Thread: What kind of prop to start with?
12-30-2006, 04:02 AM #1
What kind of prop to start with?
I will be in the process of building a triple piped 1390 Lowell setup this Spring. Im currently running this 1390 single with a Dynafly 15/25 in the new HO pump.
Just curious as what prop is suggested with this setup with stock carbs and Advent CDI. I just need a good starting point.
12-30-2006, 08:36 AM #2
I would keep that same prop and see what the RPMs come in at on your first runs. You might even have to depitch a hair because keep in mind that tripples run higher rpms than the norm for singles. You will at least need to be able to spin 7500-7600 rpms to start with.
12-30-2006, 09:50 AM #3
I am using a 14/22 spinning 8050 rpms.
A 14/23 does 7860.
12-30-2006, 10:46 AM #4
12-30-2006, 12:11 PM #5
Yes its a 1390.
So I would be better off starting with the prop I have then depitching to tune the rpms. I would think the pipes make the best power at around 7800 rpms or above, anyone disagree?
12-30-2006, 12:13 PM #6
12-30-2006, 12:19 PM #7
12-30-2006, 02:12 PM #8
12-30-2006, 02:47 PM #9
I might not even try this until next summer but the pipes came in today and Im getting excited about them. I honestly dispise the stock pipe and stinger. I understand Triple pipes are more maintanence but it looks like carb tuning will be much easier with the pipes. Maybe Im wrong but from pics the carbs look much easier to get at than with the stock pipe. And that stock pipe weighs to much, what a handful.
Im not new to tuning triple pipes just new to tuning them on Yamahas.
I appreciate your help and will need more for sure. Thanks
12-30-2006, 03:31 PM #10
The carbs on a tripple piper are cake however extra attention to details such as,
Not using oem pistons
Inspecting the top end every 30 hours or so.
Making sure the couplers are NEW and the clamps are tight
Making sure the stinger pipes are touching the collector, If not you will blow a hole through the coupler in a short period of time.
Making sure the rope inside of the manifolds is new
Using the riva heavy duty springs on the pipe to manifold connections
Making sure you grind the front motor mount down enough so the pipe does not rub through.
Making sure your water routing is neat and correct and using hot water off the heads going into the pipes and not cold water from the pump.
Attention to every last detail!
As Mark would say, "The GPR platform demands perfection, if not it will exact its tole in dollars and labor".
Let me know how things go. Any questions just call, 619-729-4200
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