07-10-2009, 03:20 PM #1
Having a few issues on Stg3+ - help?
I am having a few issues this year, looking for a little input.
My setup from last year is in my signature … Over the winter I pulled the head, installed Ferrea valves, decked the head, new head gasket, etc. I also retarded the cam a bit, its close to fully retarded based on where the bolts are in the slots. I also upgraded the X charger by adding the ET 137 wheel/spacer; Jerry rebuilt the charger. Oh, and put on an R&D grate instead of my Riva, just to try it out. The rest of my setup is the same as last year – Riva ECU & springs, 50 lb injectors, GH box, etc. Last year with the stock X charger I ran 80 – 81.5 mph depending on the weather and the nozzle I was running at the time, rpms 8400 – 8600 depending on temps and setup.
First time out I had put in the 80mm nozzle and expected to be around 8400 + rpms with that since I ran 8400 rpms with the 81.5 nozzle with a stock X charger … instead it only ran 8000 rpms. I pulled off the Riva rear air filter and put in screen instead … it then ran 8150 rpms. I noticed oil in the intake and IC, pulled the charger, checked slip and changed spark plugs since it seemed to be running rich. I then swapped to stock 83mm nozzle, and it ran 8400 rpms, but it should have been all over the limiter with that nozzle. I also checked for boost leaks, there were none.
The problems I am having this year: 1. Oil in the SC, looking at possible solutions for that. 2. Low rpms and speed, only ran 78 mph at 8400 rpm with stock 83 mm nozzle, but I did add a modded R&D grate, need to swap back to my Riva grate I think. 3. Runs rough at no wake speed, rpms at idle fluctuate more than before, and it seems really rich/runs rough at 2200 – 2600 rpms. 4. Filled my catch can after one good ride (burned about ¾ tank of gas). 5. Idle is definitely rougher than last year, varies from 1700 - 1900, no big deal but might also be an indicator of an issue.
Checked slip, still at 110 in lbs, no boost leaks, starts and runs good other than it seems to be really rich … this puzzles me since the boost should be up 2 lbs over my setup last year, which always ran great at any rpm and put very little gas/oil in the catch can.
So I am looking for some input … wondering why with a bigger SC wheel I am running way richer this year? (No RRFPR on my ski) Would the oil from the SC cause it to run really rough and rich at 2200 – 2600 rpms? I changed spark plugs, zero change at all. Would retarding the cam cause it to run richer? Based on what I ran last year, I had hoped to be up about 200 rpms, but instead I seem to have LOST about 300 rpms and am running rich. Very strange … what effects are normally seen when you retard a stock cam?
Last edited by Vern; 07-10-2009 at 03:24 PM. Reason: fixed
07-10-2009, 03:31 PM #2
Check this thread Vern:
seriously.....i would check the bell of the manifold, i had issues with this last year.
remember the bigger wheels need a lot of torque on the slip. i have been running around 140-150in/lbs on mine.
i would go back to the riva grate and see if the r's come back.
also be sure to check the pump shoe as it seems a lot of guys have seen them flex and casue drag.
07-10-2009, 03:34 PM #3
you could also do a leakdown and compression test to see if the valves are sealing up.
07-10-2009, 03:38 PM #4
Yup, I checked that thread already ...
Greg do you mean the bell on the exhaust manifold? I have a new manifold, perfect bell, and had it Jet-Hot coated too, so no exhaust leak.
I will swap back to the Riva grate ... that is one variable I can eliminate then. I forgot to add that I also reinforced the pump shoe, and added Erik's protector to it too. It is possible the R&D grate is too aggressive and overfeeding the pump and causing drag, but I still can't figure out the ski being so rich down low, running rough at no wake speed and filling the catch can so quickly. I expected it to be leaner rather than richer ... I have McMaster washers so I can bump the slip up to 150 in lbs too.
07-10-2009, 03:51 PM #5
What is temperature and the humidity? it plays a big roll, you could loose RPM istead of gain RPM.
I have the same setup as you except 42# injectors and RR ECU with FPR, on winter I ran 81.7 PMH with 81MM ring but I'm running 82MM at 78.8 on summer. It did drop about almost 200RPM.
07-10-2009, 04:13 PM #6
The air temp was close to 80, water temp about 72, and was humid, so that certainly could be part of it too, but the weather is not terribly different from the previous summer when I ran quite good speeds and rpms.
I should do a comp check just to be sure too. I am just puzzled by the combination of issues with it being rich and down on rpms ... not what I expected.
07-10-2009, 04:29 PM #7
07-10-2009, 04:36 PM #8
It seems very rich down low mainly ... the plugs I took out looked great, not black or rich looking ... I have not hooked my boost gauge up to it yet, the gauge was not reading right last year.
07-10-2009, 04:39 PM #9
Vern i have seem some units that have had "gassed up" oil and run rich.
Is your oil overfull or seem to smell gassy or be a little runny?
07-10-2009, 04:46 PM #10
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