Question about 2003 Yamaha YZ 250

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92 yz 250 hard to start and woulnt full accelarate

My bike has a lot of compression and is a pain to crank but when it does its a power house until u try to open it up it bogs out around mid range. after third gear it docent seam as bad. what could it be. its not the plug ive tried that.

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I may be wrong but it sounds like your bike has either,a dirty air filter(this would explain the bogging out in the midrange) or a bit of crud in the carb,check the tank filter(the one that is incorporated in the fuel tap),then get the carb off and give all the jets a good clean out,it only takes a small amount of dirt in the fuel system or carb to seriously affect performance,while you have the carb off,take off the inlet manifold that holds the carb,remove the reed valve block and check the condition of the reeds(if you can see daylight through the valve seat)ie between the reed valve and the base block,the reeds may need replacing,this may also explain your hard starting,as the reeds need to fully close against the block to get the right amount of air/fuel through to the crankcase,.these bikes generally go like a rocket so it will only be something minor which is stopping you enjoying it to its fullest..hope this helps

Posted on Jul 23, 2009

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Hi ive got a 2003 rm 250 ive just changed the crank shaft seal and the bike is still smoking but not as bad cud i have oil in my packing in my back box of my exhaust or have i another problem? And the bike...


I would suggest doing a compression check and checking the results against your manual (should be at least 165PSI or so. Low compression will make the bike run rich which would make it smoke excessively. It would also make it hard to start and run poorly with low power. New rings could do wonders.

Scott

Feb 23, 2011 | 2003 Suzuki RM 250

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I have a 1999 yz 250, I was wondering can you put a compression release or hot start on my bike? I am a small guy and I broke my ankle not long ago so it's almost impossible to start.. My email is...


A 1999 YZ 250 is a two sroke, it is not possible to add a compression release or a hot start, those are on four strokes. (In 1999 it's a YZF400)

Mar 13, 2010 | 2003 Yamaha YZ 250

1 Answer

2004 YZ 250 4 STROKE PROBLEMS STARTING


There is a proper way to start the engine. Four controls are on your bike to assist in starting. Below are generic instructions.
  • The choke, used when the engine is cold. Pull the red knob for choke.
  • The " Hot Start " Lever, used when the engine is hot. Pull the lever to lean the fuel mix when the engine has been running.
  • The de-compression lever, always used.
  • The throttle, used to prime the cylinder, (power valve).
Don't kick, instead, push the kick lever downward. You will feel the back pressure as the piston is going upward on the compression stroke to the point the pressure is great enough that the kick lever "locks up". You are very close to TDC. NOW, pull in the de-compression lever. Push the kick lever a little bit more to get the piston past TDC. Now release the de-compression lever. Give the throttle a 1/4 turn then let it snap closed. A diaphragm, (Power valve), in the carb gives a shot of gas when this is done. DO NOT do this multiple times because you will flood the engine. Leave the throttle closed when kicking. A flooded engine will often backfire. Now give a strong kick through the full sweep of the kick start lever. Quickly get your foot off the kick lever at the end of the kick to avoid any chance of "kickback" from the kick lever. This happens in the case of a misfire, aka > backfire. It can be very painful, and can even break a leg. I am serious about that. Repeat the process (but without the throttle priming), for six kicks. After six kicks go ahead and twist the throttle again for a second priming. A good battery, a clean spark plug, a clean carb and clean air filter will also aid in starting. Note that not all carbs have a power valve. When a power valve is not present you should crack the throttle open only 1/8 inch from closed on each kick.

Go to this site and you can download a free PDF service manual. The site may take up to 20 seconds to load the complete list of manuals. Yours is on the list.
www.carlsalter.com/motorcycle-manuals.asp

Nov 19, 2009 | 2004 Yamaha YZ 250 F

1 Answer

How i start my yz426 2002 yamaha the bike has a good compresion the carbulator true gas and the spare plug is good


these bikes are the hardest bikes to fix, easiest thing, kick the bike super slow until you piston is at TDC, you will know because it will be hard to kick, then pull the compression release down and as you start to kick release the compression release. NOT an easy task starting a 426 but good luck

Nov 02, 2009 | 2002 Yamaha YZ 426 F

1 Answer

2007 honda crf 250 r hard starting when cold ,


There is a proper way to start an engine. Most bikes have four controls to assist in starting.
  • The choke, used when the engine is cold. Pull the red knob for choke.
  • The " Hot Start " Lever, used when the engine is hot. Pull the lever to lean the fuel mix when the engine has been running.
  • The de-compression lever, always used.
  • The throttle, used to prime the cylinder.
Don't kick, instead, push the kick lever downward. You will feel the back pressure as the piston is going upward on the compression stroke to the point the pressure is great enough that the kick lever "locks up". You are very close to TDC. NOW, pull in the de-compression lever. Push the kick lever a little bit more to get the piston past TDC. Now release the de-compression lever. Give the throttle a 1/4 turn then let it snap closed. A diaphragm in the carb gives a shot of gas when this is done. DO NOT do this multiple times because you will flood the engine. Leave the throttle closed when kicking. A flooded engine will often backfire. Now give a strong kick through the full sweep of the kick start lever. Quickly get your foot off the kick lever at the end of the kick to avoid any chance of "kickback" from the kick lever. This happens in the case of a misfire, aka > backfire. It can be very painful, and can even break a leg. I am serious about that. Repeat the process (but without the throttle priming), until the bike starts. Go ahead and give it another primer shot after the 5th kick attempt. A good battery, a clean spark plug, a clean carb and clean air filter will also aid in starting.

Sep 23, 2009 | 2005 Honda CRF 250 R

1 Answer

Yz 250


yz 250 two strok. measur your compresion. gas leak valve gasket cilinder. of your exhaust pipe full whit carbon. a good running 2stroke have a lot of power in al the gears. when is your last inspection of the engine? j kerkhof

Aug 02, 2009 | Yamaha YZ 250 Motorcycles

2 Answers

VERY hard starting takes way to many kicks usually play out befo


There is a proper way to start the engine. Four controls are on your bike to assist in starting.
  • The choke, used when the engine is cold. Pull the red knob for choke.
  • The " Hot Start " Lever, used when the engine is hot. Pull the lever to lean the fuel mix when the engine has been running.
  • The de-compression lever, always used.
  • The throttle, used to prime the cylinder.
Don't kick, instead, push the kick lever downward. You will feel the back pressure as the piston is going upward on the compression stroke to the point the pressure is great enough that the kick lever "locks up". You are very close to TDC. NOW, pull in the de-compression lever. Push the kick lever a little bit more to get the piston past TDC. Release the de-compression lever. Give the throttle a 1/4 turn then let it snap closed. A diaphragm in the carb gives a shot of gas when this is done. DO NOT do this multiple times because you will flood the engine. Leave the throttle closed when kicking. Give a strong kick through the full sweep of the kickstart lever. Quickly get your foot off the kick lever at the end of the kick to avoid any chance of "kickback" from a backfire. It can be very painful, and can even break a leg. I am serious about that. Repeat the process (but without the throttle priming), until the bike starts. A good battery, a clean spark plug, a clean carb and clean air filter will also aid in starting.

Top rating for this answer? Thanks!

Jun 11, 2009 | 2003 Yamaha YZ 250 F

1 Answer

2005 250 f 65 kicks to start


Several things can cause the problem. First, spring for a new spark plug. The stock plug is NGK CR8E. Now the plug is eliminated as a problem. Next, pull the slide out of the throat of the carb. Now remove the jet needle. Put the needle clip on the 4th notch, (this is the stock setting). Use only premium gas. Next, follow the starting instructions below.

There is a proper way to start the engine. Four controls are on your bike to assist in starting.
  • The choke, used when the engine is cold. Pull the red knob for choke.
  • The " Hot Start " Lever, used when the engine is hot. Pull the lever to lean the fuel mix when the engine has been running.
  • The de-compression lever, always used.
  • The throttle, used to prime the cylinder.
Don't kick, instead, push the kick lever downward. You will feel the back pressure as the piston is going upward on the compression stroke to the point the pressure is great enough that the kick lever "locks up". You are very close to TDC. NOW, pull in the de-compression lever. Push the kick lever a little bit more to get the piston past TDC. Give the throttle a 1/4 turn then let it snap closed. A diaphragm in the carb gives a shot of gas when this is done. DO NOT do this multiple times because you will flood the engine. Leave the throttle closed when kicking. Release the de-compression lever and give a strong kick through the full sweep of the kick start lever. Quickly get your foot off the kick lever at the end of the kick to avoid any chance of "kickback" from a backfire. It can be very painful, and can even break a leg. I am serious about that. Repeat the process (but without the throttle priming), until the bike starts. A good battery and clean air filter will also aid in starting.

This will likely tame the beast for you. Please rate this answer. Thanks!

Jun 06, 2009 | 2003 Yamaha YZ 250 F

1 Answer

Oil leak


With a ten year old 250 cc engine that has been ridden a lot you should be prepared to rebuild the motor. If you have to have someone else do it the bike is probably not worth the cost. If you can do it yourself the parts can be bought for less than $400 and installed in a day.

Feb 22, 2009 | 1999 Honda XR 250 R

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