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05 rm250 powervalve questions

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     I have an 2005 rm 250 and must say im now astounded with its throttle response off idle. but I have noticed the small 90 degree take off/fitting for the powervalve breather is worn/loose and keeps coming off from the brass fitting. due to its vunerable location I want this job doing right and wondered if anyone has a part number. is this a common problem and id also like to learn on how to adjust the powervalve for more top end vs more midrange and vice versa. thanks in advance again matt

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Here's where to find it. It's number 9 on the list.

 

http://www.suzukipartshouse.com/oemparts/a/suz/508b1dd7f870023530723fab/cylinder-model-k3-k4-k5-k6

 

 

The part number is 16910-09401

 

Before you adjust your powervalve, you must understand one thing. Changing the RPM that the powervalve opens does not increase or decrease peak power output. It affects the torque curve at the RPM that the valve has adjustability over. For example, let's say that the valve has the option to open at anywhere between 2500 to 3500 RPM. No matter the setting, power below 2500 and above 3500 RPM will stay exactly the same. Your choice is to find what balance works for you when it comes to how hard the power hits and how much of a flat spot you will have in the RPM range.

 

A valve set to open at a very high RPM will have the standard amount of low-end power, up until it reaches the RPM where the valve normally switched into the open position. This will create a flat spot in the rev range up until the valve opens, in exchange for a more sudden, but no bigger, rush of power compared to stock.

 

A valve set to open at a very low RPM will again, have the standard amount of power up until the valve opens when it used to stay shut. This also creates a flat spot once the valve opens, in exchange for a more manageable power surge.

 

Stock bikes are generally set up to minimize flat spots and big power surges, so the stock setting is often the most practical, but tuning the powervalve can help find the best flow of power for you.

 

To adjust the powervalve setting, find this knob on the left side of the engine. This isn't the exact one but it does the job.

 

attachment.php?attachmentid=130874&stc=1

 

To continue, loosen the two bolts that hold the knob in place, but do not take them off. In the picture it is not visible that the two bolts fasten the knob, but will be on your bike. Now, loosen the knob and turn it left until it loses the tension on the powervalve spring. You should be able to feel this. Tighten it again until you feel the spring's pressure return, then turn the knob 180 degrees further. That is the stock setting. The tighter the knob, the longer the bike waits in the rev range to switch to the open valve position. DO NOT turn the knob more than 2.5 full turns in once there is pressure on the spring, as the valve and spring will be damaged. Also, do not run the bike without any spring tension. Tighten the two bolts down after each adjustment. Be extremely careful with these bolts, as they strip excessively easy. They don't require much torque, either. It is best to put some low-strength Loctite on them and make them snug, but not tight.

Edited by 75mx125
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BUMP! 

I have an 06 manual and a single 180 degree turn is what is recommended as stock, is this the same for my 03 250? I am at 1 turn in, and notice more snap over only a 1/2 turn. I will try 2 turns tom. What is the lowest tension you can run? 1/2 turn?

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my 05 actually turns out to be an 01/02. the powervalve settings are different. stock for an 05 is 1.5 turns, the 01/02 is a quarter of a turn. ive adjusted mine accordingly now and its spot on

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