Need info for Decker pipes/650
- Thread starter xc6rider
- Start date
Here is some specs I somehow saved from a while back when I was going to do a 600/650 swap into a 400 chassis I had. I got a set of decker pipes with a pile of 600/650 parts I had. Here's the info from an e-mail I received from Decker:
"It’s unlikely that the pipes are actually 600 pipes although they may be. We did build 600 pipes but built many more 650 pipes which will work better then the actual 600 pipes. The only way to know they are our pipes is that they would have our stamping on them and if the exhaust header flange hasn’t been changed we did put markings on them as well but they get hard to see after time as they were put on with an electric scribe. As for tuning, I don’ have any info on the 600’s but for the 650’s we took the foam out of the air box and started with 280 main jets with everything else stock. We ran Polaris M-1 weights in the primary with everything else in both clutches stock. We also recommended a 20 tooth top gear. These pipes run at 9000 to 9200 RPM, it is very important to run 9000 minimum as the engine has real bad harmonic vibration from 8400 to 8700 RPM. Hope this helps."
By the way, I have a bunch of odds and ends 650 stuff left over when I didn't follow through on the swap. I have 4-5 sets of cases (two sets milled for higher compression), crankshaft cores and partial crank pieces, some stators and coils, a couple heads and a bunch of front and rear coolant tubes. If you need something, let me know, I might have something! Thanks! Mike
"It’s unlikely that the pipes are actually 600 pipes although they may be. We did build 600 pipes but built many more 650 pipes which will work better then the actual 600 pipes. The only way to know they are our pipes is that they would have our stamping on them and if the exhaust header flange hasn’t been changed we did put markings on them as well but they get hard to see after time as they were put on with an electric scribe. As for tuning, I don’ have any info on the 600’s but for the 650’s we took the foam out of the air box and started with 280 main jets with everything else stock. We ran Polaris M-1 weights in the primary with everything else in both clutches stock. We also recommended a 20 tooth top gear. These pipes run at 9000 to 9200 RPM, it is very important to run 9000 minimum as the engine has real bad harmonic vibration from 8400 to 8700 RPM. Hope this helps."
By the way, I have a bunch of odds and ends 650 stuff left over when I didn't follow through on the swap. I have 4-5 sets of cases (two sets milled for higher compression), crankshaft cores and partial crank pieces, some stators and coils, a couple heads and a bunch of front and rear coolant tubes. If you need something, let me know, I might have something! Thanks! Mike
X
xc6rider
Well-known member
Thanks. I haven't even seen the sled yet, so I have no idea where I'll need to start to get it ripping. From the sounds of it, I just need to verify the crank condition/engine itself, then probably just get me a decent starting point with jetting/clutching.
Is Decker still in the aftermarket, and anyway to get ahold of them?
Is Decker still in the aftermarket, and anyway to get ahold of them?
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