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99 ttr 250 does not run smooth during middle throttle but starts up good and wide open is good also. This is when the motor is warmed up or cold. Changed out the spark plug and cleaned out the carb. Possibly a low spark??

Posted by Anonymous on

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  • Yamaha Expert
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Did you clean the carb jets?

Posted on Feb 02, 2015

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Posted on Jan 02, 2017

  • 32 Answers

SOURCE: rebuilt carbs runs rich pops

check ur air/fuel mixture screw...turn all the way to the left and count the turns and let me know what u come up with example....1 1/4 turns 2 1/5 turns

Posted on Feb 17, 2011

dan4492
  • 8 Answers

SOURCE: 99 kawasaki ninja EX250 motor swap for a 98 NINJA EX250 MOTOR

I would try charging the battery. Take it off and put it on a slow trickle charge overnight. Batteries usually only last 3-4 years if it is an acid battery.

Posted on Feb 21, 2012

  • 22 Answers

SOURCE: my bike dies while riding

Sounds like it may be sucking air from one place or another. You may have a small hole in a fuel hose, problem with fuel filter, or just a weak connector where the tube makes a connection. Something a little more major would be a gasket under the carburetor needing replacement. Check the tubes first. A fault with gasoline that contains ethanol is that they bring on deterioration of fuel lines. This is the easiest fix.

Posted on Nov 15, 2013

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I have a F250, 5.0 1985 FUEL INJECTED Engine that will not start cold, why?


Bad coolant temp sensor. This part asks as choke on FI engines. Some older FI engines also have a cold start injector. Check to see if yours does.

Feb 23, 2015 | 1985 Ford F 250

1 Answer

Adjust carburetor yamaha 125 ttr


Hi, Anonymous if you have changed your fuel delivery system, air filter size or flow rate, mufflers or exhaust system your carburetors need re-tuning and if your fuel system (gas tank, filters, fuel valve and carburetor) is contaminated with ethanol sludge, varnish, rust, dirt, water etc. or your bike has been sitting for months or years without running these components must be "PROPERLY" cleaned and reassembled "CORRECTLY" before any adjustments can be made. Tuning your carburetor is fairly simple once you understand the basic principals. You engine is a simple airbox sucking air in and blowing it out, it is finely tuned at the factory for maximum performance once you upset that delicate balance by changing air filters, camshafts or exhaust systems your performance may go down the and the engine may run poorly, you need to compensate the air-fuel mixture in the carburetor in order for the engine to run smoothly and at peak performance. If you are running multi carburetors you need to sync them first and make sure your air cleaner element is clean and dry for paper elements or lightly oiled for foam and meshed elements and properly installed. Here is how and where you compensate trouble: "TIP" if your engine "BOGS" your not getting enough fuel.
1. Closed to 1/8 throttle is managed by the air screw and pilot/slow jet.
2. 1/8 to 1/4 throttle is managed by the air-screw, pilot/slow jet, and throttle slide.
3. 1/4 to 1/2 throttle is managed by the throttle slide and jet needle.
4. 1/2 to 3/4 throttle is managed by the jet needle, needle jet, main jet, and air jet.
5. 3/4 to wide open throttle is managed by the main jet and air jet.
6. Wide open throttle is managed by the main jet.
If you are running lean, spark plug electrode color is white, engine runs hot and feels like it is starving for fuel you need to go up on the jet size or move the c-clip down one notch. If you are running rich, spark plug color is black or dark gray, engine runs cool, and bogs down when accelerating you need to go down on jet size or move the c-clip up one notch. When your carburetor is properly tuned for maximum performance your spark plug electrode will be a light tan color like coffee with cream. If you prefer fuel economy over performance you can go down on main jet sizes until a satisfactory level of lower performance is acceptable versus MPH, your spark plug color will be whiter and your engine will run warmer. These tuning adjustments will only make improvements if your intake and exhaust system have no air leaks or sealing issues and the entire electrical system is in proper working order and you have no mechanical issues. For more information about your issue and valuable "FREE" downloads that you will need please click on the websites below. Good luck and have nice a day.
Stock TTR125 Carb Screw Settings TTR
Ttr 125 Carb Idol settings
http://www.yamaha-motor.com/assets/service/manuals/2007/LIT-11626-20-01_ttr125all_1961.pdf
OEM parts for Yamaha
http://mybikemanuals.com/yamaha/yamaha-tt-owners-manuals

Jun 21, 2014 | 2006 Yamaha TTR 125 E

2 Answers

1996 honda will not start under 60 degrees


tune it up. (fresh spark parts work best in cold and for sure damp wheather.
fresh gas?
leaking injectors?
isc stuck closed, and rpm low, hot?

the ecu, anticipates the next cold start,
it knows how much to open the iSC valve, to get a good start cold
and if colder to day, it opens more. (math)
if it (ISC) is gummed up,fas all do, it cant start right
so next time, try %10 throttle, starting, emulating a good ISC.
see?

Jan 07, 2014 | 1996 Honda Accord

1 Answer

My Yamaha 250 zeal has a problem starting. it turns over fine but often wont continue running while cold, it doesn't like choke and stalls if the throttle is eased open. until it has warmed up.


Hi, Barry and the usual suspects are:
1. Fuel cap or fuel tank is not venting properly.
2. Fuel filter clogged.
3. Fuel line pinched or kinked.
4. Float needle and seat sticking.
5. Float level too low.
6. Carburetor bowl vent line clogged/blocked/pinched.
7. Idle adjusting screw set too low.
8. Air/fuel mixture screw set too lean.
9. Idle port, transfer ports, slow air jet clogged.
10. Slow fuel jet clogged.
11. Faulty fuel pump.
For more information about your issue and valuable "Free" downloads that you will need please Click on blue links below. Good luck and have a wonderful day.
Yamaha zeal 250 stalling and problem with warm starting
1999 Yamaha Zeal aka FZX 250 will not idle
https://netrider.net.au/threads/looking-for-a-fzx250-zeal-service-manual.102959
OEM parts for Yamaha
Manuals Data Zealous

Jul 21, 2012 | Yamaha FZX 250 Zeal Motorcycles

1 Answer

I would like to know what the factory high and low settings are on carb mantis 2 cycle there are no plastic caps on my jet screws and need to know how many turns out ...


After seating the screws back them out 1 1/2 turns. This should be close enough to get it started. Let the motor warm up a little then, with it idling, turn the low screw in until it starts having a hard time running then back it out until it idles smoothly. Prop up the Mantis so it can run at full speed safely while you adjust the high side. With the throttle wide open, again turn the high screw in until it starts running roughly and back it out until the motor is running smooth. Some say to turn the screws out until the motor starts having a hard time running and then turn it back in half way to where it was running bad at the other end. This doesn't work as some engines don't care how far open the screws are.

May 26, 2011 | Mantis 2-Cycle Tiller

2 Answers

2001 yamaha ttr 250, starts, idles ok, bogs at acceleration


Has the bike been stored for any long length of time?
old fuel in the carburetor will turn to a varnish like residue blocking the jets,or possibly water in the carburetor.

May 03, 2010 | 2002 Yamaha TT-R 250

3 Answers

Hello I have an 98 yz 250 it will not start when cold I can give it a shot of gas in the air box and it fires rite up and will restart as long as its warm and runs great but will not once its cooled down...


Sounds like you have a carburator issue.
The choke richens (Adds more fuel) to allow a cold start. Have the carb checked by someone with an idea of what to look for. Make sure all passages are clean and clear.
Do a compression test, throttle wide open , you should have at least...at least 100psi to run, but yours should be higher with a new top end.

Mar 30, 2010 | 2003 Yamaha YZ 250

2 Answers

Carb


make sure the air filter is clean if it is then take your carb off and clen out your main jet large brass jet in center of the bottom of the carb if that does not fix it adjust your air screw on side of carb brass flat head screw turn right until tight lightly not to hard just enough till it feels snug then start at one turn left and rev 2-3 times then go a 1/4 turn left at a time till the bike revs and runs well good luck

Jun 28, 2009 | 2002 Yamaha TT-R 250

1 Answer

I get it started it runs as long as you have it wide open but you let of the gas it dies


This might require adjustment of the hi speed carb screw, the lo speed, and the idling screw as well.
The engine needs to be good and warm, you need to be certain you have a fresh fuel mixture in the tank, and you should check the air filter because it too affects the way the saw will run at low speed and idle.

I would start with the hi speed adjustment screw since wi does start. Fire it up and run it a bit to make sure you have it warmed up.

You may need someone else to help you hold the saw while you make these adjustments. With the throttle wide open, turn the hi speed screw slowly, in increments of 1/4 turn, to the left. It may be just a bit off. The objective here is to turn one way until it sputters or runs a little rough. Then turn it the other way until the engine smooths out. Continue to turn in the same direction until it again runs rough. Then turn back about halfway between those two points.

It should run well at wide open throttle. Place your screwdriver in the low speed adjustment screw and turn to the left, in small 1/4 increments like you did before. The objective here is to adjust to the point where the saw will throttle up quickly and smoothly, and more and more from an idling position, or as close as you can get.

If you find you don't get that, and the ramp up is choppy and unsmooth, adjust in the other direction. Eventually you should get to a point where you have quick response to your throttle. You should get to a point where it runs without being wide open.

If it fires up easily and throttles up smoothly but won't idle, the you need to adjust the idling screw. Adjust it until the chain begins to move on the bar when you let the throttle go. Once you get to the point where it idles with the chain moving, back off the adjustment until the chain just stops moving.

Make sure the air cleaner is clean. You may have to clean the carb with spray carb cleaner while it is running at full throttle. If you do, spray a tiny bit at a time, as it will almost kill the engine.

Finally, after all this work, invest in a new spark plug, even if the one in it isn't that old.

Sirwriter

Jun 15, 2009 | Garden

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