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gero1
07-07-2008, 08:32 PM
put headers on this spring and seemed to have gained 200 rpm at idel...= 7.5 mph in the marina. not good! also the timing was set 12 in the computer, any one know what it should be set at from the factory?

farmer tx
07-07-2008, 10:56 PM
What engine package??:bonk:

BigGrizzly
07-08-2008, 11:08 AM
Leave it alone, you have the 415 HP engine which runs a bit rich anyway. Enjoy the boat an d don't run out of gas for the engine:wink:

justleft
07-08-2008, 05:42 PM
Oh I hate it when I have to bump it in and out of gear to pull into the marina or
are about to run over the boat in front. :doh: That's when seperate shift and
throttle levers are real nice.

You learn some real finesse when you need to bump it into gear to steer and then have to
yank it back out to control speed !!! :) Becomes an art.

gero1
07-08-2008, 06:32 PM
the boat has idled at 600 for 4 yrs all i did was put headers on it this spring and now it's at 800rpm...vacume leak? from what i have read it's a stock 502 with 415hp on the prop shaft in a 1995 black hawk. the timeing was set at 12d and i was told it's supposed to be at 4-5d. it was idleing at 800 before the timing was put back to 4-5d in the computer

BUIZILLA
07-08-2008, 06:40 PM
leave it at 12...

MOP
07-08-2008, 07:17 PM
You may be able to slow it down a bit by putting your tabs full down, added benefit it will track dead straight no more wandering. Mine was a little quick when I had the BH on it the tabs helped.

Phil

Tidbart
07-08-2008, 07:25 PM
Am I missing something here? Put the timing wherever you want it to be, and then adjust the idle down????

B

gero1
07-09-2008, 08:05 PM
the timing in the computer was set at 12, is this what it was set at from the factory? or did someone go in and change it? idle is also done by the computer i think. tabs down slow it down from 7.7 to 7.5

MOP
07-09-2008, 08:38 PM
Base timing is not real important, top timing is. I am not sure what the 502 calls for, I run my SB at 34. I have a buddy with 10.5 compression and aluminum heads running 38, you can not go that high with iron heads in a boat. Put a light on it and see what the timing is, should stop climbing at about 3,000.

Phil

roadtrip se
07-09-2008, 10:20 PM
Std 502 Specs call for 650 to 700 RPM idle IN forward.. AIR, 'hawk's are the same.. As far as checking timing, it needs to be done with the ECM in the service mode... If you don't do that, don't mess with the timing..
Check the IAC for proper operation.. Your timing may be advancing a bit because of the high idle... However, if the IAC has lost it's feeble little mind, it shoud reset after a couple restarts.. There is a possibility the TPS is sticking, but it is a remote one..
Of course, it could just be a sticky throttle cable :nilly: :nilly:

I could have sworn that the 502 for the BH was set up from the factory to idle a little higher than stock to compensate for moving so much prop.

Of course, all of my literature is back in Michigan and I am in Kentucky, so I'll have to check when I get back.

Not sure it would have made any difference considering the boat has already been taken back to the shop, but my vote is for don't mess with the ECM.

mrfixxall
07-09-2008, 10:35 PM
Just turn the idle down,,as long as as thetps reads under 1 volt it will be fine and wont mess with the ecm controls..I adjust them all the time! somtimes the iac will stick,heres how you test it ... rev the engine to 3k in the water, unplug the 4 wire iac motor on the throttle body. pull the shifter back to idle,if it dies its working..also you can check the tps(throttle position sensor) with a dvom at the 3 wire plug one wire is ground then 5v reverance from the pcm then one that goes back to the pcm which adjuste the fuel rate..it should read under 1 v if its over then either the throttle body is dirty from oil and carbon build up and is holding the throttle blade open just enough to make the boat idle higher or the idle screw is set to high or the tps is out of range..

good luck.

gcarter
07-10-2008, 05:58 AM
I could have sworn that the 502 for the BH was set up from the factory to idle a little higher than stock to compensate for moving so much prop.
Of course, all of my literature is back in Michigan and I am in Kentucky, so I'll have to check when I get back.
Not sure it would have made any difference considering the boat has already been taken back to the shop, but my vote is for don't mess with the ECM.
I once saw a BH w/an Alpha shift interupter to compensate for the props. That's a simple and inexpensive fix.

RedDog
07-10-2008, 06:30 AM
I could have sworn that the 502 for the BH was set up from the factory to idle a little higher than stock to compensate for moving so much prop...

I had heard that the 502 was used vs the 454 because of the additional prop. The BH 502 is the same as the non-BH 502s

MOP
07-10-2008, 09:33 AM
I once saw a BH w/an Alpha shift interupter to compensate for the props. That's a simple and inexpensive fix.

George I don't see how that could have worked, you need the full engine bump to get those wheels spinning. I was running 26's on the BH a lot less wheel then a stock BH setup, I idled it a 800 to keep it from dying at the docks.

Phil

glashole
07-22-2008, 10:51 AM
is that boat of yours running properly yet or what :nilly:

if you have to deal with the extra rpms,

just remember the hand signals that we talked about when dealing with the people on the dock who seem to think you should be slowing down inside the marina :)

txtaz
07-22-2008, 03:46 PM
I'd say add a couple hundred pounds of rubber duckies in the ****pit. That should slow you down in the marina and getting out of the boat.

Ohhh, I still have a copy of the Bert and Ernie CD (RoadTrips party mix) if you want one.

Da Taz<---Wondering when Todd is going to get creative.:smash:

MOP
07-22-2008, 04:23 PM
A little giggle from a Smack Master!

gero1
07-23-2008, 07:57 PM
will get the boat back tomorrow and try to take it out this wkend, lots of little stuff wrong......will see

gero1
07-28-2008, 06:49 PM
it's done, the hi idle was caused by some jack a#@ who put the thermostate in wrong(me) the motor stayed in cold, rich mode because it would never warm up

BigGrizzly
07-29-2008, 07:56 AM
Robbert it just doesn't matter as long as you got it fixed. I made a big mistake at Lake George which ultimately saved me from a fried wire harness(possible fire) and from a burned up new alternator. I was just lucky. Some times mistakes are a good thing.