Ok heres the deal, saw a neat contraption down the road and had to have it. Its a 14ft tin boat with some flavor of kawi jet pump and a sled engine driving the pump.
Figured i would buy it just for a laugh, the guy that owned it had never fired it up let alone run it so i hadnt much clue what i was actually getting. apparently the guy that built this was an old timer, steam engine mechanic!
It does look pretty rigged up but it is actually a solid setup.
Anyways, the thing does run well but it is definately lacking. It tops out at about 'canoe' speed with 2 of us in there! Good enough to go down the lake a little bit to have a beer but not much fun!
Im new to the whole PWC jet pump scene and i dont know if its the pump thats too small of if its driving the pump too fast or too slow. With the belt drive setup thats on it now, it should be theoretically be spinning the pump at 15-16,000rpm since the belt drive is at a 2:1 ratio of the driven pulley of the engine(lil 294cc pos)
Heres what i have for pics at the moment. Let me know if their is something specific you would need to see...
Some guys on another forum are pretty sure its a 300/440 pump. I will probably be pulling it apart this week sometime to check the condition of the impeller/housing.
Is their anything i can measure or take pictures of that can positively identify this as a 300/440 pump?
I want to make sure i know 100% what it is as i want to order up a different impeller, something like a 15/18* or straight 18* to hopefully move some more water. Granted thats not whats already in there...
Looking for a HI# all along and it was right infront of me...
According to the kawi website this contraption used to be an 87 JS300. Though i see the Js300 and the 440 both have the same part numbers for impellers and pump cases, are they not identicle pumps or are their a few small differences?
The clutch system will slow you down because that impeller was meant to spin at 7000 rpms and the clutch slows that down to maybe 4000 rpms. Might need to get a super low pitch impeller, like 9 degree.
the cvt clutches at full shift give me a 1:1 ratio, but the belt drive down to the pump is whats screwed up!
When i first got the boat the belt drive was set up at around 2:1 which would give me 16000rpms(ish) at the pump at full shift on the cvt clutches. But it never had the power to fully shift the cvt so i only had 8000rpm or so at the pump. I went and got another pulley for the belt drive and its now very close to 1:1, slightly higher, but now the cvt clutches can fully shift so i still end up with about 8000rpm at the pump but its alot easier on the belts.
Most of the issue with this setup is the whole belt drive contraption. It starts off with a junker 294cc engine that had probably 20hp back in its day, then it looses 5hp in the cvt clutches, then another couple hp on the belt drive. I would like to just find a pwc engine to put into it and mount it up directly to the pump, but i think thats going to put too much weight too far forward in the boat
A forum community dedicated to PWC owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, maintenance, for all SeaDoos, Waverunners, and Jet Skis.
