1986 454 WOT

"Having an issue with the WOT

"Having an issue with the WOT on a 1986 11m Trojan. The boat was purchased five years ago with 450 hours. When the boat was purchased it had the wrong props that would only let the boat max at 3200 RPM (The owners manual stated the max RPM was 4400)Through extensive research into what the correct props were for the boat we replace them with 4 blade 24 x 24 blades. The boat maxed out at 4400 RPM. Several years later the boat will only max out at about 3800 RPM. A couple of notes, one the Distributors have been changed since the original purchase of the boat to electronic, two the engines know have approximately 800 hours ( and run like new). I have checked to make sure the secondaries are open all the way at WOT, which they are. Any suggestions would be appriciated."

"Ayuh,..... I gotta believe th

"Ayuh,..... I gotta believe this is a Dockboat,....?..

What's the Bottom,+ running gear look like,.....
Clean,..??
Alittle Growth,..??.. Alot of Growth,.??"

"Believe it or not, the boat i

"Believe it or not, the boat is used frequently from May to Sept, however where we live on the South Shore of Long Island, there is a lot to do including fishing near by, hence the lower hours. Sorry, I forgot to mention, the running gear was just refinished last season, and the bottom is clean (we just had her hauled for the season and the one year old bottom paint did it's job) Further the reason the props were redone is we his a crab trap last year and mangled one of the 24X24 blades. It was recommended that we switch to 24x25 for better efficiancy and lower planing speeds, this helped as the boat planes at 2850 RPM and cruises at 18 knots @ 3200 RPM, however the boat still max's out at about 3800 RPM. Also when we changed the props this time around, they stated it should have only reduced the max RPM by 100 - 200 RPM, which means the boat still should max out around 4200 RPM"

check the timing make sure it&

check the timing make sure it's dead on . it doesn't take much to lose 400 rpm.

"[b]" Also when we changed

"" Also when we changed the props this time around, they stated it should have only reduced the max RPM by 100 - 200 RPM, which means the boat still should max out around 4200 RPM"

Ayuh,.....
While that Is the theory,.....
Practical experince says it isn't always True,.....

Did you experince the drop in rpms at the time of the Reprop,..??...."

"No, it stayed right at 3800 R

"No, it stayed right at 3800 RPM"

"Maybe I'm Missing somethi

"Maybe I'm Missing something here.......

It was Proped at 3200rpms when you bought it,.....
And you Reproped it to 4400rpms,.....

Then you Reproped it again and are stuck at 3800rpms,...??....
Correct,..??..??..??...

If that's an Ayuh,.......

The Newest Props are just Too BIG........."

"No, the 3800 started before t

"No, the 3800 started before the boat was reproped again, however when the boat was repropped to slightly larger props the max RPM stayed at 3800 RPM. The problem started I believe after the electronic distributors were put in the boat. They were complete distributors, not the kits. Other than the boat only maxing out at 3800 RPM, I have not noticed any other issues such as over heating, pinging, or any other issues that may be related to the timing being off. Also, both engines max at exactly the same RPM (I also changed the tachs to assure that was not the issue). I thought maybe there was some stretching issues with the throttle cables, but like I said the carbs (which were rebuilt shortly after the new distributors) secondarys appeared to be fully open at WOT. Since we cruise at 3100-3200, this is more of just a frustration issue as to why the boat no longer maxes at WOT to 4200-4400"

"I have a 1986 10M FB with the

"I have a 1986 10M FB with the same engines. I have the electronic ignition (optional back then) and when I set the timing I remember having to flip the connector around to disable the spark advance. Then flip it back when done. This is not in the owners manual and I have a separate sheet with the procedure, but it's on the boat. I'll check next time I go down. I only cruise at 18kts, so am wondering why you get the same speeds with the bigger boat. I'm running 18x22 props with 1:1 gears and get 4200RPM. Do you have the express or Fly Bridge?"

"Hey, Ed, I feel you are a vic

"Hey, Ed, I feel you are a victim of "paralysis by excessive analysis". Since WE don't run our cruisers at WOT, and OUR boats both have a nice cruising speed at a reasonable rpm, then why worry about that WOT rpm nonsense?

My 32 Marinette tops out at 3,900 on both 360s, yet it also cruises effortlessly at 2,500 rpms and 20 mph. So I could care less, and so should you! Hell, there's enough stuff on a boat to worry about, right?

That said, you should still check the full advance timing with a computerized timing light at 3,o00 rpms--forget that initial timing crap--so you're sure that's not a problem. (Look in the spec book for the total timing and rpm.) When that's done, run a plug color test after a good long run at cruising speeds (with minimal or no idling after the run). Finally, if you don't have them already (you didn't say) consider adding a FloScan to measure your fuel usage. Very handy gadgets! Mine paid for itself in a year by detecting a dirty flame arrestor that was wasting gas on one side.

Jeff"

"In answer to Ralph's ques

"In answer to Ralph's question these are not factory Electronic Distributors, we added thm a couple of years ago and I do do not believe there is anything to flip on these ones, secondly, we to are running 1:1 ratio with four blade props, and the 18 knots at 3200 is measured off the GPS so i know it is relativly acurate. I don't know how much fuel you normally carry, we try not to run with more than a half tank, unless we are going far. To fast Jeff, thanks for the inf, and your right, i'm just picky when it comes to this. As far as the timing, I spoke with crusader and they told me the timing should be @ 10 degrees. You would not happen to know what the timing should read at full advance? Once again thanks for the advice."