp8es, do I need to go to a "hotter" plug, i dont want to fry my engine though. Or should I work on my air/fuel mixture.
jim_jen_dj is offline   Reply With Quote
Old 02-21-2009, 03:28 PM   #5
rexmitchell
Administrator
 
rexmitchell's Avatar

Join Date: Jan 2008
Location: THE ATX
Posts: 14,779
rexmitchell has a spectacular aura about
Default

Does your bike have any kind of smoke coming out of the exhaust?
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


You may all go to Hell, and I will go to Texas. - Davy Crockett
rexmitchell is offline   Reply With Quote
Old 02-21-2009, 03:37 PM   #6
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

I'll say yes due to the fact that it is like 20 degrees here but the only thing I think is wierd is when I shut off the bike there is still some exhaust that comes out of the tail pipe. But other than that it is not excessivly smoking or any odd colors it just smells rich
jim_jen_dj is offline   Reply With Quote
Old 02-21-2009, 04:00 PM   #7
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

Before I do this I want to get everything straight. To me I would turn the mixture screws clockwise to "tighten" them thus making the mixture leaner, is this correct or is it the other way around. Also common sense would tell me go in small amounts as to not go too rich or lean. any added tips would be very helpful.


Also should I only do one at a time or do all of them at once ( it is an inline four )

Thanks to all
jim_jen_dj is offline   Reply With Quote
Old 02-21-2009, 04:09 PM   #8
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

One more thing popped into my head should all the screws be the same level or will they all be different? I noticed that some were a little deeper than others. Could that be the issue?
jim_jen_dj is offline   Reply With Quote
Old 02-22-2009, 08:45 AM   #9
Dennis in NH
Rough Writer
 
Dennis in NH's Avatar

Join Date: Sep 2007
Location: Southern NH
Posts: 1,011
Dennis in NH is on a distinguished road
Default

I don't know how to adjust the 700 Maxim but I know that if it's running lean, you will hear exhaust popping and (I think) backfiring.

Dennis
Dennis in NH is offline   Reply With Quote
Old 02-22-2009, 09:14 AM   #10
CB750F
Shantytown Mayor
 
CB750F's Avatar

Join Date: Jul 2006
Location: Huntingdon Co, PA
Posts: 4,722
CB750F is on a distinguished road
Default

Before you do anything else wait until it warms up to see what happens. It might correct its self. my 4 wheeler runs a little on the rich side when it's cold compared to hot. I almost never have the Ninja out unless it's above 40. Probably a good tune and carb sync is all it needs IMO if it runs rich when the temps go up.

Usually the mixture screws are 1.5 to 2.5 turns out.
__________________
07 Ninja 500
98 ZX6E
CB750F is offline   Reply With Quote
Old 02-25-2009, 08:08 PM   #11
skooter Bum
Senior Member

Join Date: Sep 2008
Location: Warren, Michigan
Posts: 1,280
skooter Bum is on a distinguished road
Default

jim_jen_dj,

Did you start to have a problem have you put gas in the bike?

What kind of weather (temperature wise) are you riding in?

If your riding in cool temp's your bike is going to take longer to reach normal operating temperature, maybe 3 times longer. Which means you might have the choke on longer than you would normally do which could cause the samething.

Don't put hotter plugs in the bike. If you do have a fuel problem (carbs), putting hotter plugs in it isn't really going to help any. If you replace the plug's use stock.

When the bike warms up, how does it run? What is your gas mileage like?
In cooler weather it's going to drop some. If the plugs were black, what did the electrodes look like?

Before you touch the carb's, try running some fuel cleaner through the carbs first. If that doesn't work, then you might have problems with the carb's and adjusting them really won't do you any good.

If the carb's need to be gone through, they'll have to be synchronize to make sure that they work together. If you set them up wrong,....you'll have a whole other set of problems.

Good Luck and let us know how it turns out.

Last edited by skooter Bum; 02-25-2009 at 08:11 PM..
skooter Bum is offline   Reply With Quote
Old 02-27-2009, 09:16 AM   #12
jim_jen_dj
Verified

Join Date: Feb 2009
Posts: 50
jim_jen_dj is on a distinguished road
Default

Quote:
Originally Posted by skooter Bum View Post
jim_jen_dj,

Did you start to have a problem have you put gas in the bike?

What kind of weather (temperature wise) are you riding in?

If your riding in cool temp's your bike is going to take longer to reach normal operating temperature, maybe 3 times longer. Which means you might have the choke on longer than you would normally do which could cause the samething.

Don't put hotter plugs in the bike. If you do have a fuel problem (carbs), putting hotter plugs in it isn't really going to help any. If you replace the plug's use stock.

When the bike warms up, how does it run? What is your gas mileage like?
In cooler weather it's going to drop some. If the plugs were black, what did the electrodes look like?

Before you touch the carb's, try running some fuel cleaner through the carbs first. If that doesn't work, then you might have problems with the carb's and adjusting them really won't do you any good.

If the carb's need to be gone through, they'll have to be synchronize to make sure that they work together. If you set them up wrong,....you'll have a whole other set of problems.

Good Luck and let us know how it turns out.
Well, I don't have the &%^$ to ride when it is below 40 or 50 so it has not been that much, also I don't know the milage yet just because of that fact. But when the bike gets totally warmed up it runs great, so should I assume there is no problem or should I still run some cleaner through it?

Thanks
jim_jen_dj is offline   Reply With Quote
Old 02-27-2009, 11:26 AM   #13
skooter Bum
Senior Member

Join Date: Sep 2008
Location: Warren, Michigan
Posts: 1,280
skooter Bum is on a distinguished road
Default

Your fine. You don't have to put any cleaner in the fuel.
skooter Bum is offline   Reply With Quote
Old 07-18-2010, 04:36 PM   #14
Jinxie
Motorcyclist

Join Date: Jul 2010
Posts: 13
Jinxie is on a distinguished road
Default

I have a follow up question... I feel as if I am having a similar problem.

I have a 1981 Kawasaki 440LTD that runs great. It has no problem going down the road but its top speed is only about 65. It has a hard time staying at 65 and also only gets about 35 miles to the gallon. Any ideas?
Jinxie is offline   Reply With Quote
Old 07-19-2010, 11:35 AM   #15
skooter Bum
Senior Member

Join Date: Sep 2008
Location: Warren, Michigan
Posts: 1,280
skooter Bum is on a distinguished road
Default

When was the last time it was tuned up?
skooter Bum is offline   Reply With Quote
Old 12-28-2010, 02:04 AM   #16
cppursell
Newbie

Join Date: Dec 2010
Posts: 4
cppursell is on a distinguished road
Default

Good advice, thanks. I just got my first bike and want to tune it up, and will look at the spark plug.
cppursell is offline   Reply With Quote
Old 12-28-2010, 09:26 AM   #17
weekendrider
Senior Member

Join Date: Sep 2008
Location: Tin Town, MO
Posts: 203
weekendrider is on a distinguished road
Default

Before you start pulling the plugs to make adjustments.
Take the time to google "throttle chops" and the correct way to get a good plug reading.
If you want a reference for what the plugs are showing. Dan has a great site and his plug reference works well for me.
http://www.dansmc.com/spark_plugs/sp...s_catalog.html

For understanding CV carbs and how they work. This was written by some serious XS'ers about the CV carbs used on the XS650. BUT the information is a good reference for Constant Velocity carbs.
http://www.amckayltd.com/carbguide.pdf
__________________
250 Savage,XS650 x 3,FXDC,XV250
weekendrider is offline   Reply With Quote
Reply
Thread Tools


All times are GMT -4. The time now is 10:39 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.