Logo
Click for Crusader parts and manuals!
Results 1 to 18 of 18
  1. #1

    Default Crusaders not achieving rpms

    I know I'm opening up for some flack, but need to ask opinions anyway.....I have an old 32' sportfisher with twin Crusader 454's, RAW WATER COOLED. Ive been around boats for 50+ years so I know the negatives of this situation. As some of my friends on this forum may recall, I have owned this boat for 4 years and really never in all this time have I opened them up to see what she feels like planing. For fuel conservation and fear of breakdown of these old motors, I have happily cruised around at 9 knts at 1500 rpms on autopilot for all of my ownership. I believe one of these blocks was replaced in late 1990's and it is possible the other one is the original block from 1976. They have Holley carbs, newer electronic distributors and they never run hot. Temps always look good. When I personally installed the Delco electronic distributors 4 years ago, I did my best to correctly time using help from this group and others. I was, and I am able to throttle up both engines in the slip in neutral. They always fire almost instantly when I turn the key. There is no knocking. There is no smoke.
    But yesterday, for the very first time, I couldn't resist pushing the throttles up to see what would happen. As I increased up from 1500, there was a faint emission of grayish/whitish smoke or water from the exhausts, but when I got to 2100 on both engines, there was a LOT of smoke (or steam) , not black, but darker gray mixed with white I would say. And the engines seemed to stop responding to higher rpm request. The temps remained steady with no rise in temp. There was a lot of station wagon over the transom, so I brought them back down to 1500. Ran fine as always in every regard at 1500. When I returned to slip, I checked the oils to see if evidence of water. They both looked great. Good level and pure looking.
    So whatcha think? Is this a fuel issue, timing issue? ??? I ran them back up in the slip with no load and up they went,, no weird sounds or smoke.

  2. #2
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    do you have the old 'log' style exhausts? when was the last time the riser/elbows were changed?

    Did the engines every achieve WOT? Have you ever checked them for WOT since changing over to the EST distributors?

    If you have an IR temp gun, scanning the risers and elbows, at elevated RPM, would be of interest...

  3. #3

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by makomark View Post
    do you have the old 'log' style exhausts? when was the last time the riser/elbows were changed?

    Did the engines every achieve WOT? Have you ever checked them for WOT since changing over to the EST distributors?

    If you have an IR temp gun, scanning the risers and elbows, at elevated RPM, would be of interest...
    I will try to upload a photo of engines. No, not log style manifolds. They were all changed by previous owner just before I bought the boat, so 4-5 years. I did not achieve wot under load because I freaked out and backed them down. In hindsight, the boat was digging a hole too. I should have trimmed her down to help a little. I have a ir gun, but in this instance I did not read the risers at increased rpms. Normally at 1500 rpms or lower, the risers and elbows are almost cold to the touch. Not even warm.

  4. #4

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by makomark View Post
    do you have the old 'log' style exhausts? when was the last time the riser/elbows were changed?

    Did the engines every achieve WOT? Have you ever checked them for WOT since changing over to the EST distributors?

    If you have an IR temp gun, scanning the risers and elbows, at elevated RPM, would be of interest...
    As a follow up to this.....I am BEGGING an administrator or someone to post clear instructions on how in the heck to add/upload/attach a photo here. I have been on the forum for a number of years and never have quite understood it. Looking at the instructions in the "how-to" section, it says photos can't be attached in replies??? That photos have to be attached only to original new thread??? Please straighten me out because I am not a complete idiot and every time I try to upload a file, it just blasts off to nowhere. Please enlighten me.

  5. #5
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    So, i would guess you have a center riser style exhaust now...good for weight but not necessarily longevity on the elbows...

    Assuming the elbows are fine, I'd suggest checking the ignition timing and ensuring you have full advance by 3400 RPM...and don't worry about the 'timing jumper'...

    On the pictures, I didn't have any issue with the instructions but it has been a while since I posted an attachment. you are well over the 5 post minimum so that should be mute. from what I remember, its a two step process...you upload the file to a buffer space and once that is done, you can add a link to any of your uploaded files. They have to be one of the 'older' graphic file formats and there is a max size (~ 500KBs) so you can't load a 'new' smart phone photo without a downsampling process.

  6. #6

    Default Re: Crusaders not achieving rpms

    i shall try again on pic

  7. #7
    Join Date
    Dec 2008
    Location
    Bourne, MA, USA
    Posts
    338

    Default Re: Crusaders not achieving rpms

    Click image for larger version. 

Name:	Merc-350-rear.jpg 
Views:	2 
Size:	77.1 KB 
ID:	27016Just a test of adding a picture. I first clicked on reply and then Go advanced, selected Manage Attachments and selected a photo to add Inline with the text.

  8. #8
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    i curious as to what the pic content is and how it factors into the issue at hand...

  9. #9
    Join Date
    Dec 2008
    Location
    Bourne, MA, USA
    Posts
    338

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by makomark View Post
    i curious as to what the pic content is and how it factors into the issue at hand...
    The content of the pic is not relevant to the issue at hand but only "a test" of adding a picture. Something that infintyron could not do.

  10. #10
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    Sorry - somewhat ambiguous in my wording....I was getting at whatever is in Ron's pic - the one he can't post...

  11. #11

    Default Re: Crusaders not achieving rpms

    Ok, I will follow those steps precisely, but I believe I have. Let's see what happens. Hit Reply...go advanced.....check...manage attachments....check....select photo from my computer....check.....select photo...check...then the file name appears, so I hit upload.......it does not appear in my reply and the file has flown the coop. So thanks for trying to help but it appears that for some reason, I can not upload a photo from my computer here. I can on every other forum I belong to. This is the only one that I fail on.

  12. #12

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by erich View Post
    The content of the pic is not relevant to the issue at hand but only "a test" of adding a picture. Something that infintyron could not do.
    I've been trying to attach a pic of he engines so you can see my exhaust set up. Perhaps I am incorrectly representing the type. When you say "logs" I always think of my old OMC engine which actually had manifolds that looked like logs. Mine are not center rise risers. I have end cap elbows/risers on aft end of engines.

  13. #13

    Default Re: Crusaders not achieving rpms

    I am curious why all the replies in this thread have a "red" triangle warning emblem on lower left on my end.

  14. #14
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    The attached PDF file shows the OEM "log" style exhaust manifold....drawing is from the parts manual so won't have much detail.

    the red triangles allow you to notify the ADMIN that a given post is SPAM....
    Attached Files Attached Files

  15. #15

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by makomark View Post
    The attached PDF file shows the OEM "log" style exhaust manifold....drawing is from the parts manual so won't have much detail.

    the red triangles allow you to notify the ADMIN that a given post is SPAM....
    Yep, those are my manifolds. They were new in 2016 and run cold to the touch in the slip.
    As for the spam warning triangles.....all of mine seem to have them. Maybe that's why I can't add photos? And I'm not a spammer

  16. #16
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    8,868

    Default Re: Crusaders not achieving rpms

    all of the new posts have had the triangles for a while now.

    Did you ever check the WOT RPM after all of your parts swaps? Before then?

  17. #17
    Join Date
    Jun 2008
    Location
    Island Heights, NJ,
    Posts
    3,622

    Default Re: Crusaders not achieving rpms

    ....compression check???
    Capt Bob
    1969 23ft ChrisCraft Lancer
    Merc 5.7L 260HP/ Volvo 280

  18. #18

    Default Re: Crusaders not achieving rpms

    Quote Originally Posted by sandkicker View Post
    ....compression check???
    Thanks for that thought, but actually these engines seem remarkably healthy. Compression is 135 ish all the around.
    I do tend to think it is timing related. I'm not a pro at timing. Done a few cars but the timing indicator gauges (pointer tabs) on my motors do not have a mark for me to know where 0 is. What I did when I timed them was pull #1 plug and bump til I felt the compression blast and then referenced where on the pointer tabs the harmonic notch was as well as where the rotor was pointing. I did that a few times on each side to get a somewhat consistent starting point for tdc.
    Then, the confusion as to how many degrees each of the sharkteeth on the timing tab represented. It's been 4 years since I did this, but again, I got to a point where the engines fire instantly and someone told me that the timing had to be pretty close for that to be the case. Also, I have not operated my boat above 1500 rpms in all this time just because I have not wanted to pay for the fuel or risk stressing these old motors.

Similar Threads

  1. Twin Crusaders - Both bog down at 2200 RPMs
    By lazydaze in forum Crusader Marine Engine Forum
    Replies: 6
    Last Post: 08-12-2018, 02:47 PM
  2. Crusader 305 w/ Delco EST Not Achieving High RPMs
    By adam254 in forum Crusader Marine Engine Forum
    Replies: 4
    Last Post: 04-13-2015, 09:30 PM
  3. not achieving wot 1986 crusader 454's
    By sammi in forum Crusader Marine Engine Forum
    Replies: 5
    Last Post: 01-12-2012, 03:28 PM
  4. 454 not achieving rated RPMWhat do the experts think
    By major_tom in forum Crusader Marine Archive
    Replies: 50
    Last Post: 07-20-2009, 10:26 PM
  5. Under Achieving rpmbs wrong prop
    By markchiz in forum OMC Sterndrive and Inboard Archive
    Replies: 11
    Last Post: 11-01-2007, 07:38 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •