- Location
- Fortwalton Beach Fl.
What were the claims of the gen 1 and 2 pipes?
650/X-2 advertized hp claims coffman 650sx pipes
- Thread starter anthonystempak
- Start date
- Location
- the jetski grave yard
since i bought out coffmans remaining jetski inventory, they gave me a "coffman bible" must be the new testament, cause there aint no book of genisis or info on the gen 1 pipe. gen 2 rocket series coffman classic (cast pipe) creates 62 peak hp @ 6500rpm. bone stock is 52.1 @ 6000. 10 hp, not bad. pam coffman is a sweetheart and would probably answer any questions she could, if you called the shop. gary coffman, on the other hand, nice guy but hates the dick heads in the jetski world and would rather not discuss it. i can relate.
- Location
- CT
Ya I was going to say I recall gains of 10hp on 650 20hp on 750s and 30hp on 1100s
- Location
- Fortwalton Beach Fl.
I don't know factory claims 36% increase unless lm doing something wrong thats 70hp +8hp over coffman
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The gen 2 650 pipes used a 5" center coupler. They were clearly made for the typically over propped 650s of the day. They are good pipes. A stock 650 cylinder with 178 degree exhaust will pull to 6600 RPM with good response and top 43mph. I installed a full length one on my 750 X2. At 190 degrees of exhaust, gps recorded 51 at 7100 rpm with good response.
Myself
manic mechanic
- Location
- Twin Lakes AR
Hell, my stock cylinder, STOCK piped 650sx with stock 28mm carb will top 43mph! Surely a Coffman can do better than that.
Myself
manic mechanic
- Location
- Twin Lakes AR
I have 'tuned' mine. I added 3" to the chamber at the coupler. Dried out the exhaust. Gasket matched the manifold to headpipe. Drilled a few holes through the baffle in the waterbox. Tweaked my old Mako 16 impeller. "Power" tuned the carb. And did my "fast burn" mod to the stock head.
WFO Speedracer
A lifetime ban is like a lifetime warranty !
- Location
- Alabama
The engine in my 300SX is the one that I had in my fixie 650SX , its ported, bored 2mm O/S , the cases were ported, I also ported the exhaust manifold and opened it up to match the Coffman pipe and shaved the stock head , it runs stock ignition , a 44 carb and two inline resonators , no waterbox, that thing will absolutely eat a 750's lunch.