I'm having some issues with the power valves on my 98 SRX 700 and as I took them out to inspect and troubleshoot them I had several questions.
In trying to better understand how the power valves work here are some of the questions that I have:
1a) When the servo motor actuates (pulls back the valves) what determines how far the servo motor shaft turns, thus how far the cables are pulled? Are there internal switches within the servo motor?
1b) Same question as 1a accept on when the servo motor unwinds and allows the valves to spring back into the exhaust what determines when the servo motor stops?
2) I believe I've read that it is a common problem for the cables to pull out from the valve and that there are people or shops out there that will replace the end of the valve where the cable attaches. Stock this part of the valve is aluminum and these aftermarket people/shops replace that end either with carbon steel or stainless steel. I read Hauck Power Sports does this and if I'm not mistaken it sounded like they use carbon steel. Then I read about somebody who is active (or used to be active) on this Totallyamaha forum who used stainless steel. Anybody know if this person is still around and still doing this mod for people?
3) I've seen some youtube videos for adjusting the power valves. The person used two 2.5 mm allen wrenches to adjust the cables/valves properly. Somebody else commented that may be a bit tight and 3 mm wrenches may be better. Thoughts on 2.5 vs 3 mm wrenches to use? Also, in the video it was mentioned that if you turn the idle down below 900 rpm the servo motor does something. What does the servo motor due when the idle is lowered below 900 rpm? What/where do I adjust to change the idle? I assume it must be on the carb.
4) This one is theoretical. Does anybody know how the SRX 700 engine would run with the power valves in the full open position all the time? I'm a big fan of the KISS principle (Keep it simple stupid) and I'm just curious. I'm thinking like connect the valve to a blank plate that bolts up to the cylinder such that the valve is inserted but in the full open position all the time, thus eliminating the complexity of the servo motor and cables. Would this engine be really poor in the lower rpm range with the valves full open? Would there be any jetting concerns in the lower rpm range since you are essentially changing the exhaust resistance/back pressure. Part of me says I'm OK with a bit of reduced power/efficiency at lower rpms. If I really want to go I'm going to give it enough throttle to get rpms above where the power valves would open anyhow.
5) What rpm are the power valves supposed to open up at?
I think that's it for now. Sorry for the long and wordy post and some of the newbie type questions. Any thoughts/answers you may have regarding these questions would be much appreciated. Happy Sledding!
In trying to better understand how the power valves work here are some of the questions that I have:
1a) When the servo motor actuates (pulls back the valves) what determines how far the servo motor shaft turns, thus how far the cables are pulled? Are there internal switches within the servo motor?
1b) Same question as 1a accept on when the servo motor unwinds and allows the valves to spring back into the exhaust what determines when the servo motor stops?
2) I believe I've read that it is a common problem for the cables to pull out from the valve and that there are people or shops out there that will replace the end of the valve where the cable attaches. Stock this part of the valve is aluminum and these aftermarket people/shops replace that end either with carbon steel or stainless steel. I read Hauck Power Sports does this and if I'm not mistaken it sounded like they use carbon steel. Then I read about somebody who is active (or used to be active) on this Totallyamaha forum who used stainless steel. Anybody know if this person is still around and still doing this mod for people?
3) I've seen some youtube videos for adjusting the power valves. The person used two 2.5 mm allen wrenches to adjust the cables/valves properly. Somebody else commented that may be a bit tight and 3 mm wrenches may be better. Thoughts on 2.5 vs 3 mm wrenches to use? Also, in the video it was mentioned that if you turn the idle down below 900 rpm the servo motor does something. What does the servo motor due when the idle is lowered below 900 rpm? What/where do I adjust to change the idle? I assume it must be on the carb.
4) This one is theoretical. Does anybody know how the SRX 700 engine would run with the power valves in the full open position all the time? I'm a big fan of the KISS principle (Keep it simple stupid) and I'm just curious. I'm thinking like connect the valve to a blank plate that bolts up to the cylinder such that the valve is inserted but in the full open position all the time, thus eliminating the complexity of the servo motor and cables. Would this engine be really poor in the lower rpm range with the valves full open? Would there be any jetting concerns in the lower rpm range since you are essentially changing the exhaust resistance/back pressure. Part of me says I'm OK with a bit of reduced power/efficiency at lower rpms. If I really want to go I'm going to give it enough throttle to get rpms above where the power valves would open anyhow.
5) What rpm are the power valves supposed to open up at?
I think that's it for now. Sorry for the long and wordy post and some of the newbie type questions. Any thoughts/answers you may have regarding these questions would be much appreciated. Happy Sledding!