Gizmo

James, I understand that you changed the cams in your engines. What cams did you install and did you change lifters.
I'm looking at changing mine......

Griff

Use the standard wire harness that US1 posted a link for.



Keep in mind this will only work if you have a TB IV ignition. Just because its carbed doesn't mean it has a TB IV. If its a TB V then you have to send in the ecm to have it raised.

According to www.mercruiserparts.com the last year of production for carbed HP500's was 1998. They could still be in a 99 boat. Depending on serial # they could have TB IV's or V's.

Also, I see no reason to remove the rev limiter on a stock engine. It is there for a reason and you should prop the boat accordingly. A modified engine may need to spin higher rpms to make its power.

excursion

Yes, that is what I am doing. My motors are not in the stock form anymore, my new peak RPM power is at 5500-5600 rpm, could not get there. I was also told that the TB V ignition is preset and CANNOT change the setting. I called Arizona Speed & Mercury Racing dept, they were NO help at all.

Gizmo, we put in a 112 lobe center Crane Cam. I also bored them out 30 over and pumped up the compression to 9.75 / 1 and did change the lifters. Had the heads ported and intake port matched. AED 850HO cfm carbs also.Everything balanced , Few more little things done. Sounds great!!!!!

JaayTeee

Check this thread out:

http://www.offshoreonly.com/forums/s...ad.php?t=98792

Now........ get that thing back in the water.

I want to know how those shorties end up working .

Strip Poker 388

No help at all ? I have heard that before


What it the factory rev limiter set at????

Rob

Mudball

My TB-V on the HP500 is set to 5,350. At least mine is...
Kent

excursion

Hey Rob, I called twice too the Mecury Racing department trying too get someone to help me, and both times asked what my rev-limiter was set at and got two different answers
it is either 5250rpm or 5300rpm, but as someone else said theres is at 5350rpm ??????????

I will see today how it works, heading up to a local lake for some prop test.

5 blade 30"
4 blade 31"
4 blade 32"
4 blade 33"

Post results tonight.

Gizmo

I too, was under the impression that the rev limiters were set at 5250. There have been several replies that suggest to bypass the limiter. I don't get a warm fuzzy feeling with that idea. So, I did some investigating an found that MSD has a rev limiter ($129.9 list ) that has modules for several RPM ranges. The module kits are $34.99 ea. and have five modules in each kit. example: 5000, 5200, 5400, 5600 and 5800 RPMs. That sounds like cheap insurance, to me.

excursion

I need to get a pair of them, got a little high today at one point when the boat left the water and spun up to 6000rpm,
Want that as a back up.

Were did you find them at??

Griff

If I was going to buy a rev limiter/modules for $150, I would just get a Crane ignition box for It will wire directly into the merc distributor, has most of the merc advance curves built in, and has a built in adjustable rev limiter. I think they are around $300.