krypto 1 in CT

hmm i took mine out to this weekend with 30+ mph cross winds out on the water i couldnt go for it.well actually i did and it started dancing REAL bad chine walking and i backed out.but i also noticed that if i hammer down on it i feels like the motor flatens out around 5000rpms.then if pull back to about 3/4 throttle it seems to pick back up and pull real hard.maybe the blower belt is slipping and when i back off a little it catches up and grabs? anybody else have this problem with a procharger? i have the nickerson carb on and did a few plug checks and they look good so far(DIDNT GET A FULL THROTTLE PLUG CHOP YET THOUGH)and all i needed to do was adjust the idle screw about 1/8 turn.

cooltoys61

I had that rev limit feel one time and had the timing way high,,blew a hole in the piston. Also the dieseling doen't sound good. Can you get a timing light with built in advance?Are you sure you are rich at WOT and not just after coming in? I'm probably less knowledgable than you, but that's my 02.

HPJunkie

Hardcore how big is your boat, what brand? Just curious as Im running a similar setup. Greg

jspeeddemon

My experience with carburated procharger is that it tends to lean out on top, keep in mind that if plugs are rich in midrange, a short blast at WOT is not going to clean them up, although you may be lean on top end. Are you using the power valves, there was a good thread regarding this subject some time back, regarding the power valves and the correct opening under boost. Basically it reads the difference in pressures. You may want to investigate this issue.

krypto 1 in CT

yeah hardcore you need a timming lite with a advane knob so you can set it at 30 or whatever you want and rev it up and dial in toal advance.no need to take the balancer off and degree it a good timming lite will do the job.

Hardcore

Thanks for the reply guys. I don't have a "dial-back" timing light so I have to rev it up in neutral till the timing stops (like 3500 RPMs or so) and check the max advance on the balancer. I don't really like the dial-back lights because from my (albeit limited) experience and from what I've read, no two give the same reading (usually like a few degrees off).
I don't think it has a hole in the piston though because I would probably have noticed that by now (I hope!).
I think I'm gonna go way rich and try it again. It might be high speed lean out.
I idled down and shut it down quick (but didn't kill it at WOT) and checked the plugs in the water. I don't think just idling down like that for a few seconds would change the look of the plugs that much, though. The plugs have a light brown/tan discolouration on the center insulator/electrode and black soot on the threaded part. I'm currently running 12 jet sizes bigger than the carb came with and I have two power valves (6.5 HG) so I thought that would be enough fuel. But, better safe than sorry!
I'll jet it up to like #99's and work my way down.
As for marking the balancer all I'll do is measure the circumference of the balancer (with like a cloth tape), (or you can calculate it from the diameter (pi x radius (1/2 dia.) squared - I think) divide it by 360 (as in 360 degrees) and then multiply that figure by 30 to get the measurement from 0 (TDC) to 30 deg. advance.
BTW: HP Junkie, I have a 1995 American Offshore 2600. I'm running a stock B-1 L/U with nosecone.

Hardcore

I jetted the carb up this weekend to #94's all round and now the motor is running way rich. I checked the timing and it's definitely at 28deg. BTC. I also reinstalled the fuel inlets that came with the carb since they have bigger orfices than the .110" inlets that came in the Holley Trick Kit. This is something to look out for because when you have positive displacement of air through the carb ("blow through") the carb will need to flow fuel like it was a Dominator and the bowls can only fill as fast as the inlets will let them. The larger the mains (and the higher the air pressure in the bowls) the quicker the bowls will empty out so you need to keep up the flow. This is quite possibly why some P/Charger (and other blower) setups lean out at high RPM. I'm still not certain that the inlets I have in the carb are big enough so I'm going to order some .150" steel or Titanium ones to make sure.
I also installed the anti-pullover ("butterfly") squirters to prevent fuel enrichment through the accel. circuit.
I ran the boat with two other people and a bunch of gear on board and it ran easily up to 96MPH on the GPS but then it gets to 5600 RPM and starts to lay down - like it's flooding or running way lean. I think if it was lean I would have hurt the motor by now and the plugs are telling me that I'm drowning them (the whole end is black and wet). I have never seen over 5600 RPM and I'm even starting to wonder whether my 6000RPM chip is off by 400 rpm because the thing pulls like a freight train up to that point. (I mean 60 to 95 MPH feels like my old Drag-Motor Mirage did with a 24" Yamaha prop!)
Also, I am getting over 15lbs of fuel pressure at full boost (5lbs) so I'm wondering, is it flooding up there because the seats can't handle that kind of pressure (effectively 10 lbs of equivalent atmospheric pressure)?. I have the Aeromotive regulator referenced off of the carb box and have it set at 7.5 lbs static (about 5.5 to 6 lbs with idle vacuum). I guess I'll go back down to the #90 jets and gradually drop the pressure. I'm also ordering a labbed 32 Bravo 1 prop because I'm convinced the one I have is not the prop for my application. Stay tuned for next week's episode...

krypto 1 in CT

sounds like your getting pretty close.mine is laying down at 5000 then if i back down to 3/4 throttle it starts pulling hard and you having to slowly inch the throttle up.full msd 30 total advance 5600 chip with a new nickerson blow through procharger set up carb (hp 500).the plugs look perfect doing a midrange plug chop a little rich after idling in the harbor and flushing it.i havnt been able to just give it a full run and plug chop as its been to windy so im planning on it this week.i also have the aeromotive pump/reg boosted of the box set as low as possible at around still 7+psi at idle and up around 13 under boost.im think my belt might be slipping up top end causing it to lay down around 5000 after doing a search on some old posts. so i put about 4 to 5 turns on the tensioner and its ready for another try also.

Turbojack

I think you need to put 2 more degrees of timing in it for total of 30.

On fuel pressure, if the regulator is refrencing the carb box the pressure is going to be the lowest when the engine is off & go up from there. I thought that the Aeromotive regulator was a 1 for 1, that means as pressure goes up the fuel pressure goes up equal amount. As motor off 5 psi, motor running pressure in box say at 3 psi, then fuel pressure is 8psi. In effect the carb is only seeing 5 psi, since pressure around it is at 3 psi. If your pressure is going down when the engine is running you may have a fuel pump or supply problem. That could explain the laydown @ 5600rpm

Nordicflame

iTrader: (4)

I thought the carb setup used a 1:1 regulator and the EFIs the 3:1 to up the injector capacity. Is it possible you have an EFI regulator?