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Discussion Starter #1
Hi, I have a 99 venture 500 that seems to "cruise at 5500 rpm"(what I call shift speed corrrect me if im'mistaken) when you give throttle it seems to bog a bit until 6500rpm and then it has power galore. My theory is that it is shifting too low and is not running in its power range. Can anyone give me some ideas and rpm shift speeds that they have on your sleds?
 

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that sled at full shift should hit 7800 rpm, thats your peak power range. if your bogging when you pin it at 5500, it sounds like the sled is not backshifting quick enough and temporarily loading the motor down. could be worn belt, dirty clutches, or not enough preload on the secondary spring, or just some minor clutch tweaks. hard to pinpoint one specific item without being there. i would first validate the condition of both clutches and their components, as well as the cleanliness. then inspect the condition of the belt, or even try a new belt. while your inspecting things, see if you can document what you have in your clutches like spring color in each, weights, helix, etc. what altitude are you riding at?
 

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Discussion Starter #3
I'm not sure of the altitude. I live in southern ontario Canada. The sled has always, to my knowledge, been around here. I have two belts ,both seem very loose and have lots of slack. I will be purchasing a new belt.What about the secondary plastic "ramps"? What is their function on clutch performance? They are cheap and I will install those too as maintenance but still wonder their purpose(does the thickness matter ,or is it just rail to slide on). my peak rpm is approx 7800 .How can i check secondary spring tension? Is there and adjustment for tension(multiple holes)? Thanks Yamadad4 for all your help.
 

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those ramps are a designed wear part and basically keeps the helix from rubbing the sheave. there is a minimum wear spec. the preload of the spring is set using the optional holes in the helix and the sheave. for example, the helix will have a 0, 3, 6 and 9. the sheave has a 1,2 and 3. let say for instance your sled is supposed to be set at 60*. for this, you would have the tab on the spring in each of the 3 holes. 3 +3 =6 x 10 =60. for 70 you would do 6 and 1. the more preload the slower the upshift and the more the engine will rev. less preload will make the sled shift out faster and may bog the engine. lower numbers=less preload, higher = more.
 

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Discussion Starter #5
Great info, I ordered a belt, secondary spring and ramp bushings.The belt is $30.00 more than the most expensive belt yamaha stocks . They keep most belts in stock but not this one. Perhaps the belts I have are both wrong? I asked them to look up the belt by serial # instead of model listing and thats what came up. The serial # is 8CY-c0117.
 

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Discussion Starter #6
took my secondary apart, sheave was set at 1. Helix set at 6. I dont understand the mathematics you gave. how would I increase the preload. The paint on the spring was pinkish/red.
 

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6 and 1 would be 70 degrees. 6+1 x 10= 70. you should be at 80, or 6 and 2. there is a bit of a trick to wind the helix and spring but it becomes self explanatory after a few tries. not sure if the belt # was a typo, but i have been playing with yamaha sleds for over 30 years and have never ran across an 8CY. 8CH, 8CJ, as well as a host of others. your sled should be the 8CH, or even a properly set up 89L or 87X. close in length, different compounds.
 

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Discussion Starter #8
The serial # of the sled is 8CY-C0117. I checked the belts. I have 1, 89L-17641-01 and a 8CH-17641-00. I am unsure of the part # of the new belt they ordered for me. I am getting all my parts tomorrow and will take the old ones to compare. I will also set up my secondary to 80 and give it a try. Thanks again for all your help
 
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