Clatter going into forward and reverse intermitten |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Posted: June-02-2015 at 4:03pm |
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I recently had a transmission swap done on a pcm 351, I had a bad oil pump on my 1:1 velvet and I swapped to a used in good working order velvet 1:1 that came from my parts motor. I had it done by a shop locally due to my lack of knowledge on transmissions and time. They performed the swap and when I dropped it off I said replace anything that needs it. Specifically the damper. They ended up using one of the two used dampers and I'm trying to figure out if it went south on me already? I've now timed the engine 3 times and got the new motor running very well so I'm fairly sure it's not engine related. What I'm getting is a rattle/chatter noise from the tranny/bell housing. Every post I've read says damper plate. However, it's putting a strain on the engine so much that it kills it most times if I don't goose it a little. I've yet to read of anyone else having it that severe. And finally which stumps me the most is it is doing it intermittently? Any help is appreciated. Btw I'll be doing it myself, I would rather eat the free repair and KNOW it's done correctly
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scootdogydog
Senior Member Joined: November-03-2013 Location: Central MA Status: Offline Points: 404 |
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did they align the prop shaft?
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JoeinNY
Grand Poobah Joined: October-19-2005 Location: United States Status: Offline Points: 5698 |
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It sounds like your engine is not in as good of tune as you think it is, could be as simple as you have the idle too low, or you adjusted the idle mixture in neutral and not in gear under load. A bad damper would not kill the engine, a really botched rebuild might but more likely is a not quite right engine tune at idle.
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Yes, I separated the flanges when I got it back and in the water for 24hrs. It is within .003
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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To where the prop spins freely? Because it's easy to dial in massive misalignment to within .003".
Agree with joe, engine tune is your culprit if your alignment really is good. Possibly combined with a bad damper. |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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It's possible I could not get to 10 btdc @600 rpms. The best I could get was about 13 any lower and it just sputtered and died. I then turned in each idle screw until it stumbled, then backed each out a 1/4 turn, then readjusted idle and repeated. Maybe I'm missing something. I'm still learning how to tune an engine.
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Could one of you direct me to a thread or tell me how to start back at square one as I'm entering the boat on what to start with first?
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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Sounds like tuning issues at a minimum. Try this:
1. Set idle mixture screws 1.5 turns out. Set idle adjustment to 700-750. 2. Set timing to 10-12 initial. Check final while you have the light out (should be 30-35 all in by 3000rpm). 3. Go back and dial in your carb. Adjust mixture screws for the strongest vacuum while at idle under load (in gear on the water). Readjust idle level to 650 while in gear. Make sure neutral idle isn't much higher (750 max) or that may be a sign of other issues. |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Ok, a couple questions...30-35 max at 3000 rpms is at the dock I'm hoping? ;) as far as the idle mixture and idle screw do I leave it where it runs decent in neutral then go into gear THEN adjust idle screw or mixture screws first? That's where I get confused
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Sorry one last question, I'm going on vacation and wondered if I should order a damper so it's here when I get back? Or would you advise doing the aforementioned items first?
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Joel Tim's question is a good one. You were asked if they aligned the engine to the shaft and you did check that it's within the .003". However, is the strut aligned with the shaft??? It all starts at the strut!! |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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I could put it up on a lift to check it. Now that you mention that I've been getting a considerable shaking going on in gear. I assumed that it was The damper and or engine shaking. I will start there. This engine was a used pcm that I had bought last fall and I had to move the mounts around a lot compared to my old motor. Thank you for mentioning that. It could be binding up on me and it's causing all that extra stress. Shoulda kept my mustang 😖, this boat has brought nothing but headaches
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Joel,
When you got the .003" difference between the coupling faces, did you do the "quick check" for shaft straightness by rotating the shaft in 90 degree increments? |
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SNobsessed
Grand Poobah Joined: October-21-2007 Location: IA Status: Offline Points: 7102 |
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Spievy - Are you sure all cylinders are firing?
If there is any question regarding the health of the damper- they don't cost much & are mission critical . . . |
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“Beer is proof that God loves us and wants us to be happy.”
Ben Franklin |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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I am not familiar with the "quick check" I did rotate the shaft in 90 degree increments during the alignment and rechecked my gap. If you have a trick to check it I would love to hear about it
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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The engine runs excellent at idle so I didn't think to check all the cylinders 😟
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74Wind
Grand Poobah Joined: August-02-2011 Location: Georgia Status: Offline Points: 2101 |
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These guys are the wizards, but to my understanding if it were the dampener it would rattle every time, not intermittently, and also mostly just in reverse
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1974 Southwind 18
1975 Century Mark II |
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DrCC
Grand Poobah Joined: April-12-2004 Location: at home Status: Offline Points: 2867 |
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Here's what Joe said: (except he didn't use all caps like I'm going to)
"YOUR IDLE IS TOO LOW" 650 in gear is ideal. If I turn mine down to 600 it clatters. And mine does run absolutely perfect. Shaking ??? Have you looked at your propeller ? Bent or missing a blade ? How old are your plug wires ? |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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If you rotated the prop shaft and checked the difference after each rotation, then you did the quick check. If the shaft is bent, any clearance difference will follow the rotation. |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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idle is set at 650. If I don't goose it, it clatters and dies. Prop is brand new as are plug wires, cap, rotor, plugs and electronic ignition ( which I am curious whether it's to blame??). I replaced the strut bushing with a vesconite when I redid all the stringer work. I did not touch the strut or shaft.
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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I'm planning to start with the strut to shaft alignment, then motor to coupling alignment and see if it helps. Then move on to the timing and carb adjustments after verifying all 8 cylinders are firing. Sound like a decent plan?
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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Always do timing first.
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Gotcha. Thank you Tim
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DrCC
Grand Poobah Joined: April-12-2004 Location: at home Status: Offline Points: 2867 |
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Shake and clatter??? Plug wires crossed???
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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I will double check that. I checked and rechecked that ten times when I originally put it in but who knows I've pulled them for fogging and checking plugs since then.
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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Well today turned out to be a success! I started with my strut to shaft alignment and then to shaft, motor alignment and they were both spot on already. I started it up and double checked all cylinders were firing with my timing light. I then took each mixture screw to 1 1/2 out fired it up again and timed it to 11 btdc @750 rpm in neutral. What I wasn't doing initially the last several times was adjusting up the idle screw to get it to run at that time. Rookie mistake 😳 Once that was done I snugged up the distributor hooked up the vacuum gauge to the pcv port put it in gear and started my adjustments. After several up and downs to each mixture screw and idle screw adjustments the best I could get was about 13.5. Each mixture screw is I would guess pretty much where it started give or take an 1/8th or so. It ran excellent, no clattering at all and I was able to get 750 in neutral and 650 in gear. I really appreciate all the help!!
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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I hate to have to continue this thread but my issues seem to have not gone away. For an hour run I had no issues, it ran perfect. This past week I took her out and it started up fine, idled well in neutral and under load. I ran it for a bit at WOT, then as I returned to idle after a few moments it started coughing and clattering again and died. Started it back up, idled in neutral pretty decent put it in gear and same problem. I limped it back home and decided to order a rebuild kit for the Holley and rebuilt my first carb. I never knew it's condition when I bought the motor so I figured it's a cheap item to rule out. It went pretty smoothly I thought, a lot of YouTube and threads from here and I was confident I did a good job. I reinstalled it started at 1 1/2 out on each mixture screw, hooked up the vacuum gauge again and got to a 14 which from what I've read is possibly a sub par number?? Anyways, it was idling good in gear and I took off it ran good wide open. I started and stopped 8-10 times and it ran perfect then once I hit a channel I idled through and a minute in it started doing it again. I'm at a loss 😤. I have a pertronix ignitor 1 on it with a 40000 volt pertronix coil on. It seemed pretty damn warm but I'm not sure how warm it should be. I'm not sure if it's an ignition problem possibly or if it's just a tired motor in need of a rebuild? Any suggestions I certainly appreciate. The issue never seems consistent so it's hard for me to know what to look at next. I'm happy to put points back in and try them but I don't know much at all about them
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Joel, This was going to be my suggestion but you've already thought about it. If you can handle a carb, you won't have any problem setting the dwell. |
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Spievy79
Groupie Joined: March-24-2014 Location: Fort Wayne, IN Status: Offline Points: 46 |
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from reading it looks like I would just need to pick up a dwell meter then? I already have the points and condenser from when I bought a new cap.. However I don't know that I know where the plate is. May have been misplaced?? Is that an item I might be able to find locally? Or perhaps I have my other prestolite distributor that I pulled which has the screw down cap though. Might that plate work?
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21169 |
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The points plates should swap between Prestolite styles. Otherwise you're probably out of luck... That plate can be hard to find. The commonly went in the trash when people converted to EI. Makes swapping back difficult if you didn't hold onto it.
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