Help with 1985 3607

D

dougnash

Member
Joined
Apr 5, 2011
RO Number
32517
Messages
42
Hi my friend just acquired this boat at the beginning of the season.

He had a 23 ft walk-around previously and has been an "outboard" guy all his life.

I have been helping him learn all the systems as well as help him understand how to dock w/ twin screws

I have a few questions for members with this type of boat (I own diesel)

It has mercruiser 454/330hp engines, what should max rpm be and optimum cruising rpm's ?

I found 3550-3600 rpm's is a nice cruise rb2@gr5t 18mph on GPS and provides a nice "V" wake

Also what should water temp of motors be? one gauge says 125deg and other is about 160deg

The higher reading engine just had water pump switched for new and still same temp

I guess next try changing the temp sending units for gauges?

He wants to add a dinghy, any suggestions on what mounting system works best to rig off the swim platform for inflatable with small motor?

Thank you in advance for any help!
 
Closed cooling or seawater cooled? Is the boat in fresh water or salt?

Either way his introduction to boating will be expensive because the entire cooling system should be gone through especially if it is in salt water.. This is normal maintenance every few years but he probably has no info on if it was ever done.
 
As far as max rpm...the engine should turn up to 4600 at WOT. Best cruising rpm...to stay out of the 4 barrels...is approximately 3400 to 3500....speed will vary. The temps on raw water cooled engines of that vintage should be about 140 degrees. It sounds like one may have a 160 degree stat in it, which would let the engine run warmer. probably the least expensive and easiest system for dingy is Weaver Davits.
 
Agree with Kenny - he's our resident Carver expert.

I have had a freshwater '82 3607 with same 454 motors, rated at 350HP since 2003. Both Engines have been completely refurbished less than 100 hours ago. STBD engine runs at 160, while PORT engine runs 15 degrees cooler, both with identical new thermostats. i suspected the difference is I replaced the STBD engine raw water cooling pump with a crank mounted/driven unit (stock unit is belt driven). I doubt that the CCW vs CW rotation of these engines has that much effect, but who knows... It would be interesting to know if your engines align (STBD - Port) as mine do on temps as I have also wondered why...

I typically cruise between 3200-3500.... Planes nicely there, and although I can claim she's never economical, it is much kinder to my wallet.
Regs,
Don
 
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