Thread: Opinions needed. Ported 1300.
07-31-2010, 08:20 PM #1
Slow 91's ported 1300 progress thread.
Hey guys, finally got out to the water this weekend with my Gp1200R/1300 Tj Ported Top End. Here are my current mods. Motor has roughly 4 hours on it:
TJ ported 1300 Top End
Riva heads, Cut by TJ
Riva Gas Valves
135 main, 120 pilot Jets
Advent Yam 84 curve
Non Jims plate angled
Trim tabs shimmed
Nujet 6.5 Prop. i think its a 12/18.5
Broke the motor in yesterdar for about 2 hours. Compression is 150.151 152. I started to do some plug chops, basically i set my highs 2.5 turns out. There was alot of boats today and the wayer was very rough in some areas so i couldnt get to do alot of tuning. On calm flat water i was able to pull 72.6 mph and it was at 7280 RPM's.
I know i still have much more tuning to do but i think im down on speed. Would pitching my prop some more ( i was told 14/23) gain me more MPH?
Last edited by Slow 91; 09-06-2010 at 07:08 PM.
07-31-2010, 08:26 PM #2
- Join Date
- Oct 2006
a dynafly 14/23 on an HO pump is about right for that setup, currently your spinning a little high, aim for 7200.
it should turn it at around 7200 @75mph+....however you need an 05+ spec pump setup but the increase in hookup is well worth it imho.
07-31-2010, 08:58 PM #3
- Join Date
- Jan 2006
- Texas City, Texas
New Jet impeller and 2.5 turnout on the jets are working against you right now. As you dial in the carbs by turning in your screws, your RPMs should significantly increase. In time you should see that it is not the right impeller pitch.
Be patient, go slow, and the speed will come as you tune.
08-01-2010, 11:34 AM #4
- Join Date
- Apr 2006
- South MS
The right pump/prop is everything. Just to give you an idea. My single pipe will go 77mph+ on a '05 pump and 14/23.5 dynafly prop at 7030rpm. Other day I put a stock '01 pump and a stock 1300 prop in it and could barely hit
70mph at 7250rpm. Thats 7mph difference !!! Who would have thought....but thats exactly what it did.
If you can get a 14/23 and '05 pump in your ski and spin it 7200rpm then depending on hull setup you should go 80mph+
08-02-2010, 11:06 AM #5
i hope that a prop pitch will wake this ski up.
08-02-2010, 11:11 AM #6
Talk to Inkaddict on ECP, Chris. He is very knowledgeable of this setup and hes local. His ski was running a consistent 77/78mph from what I remember.
08-02-2010, 12:06 PM #7
yea, i will. I have shot out some pm's to people who have had or has a setup like mine. Im going to tune the carbs a little more and see how that does. Once i do that i will get a prop/pump and see what happends. The ski ran ALOT better by the end of the day when i played with the highs and steve tackled the lows. It was soooooo rich comming off idle it barley stayed running.
08-02-2010, 01:32 PM #8
I have a HO pump with 30" DS and brand new bearings and seals. $450 and Ill throw in a DF pitched to your specs for an extra $225 Ill even throw in the tunnel relief valves and weldable bungs.
08-02-2010, 01:51 PM #9
08-11-2010, 08:10 PM #10
Ok, just picked up the HO Pump, and DF 15/23 prop. Im going to throw that on the ski and take it out sat, finish tuning the carbs and see if i can pull out some high 70's.
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