I have an '89 with the M25XP. Manual says 3200 is the max RPM. I was perusing the forum here and read a bunch of threads about cruise RPM and speeds, etc. I realized that my tach reads 25-2600 RPM at WOT. I'm pretty sure that's the way it's been since I've owned the boat (2 years). I know the tach can be less than accurate, so I ordered a laser tach from amazon to see what it's actually turning.
My question is...If it is indeed turning this lower speed, is it just a matter of adjusting the throttle set screw on the engine until it's reaching 3000-3200? I looked at it and it has plenty of room to be adjusted for the throttle to open wider. Secondly...can this be done at the dock in neutral, or should I be in gear out on the water? The engine runs very well other than this. I've not had any issues with it at all. TIA!
Tim
Tim : "My question is...If it is indeed turning this lower speed, is it just a matter of adjusting the throttle set screw on the engine until it's reaching 3000-3200? I looked at it and it has plenty of room to be adjusted for the throttle to open wider. "
YES, MAYBE Just loosen the screw on the cable stop and see if the throttle arm will move and give you a higher RPM!??!
A thought
Quote"My question is...If it is indeed turning this lower speed, is it just a matter of adjusting the throttle set screw on the engine until it's reaching 3000-3200? I looked at it and it has plenty of room to be adjusted for the throttle to open wider. "
Tim,
NOFirst you have to determine what the speed actually is. That's first.
If indeed at WOT as it is now, it is truly turning at 3000 (or 3200, mine's 3000), THEN and only then you have a choice.
1. Play with the back of the tach in the cockpit and see if you can adjust it.
2. Don't bother, just make up a handy dandy cheat sheet where 2600 = 3000 (or 3200) and all the in betweens.
In the big scheme of things it simply doesn't matter.
The very LAST thing I would do is adjust the throttle set screw. After all, once upon a time they adjusted it at the engine factory.
If, however you feel you are losing speed at WOT (real) because of this possibly phantom 400 or so rpm, then, and only then, open 'er up.
Good luck.
Can the RPM test be done in neutral at the dock, or should it be under load out on the water in gear?
Tim,
You can test RPM in gear under load in your slip if your dock lines are good and you've got fore and aft lines on both sides. I've run mine up to about 2400 RPM, which is my normal motoring cruise in the slip with no problems. It makes doing checks easier when you can jump on and off the boat.
I do not see a difference in the rpms at WOT out of gear, in gear tied to the dock, or out in open water.
Stu,
You're probably right but there may be a difference in max achievable RPM under load(in gear) vs. no load. I don't know since I've never found the need to test for a difference between the to. I just mentioned it so Tim could run tests without the need to take the boat out.
Tim : I assumed that with your laser tach you were first going to look at the correctness of your engine tach!! You did say that in your opening post!!
Mark the throttle cable as to its present position, start the engine, loosen the throttle cable stop screw, move the throttle lever on the engine FWD and see if you actually increase the engine RPM ?? Then decide where you want that throttle to be set at.
That throttle adjustment screw was placed where it is by someone at the Catalina factory after the pedestal and engine were installed. It should (maybe?) have been checked while the engine was running (boat in the water) by the dealer???
Then make yourself a small chart of 4 or 5 different RPM settings on the engine tach and the actual RPM from the laser tach. The real important setting is your 80% power for cruise.
You can fool around with the dip switch settings on the back of the tach instrument, but I've had little success with doing that!! There is quite a formula for those dip switches!!! (wrote a Mainsheet tech note article on those dip switch settings)
Kevin brought up a point. I believe that in gear the boat RPM might start out lower, but as the boat speed picks up (inertia) the RPM will stabilize maybe a few RPM lower than when in neutral?
A few thoughts
Ron, yes I'm going to compare tach RPM Vs Laser tach next week when I get home. Just ordered one from Amazon. My concern is more about whether I've been actually making the published 3000-3200
at WOT. It's always shown about 25 or 26 on the factory tach.
I'm on my way to Europe right now, so after I get back Monday take it out and check with the laser. I'll write down the RPM corrections and report my findings.
Thanks all for the advice
Tim : You might lookup that article I wrote on the Tach Dip Switch settings, because I have a picture of the Default settings (M25XP with stock alternator) in that article. A PO just might have changed them!?! Also that formula for settings of a new alternator with a different pully size!!
A lot of information in these old Mainsheet tech note articles!! :clap
A few thoughts
Tom, the Teleflex tach manual is in the tech wiki, under manuals.
Do we KNOW that the factory "screwed with" the adjust screw, or was the cable simple attached to the engine exactly how it came from the other factory (Oshkosh)?? If we don't know the procedure I'd think it's a huge jump to say CTY adjusted anything, and simply started er up and checked the tach that there was some reading at all, not necessarily accurate.
Quote from: KWKloeber on August 18, 2021, 09:23:32 AM
Do we KNOW that the factory "screwed with" the adjust screw, or was the cable simple attached to the engine exactly how it came from the other factory (Oshkosh)?? If we don't know the procedure I'd think it's a huge jump to say CTY adjusted anything, and simply started er up and checked the tach that there was some reading at all, not necessarily accurate.
I've read every single C34 tech note, from as early as 1987 before they even called 'em tech notes. While your binary choices, Ken, are quite possible, i.e., they did or they didn't, I find it hard to believe that they did nothing. Why? Because in all of those years I did not ever read of a recurring all encompassing repeated situation where C34 skippers were ALL complaining that the WOT on their engines were all of whack, high or low. I am quite sure Ron Hill would have reported THAT glitch!! The consistent reports were that it was 3000 and that's pretty much what everyone reported.
It could well be that CTY just slapped 'em in and depended on the engine's builders to have set the MAX set screw properly. Maybe give 'em a little credit for trying or checking?
So, yeah, I guess you're right again, still bashing the builder, who just happened, by chance, accident, serendipity, witchcraft and voodoo to get 1801 hulls and engines built that just by happenstance all are correct.
I should be so lucky. :D
Quote from: Stu Jackson on August 19, 2021, 05:53:04 PM
So, yeah, I guess you're right again, still bashing the builder, who just happened, by chance, accident, serendipity, witchcraft and voodoo to get 1801 hulls and engines built that just by happenstance all are correct.
I should be so lucky. :D
Stu,
:donno:
I don't have one CLUE what you are babbling on about except, per usual, trying to blow something way out of proportion?
If I was a builder (CTY) and a component (engine) came to me to install and the engine mfgr set to specs -- I wouldn't think that my attaching a cable required "setting" anything -- so I wouldn't want to screw with it.
So my wonder was, did CTY adjust the engine after installing the cable? Or if something is amiss, might it have shipped from Oshkosh that way? Or did a PO adjust something? Or (as you mused) is the tach off? Or, is the governor getting messed up. Or..... (insert another cause.)
That's why I ASKED, and thought maybe someone knew for sure whether CTY did further adjustments. I have no clue why you would connect adjusting or not adjusting has anything to do with bashing CTY. And it has nothing to do with Tech Notes, or every boat that came off the line having an incorrect setting.
Get back on your meds. Please.
Update on the RPM discrepancy. We took the boat out and compared laser tach with cockpit. Most RPM settings only varied by a 50 or less, full throttle (obtained by me moving the throttle on the engine) was 3000. Looks like I just need to adjust the cable so the throttle on the binnacle can move the lever (engine) all the way to open. Looks like all is well. Thanks for the info! Now on to the next project!
Quote from: TortolaTim on August 24, 2021, 12:36:35 PM
Looks like all is well.
Isn't it
GREAT when you discover that things turn out to be, whew!, that simple. 8) :thumb:
Troubleshoot, troubleshoot, troubleshoot - before replacing, adjusting, and tinkering
That's my story and I'm stickintoit.
Tim : Just like I told you, I am not surprised!! :thumb:
A thought :clap
Good to hear, Tim. And thanks so much for checking and taking the time to let us all know. Not only do you know and can set aside your concerns, but we have all learned something. And Catalina got it right yet again. :D
I like a good tool as much as the next guy but I have a cheap easy way to verify any RPM with a strobe.
I found a free app (Iphone) used to verify RPM on a record player. Adjusting the RPM on the application to match a paint/chalk mark on the crank pulley to confirm rpm. Or setting the engine RPM and matching the App to that RPM to confirm accuracy. Confirm all to the tachometer.
You could see about turns of the driveshaft or rotation speed of the alternator etc. I deleted the app but it was good for confirming that my tac was in sync with actual RPMs.
On this post topic. My bottom and assume prop were so dirty that I was only able to get to about 2600 RPM at full throttle a few years ago. definitely dragging the works down.
Brent
Ken, Your adolescent comments are totally inappropriate. I think you owe Stu an apology.
If you can't say something positive, don't say anything at all.
Paul
Hi, have followed this carefully as the set screws on my M35 have both a wire and plomb-seal. Max rpm I can reach with WOT is tops 2100. Cruising speed is depending on conditions anywhere 5-6.1 knots with a temp of around 185-190.
Seems to be this setting has been in place for ever!
Should I change the screws to get higher rpm and possibly speed?
Motored from Annapolis to Rock Hall last Tuesday (before IDA storm came around) in flat 3 hours mooring ball to dock.
Thank you for advise.
[edit: PS, 185-190 is too hot to run in salt or brackish water. You might also troubleshoot why -- and verify that your TStat is opening and is the correct one (160F) for salt and not (180F) for fresh water.]
Bo
I think the same answers/replies as below re: Tim's problem probably also pertain to your 35.
The key is to first confirm that the tach is reading correctly (you are actually running 2100.) As I said previously:
Quote from: KWKloeber on August 18, 2021, 09:23:32 AM
.....did CTY adjust the engine after installing the cable?
Or if something is amiss, might it have shipped from Oshkosh that way?
Or did a PO adjust something?
Or is the tach off?
Or, is the governor getting messed up.
Or..... (insert another cause.)
Quote from: KWKloeber on September 07, 2021, 09:28:51 PM
[edit: PS, 185-190 is too hot to run in salt or brackish water. You might also troubleshoot why -- and verify that your TStat is opening and is the correct one (160F) for salt and not (180F) for fresh water.]
Can you elaborate why there should be a difference in Tstat temp for salt and fresh water? I cant sort out why they should be different.
Quote from: waughoo on September 07, 2021, 10:33:28 PM
Can you elaborate why there should be a difference in Tstat temp for salt and fresh water? I cant sort out why they should be different.
i'm no expert, but i believe the salinity of the water changes it's boiling point.
QuoteMax rpm I can reach with WOT is tops 2100. Cruising speed is depending on conditions anywhere 5-6.1 knots with a temp of around 185-190.
First thing that comes to mind is over-pitched prop. Do you know the pitch? Try, transmission in neutral full throttle, a few seconds or a little more, what is your RPM's. That checks your governor, if it's not to spec check the tack with hand-held laser tack. Sounds to me that there's a number of issues that may or may not share a common cause.
The first thing I would address is the temp, then check/verify the max RPM. The very last thing I would do is break that governor seal.
Jim
Quote from: waughoo on September 07, 2021, 10:33:28 PM
Quote from: KWKloeber on September 07, 2021, 09:28:51 PM
[edit: PS, 185-190 is too hot to run in salt or brackish water. You might also troubleshoot why -- and verify that your TStat is opening and is the correct one (160F) for salt and not (180F) for fresh water.]
Can you elaborate why there should be a difference in Tstat temp for salt and fresh water? I cant sort out why they should be different.
Sure but wow - This thermostat issue has been discussed umpteen times herein and is in the Westerbeke engine Service Bulletins and on the TechWiki.
"Our" Kubota engines that went into landlubber tractors and other industrial end-user equipment ran 82C (180F) thermostats. Diesels are more efficient/run better at higher temp but in salt water higher temp causes a precipitation of salt compounds in the cooling path. :shock: Temperature is ESPECIALLY important in seawater-cooled blocks such as the original Atomic-4s, early small Universal diesels, etc., because the deposits end up in the internal cooling paths/ports and can ruin a day of sailing. :cry4`
So somewhere early on Universal Oshkosh figured out to not use the 82C OEM Kubota TStat (probably spec'd Kb to supply a 72C one or sourced it in the US (as an aside, note that our TStat caps are different than equipment with radiators, and could have been mfgr'd here or supplied by Kubota.)
There's several mentions on here about the seawater-injection wye above the muffler getting caked with deposits and partially/totally blocking the flow. Check the Service Bulletins (Wiki
Manuals page) - 160F is the Westerbeke-supplied TStat (also available from Kubota and aftermarket.) In fresh water of course there isn't that problem so the higher TStat (180F, Kubota and aftermarket) can be used. (IMO **should** be used.)
This is a water-cooled riser (not the Westerbeke brand) that had been 100% blocked with deposits - note that in this scenario salt water is hitting the hottest area, right at the engine exhaust discharge before the two mix. That's somewhat analogous to the injection wye location.
(PS: I can't cite the original source, but the pic (and similar) are on various member forums/sailing sites/Moyer A-4 forum.)
Thanks... I would totally understand if it were a raw water cooled block, but hadn't figured out how it made sense in a fresh water cooled system. Thanks for the detailed explanation.
All : Oshkosh did run the engines after they were built. I believe what you are asking - did they set the governor stop during that run? .... Don't think so???
I'm most certain that on the production line floor "Paco" was told to attach the throttle cable from Edson to a measurement of (?) and then tighten the set screw. It would seem to me that it should have been the dealer that checked the engine settings during commissioning!! Don't know "who" put on the lacing wire with the lead seal on the throttle stops???
Just don't think that I'd build a engine and on its first run rev it up to max rpm!!
FYI, On aircraft engines you do not do that. That's why the first takoff is so hairy!!! - that engine is only run at reduced (cruise) power for the 1st hour running!!
A few thoughts
Thank you for the feedback.
Prop is a 3 blade Michigan Sailer 8/89 15RH12.
I think I read somewhere that the cruising temp for the M35 was 185-190...
The rpm gauge is working but the hours have not moved since we bought the boat (11/2020). 1045 hours on the numbers, who knows could have been 1045 for the last teen years.
Quote from: BJeansson on September 09, 2021, 07:48:00 PM
Thank you for the feedback.
Prop is a 3 blade Michigan Sailer 8/89 15RH12.
I think I read somewhere that the cruising temp for the M35 was 185-190...
The rpm gauge is working but the hours have not moved since we bought the boat (11/2020). 1045 hours on the numbers, who knows could have been 1045 for the last teen years.
The listed ops temp is 165-195 - that's from a Wb reprint of the original Univ Oshkosh manual/data so I suspect it may embrace salt and fresh water use. Naturally seawater temp affects it.
As a ref point I normally run 160 with my 3 cyl (unless I get an air lock) so I would expect a 4 cyl to bring that up a bit but not 30 degrees.
I'd check the flow path for salt deposits - if there are, reduce. If none then run hotter but check it on a schedule.
Guys : The Michigan Wheel props that I have seen have a much wider (cord) blade than the Catalina OEM Sailor Props!! I've posted this MANY times.
A few thoughts
My throttle controls 'slip back' at higher rpms.
Up to ~2300 rpm, the throttle lever stays where I put it.
It will rev higher, but will slip back to ~2300-2400 with the throttle lever physically moving back over a few seconds.
Would love some suggestions where and what adjustments/inspections I should make to resolve this.
Is it the cable itself, the lever at the binnacle, or some other adjustment?
Edit: Seems it can be fixed either way as per KWKloeber's link below. Either tighten the friction screw for the lever in the binnacle or add a 1/4" clamp to the throttle cable in the engine-bay to increase friction. One requires compass removal, the other is easier to adjust in the future. And when I went to install a clamp on the throttle cable, I discovered there was one in place already. I tightened it a smidge, and now my throttle holds all the way to WOT.
QuoteMy throttle controls 'slip back' at higher rpms.
Common problem has been discussed here before. Try a search. My temp fix is a rubber band wrapped around the guard tube and back to the lever. Then when I have time, take the compass off and tighten the bolt to add friction to the lever. There have been other fixes discussed.
Jim
try https://c34.org/bbs/index.php/topic,9973.msg76336.html#msg76336