sparkie124

Hello guys, Im having some issues with either my prop or the 496ho going into 90% mode. I am running a velocity 290sc 496HO/B1 and a bravo one 4 blade 28p. the prop was worked by BBLADES last fall and I had to store the boat before I could test it. I have now had it out 3 times and was thinking the lab job was just off a bit. I called and talked to brad at bblades today and now im thinking maybe im in gardian mode at dont know it. I can only get 4600 RPMs and about 55-57 MPH at even trim and tab. If I trim to the moon it will go 60, but thats about it. Im not looking to trash the drive so we just enjoyed low speed cruising with regular trim. I thought i had heard a beeping sound but couldnt pin it down. Nothing on the dash was out of line so i didnt even think about having an issue with the gardian system. The boat is loud and windy and i'm half def from hot rodding so cant even say for sure i heard any thing. There is so much info on the gardion subject out here i am now confused about it all together. I am not asking what the problem is here, I will have the computer read out done local. I am curious as to how the motor goes into the 90% mode. My math = 90% of 5150 rpms is 4600rpms. so is this why i might be only hitting 4600 or does the 90% have nothing to do with RPM. Am i thinking too much into this?? Please give me some imput here.

blownhammer2000

iTrader: (1)

i would throw your prop on from last year and see if you are turning the same rpm's now that you were last year, sure way to tell if its the prop or not

i'm assuming this is a single, 28p bravo seems alittle steep for a 290 velocity, i'm not sure i could turn that in my 25 with the HO

Raylar

If a scan tool or your smartcraft monitor is showing 90% power above certain rpms then you have an issue that is not prop related unless you are hitting the soft rev-limiter, which on your 496HO should be at 5150rpms. Check on the instrument giving the 90% level and see what rpms it is first showing up at. If its below lets say 5100 -5150 rpms then the prop is not the real base problem.
Usually 90% power levels come from low water pressure at higher rpms, exhaust manifold coolant temperatures to high, engine coolant temperatures at the top of the range limits, low oil pressures at high rpms, low drive lube bottle levels, etc, etc. Major fault codes will generally start a greater reduction in power level percentages and get worse down to a 10% or so level (limp mode) until they get so far out of range they kill the engine entirely. Read the fault code history out of the ECM and see what quantity and type of faults are occuring.

Best Regards,
Ray @ Raylar

sparkie124

The boat has the small smart craft display but im not sure how to scroll threw it. Am inderstanding that it will display 90% when in that mode. here is xactly what I did.....Ran it up to full throttle with tabs up and trim @ my level sticker on the indicator, Looked down and was at 45-4600 rpm. running 55-57 mph on gps. No beeps at this time (i think). I started triming up and the boat picked up speed and little rpm. At the #8 position on the drive with a funky roost (probably not good that high) but the boat kept picking up speed. I think that is when I heard the beep but again it was loud with the wind and motor. Would that have just been becauze I was over trimed? Will it only go into 90% mode at a certain rpm? I had a new cool fuel system installed when i got the boat and serviced the drive ect...Was told it had no codes and was ready for use. Also this is the prop from last year..I just got the boat at the end of last season, the prop was beat up so i sent it in for refurbish. It came from velocity with this prop(labbed). I am now looking for a local mechanic to do the ecm read. Thanks for the help. Ray I spoke with you about your kits the other day and was thinking I was over proped, I will get this sorted out first.