'65 40hp dropping lower cylinder

[dafox99]

guys,<br /><br />boat has run relatively flawless most of the summer. Put new coils and filed and set points in August. Kids went out and had to limp back today. Lower cylinder only hits about 10% - 20% of the time. I couldn't remember which cylinder the vacuum cutout switch grounds, so I disconnected that. No dice .. same problem. Sooo, unless I hear different, it's back to the ol' flywheel popper and check for a bad coil/points/connection/wire?

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

Did you check spark? If that's not what's bad, it could be a blown head gasket. Easy enough to check by pulling the plug and looking for signs of water (ie, cleaned plug or salt deposits).<br /><br />If it is spark, and it happens with the two magneto wires disconnected, it's got to be under the flywheel. Most common problems are contaminated points, primary side ignition wires worn through from rubbing, and cracked plug wires. I can't imagine it's a bad coil.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Thanks, Paul. I pulled the plugs .. they looked identical (sort of dark brown .. a little bit of deposit caking). They seemed a bit darker and "cruddier" than I thought they should be. I thought I was looking for sort of a milk-chocolate color, and minimal, or no deposits. I swapped the plugs, and it stayed in the lower cylinder. Guess I'm popping a flywheel.<br /><br />Oh .. forgot to mention. No, I didn't check spark, actually. Just heard a cylinder pick up and then drop periodically, pulled the top wire, and it wouldn't run at all. Put the top back, and pulled the bottom and it ran on the top one. Swapped plugs, and the bottom one was still dead. When I put both wires back on, it acted the same (ran on one, but would pick up the other 10% - 20% of the time) Assumed bad spark on lower cylinder .. yes?

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

Pretty safe guess I think. If the head gasket had blown there would definitely be a difference at the firing end. Usually there's little question. As for the deposits, that could be just from running at lower speeds. But you might want to try out the J6C plug next time for fun. I take it you're not running double oil (24:1)?

 

[dafox99]

Re: '65 40hp dropping lower cylinder

nope. 50:1. The kids were about 10 miles up the lake when the trouble started, so it had about an hour at 10 mph to get home .. maybe that did it. Will try to pop the flywheel tomorrow, but it's a combination of "honey do" day and the cowboys fighting for their life for 1st in the NFC east against the giants tomorrow, so may have to wait until the week. Thanks again.

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

No trouble at all. Tomorrow is Put winter wheels & tires on the car day.

 

[MCM]

Re: '65 40hp dropping lower cylinder

Good Luck Dave, on all three fronts do's, motor and the boys. Been a Bears fan since I was 'bout six though, finally playing like the "Monsters of the Midway" again

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Thanks!<br /><br />Bears are tough ... like watching Butkus again!<br /><br />Winter wheels and tires .. yikes. It was 83 here in Austin today. A little too warm for December for me.<br /><br />As far as cars go, yesterday .. did master cylinder and brakes on the '89 Trooper, and dropped the gas tank on the daughter's boyfriend's car (who lives with us ... ugh) to replace float as the gauge didn't work and I was tired of him running out of gas.

 

[tashasdaddy]

Re: '65 40hp dropping lower cylinder

the thrill of parenthood.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Well, this hasn't been a banner day. With half time coming up, it's 10 zip Giants.<br /><br />In addition, I've busted three bolts off in the flywheel trying to pull it. 1/4 20, 2 1/2 inch, shouldered zinc plated steel. All bolts are torqued down to the shoulder, pull is straight, and I'm holding the puller with a pipe wrench (instead of a big screwdriver on the flywheel teeth so I'm not twisting the bolts).<br /><br />Three separate efforts, each time, busting a different bolt. I torque the center bolt damn tight, and then pop the center bolt with a big mallet, then torque again .. torque, pop, torque, pop. I sprayed liquid wrench on the crank before the last try and let it sit about 5 minutes.<br /><br />I've been lucky and have been able to drill and easy-out the busted bolts each time.<br /><br />Will let it soak in liquid wrench today and get more bolts. I put the flywheel on myself in August per spec (100 ft-lbs, I think).<br /><br />Any ideas?

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

Pick up some "Grade 8" bolts for your puller. There's a big difference between those and your average hardware store ones (usually about Grade 2).<br /><br />Try the liquid wrench but clean the crank taper & flywheel meticuously before reassembling it. Oil will make the flywheel hub spread.<br /><br />I wonder if the flywheel key sheared a bit? That would result in weak spark and a really hard to pull flywheel. You may have to resort to heat.

 

[MCM]

Re: '65 40hp dropping lower cylinder

Take the nut off first just kiddin' Try some longer bolts.<br /><br /> EDIT: I like Pauls' advice better.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

There's a nut? Is that the hexy-thingy in the middle? Ahahahaha .. I crack me up<br /><br />Where's a guy git these double-throw-down super-bolts? Not sure Home Depot carries such a thing. Standard Ace Hardware?<br /><br />You know, I thought About the shearing pin thing, but thought it would completely shear and not run at all .. but maybe a tiny turn would weaken the spark and make this thing so hard to pull.<br /><br />17-3 now. Tough being a cowboys fan in the post-triplets era.

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

Those big twin flywheels aren't threaded all that much. Only about 3/4" deep. <br />You can get grade 8 bolts from a number of places, but not normally your local hardware store. Look in the yellow pages under fasteners - most the commercial suppliers also run a cash register. Just ask if they handle small cash sales first. Alternatively, just about any trailer shop or trailer supply store will have them. As will respectable auto parts shops. <br />I've seen Grade 5 fasteners at Home Depot (Canada) but no Grade 8.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Got it. Thanks.<br /><br />Will check tomorrow. The requisite mourning period for the Cowboys loss ends at noon, I can start right after that.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Well, no luck so far. Got the grade 8's. Soaked crank/wheel in liquid wrench. I'm over 140 ft-lbs and no movement. Something is probably going to break soon .. puller, more stripping or bolt breaking. The woodriff doesn't look like it's been sheared, but I'm not certain. I'm a bit concerned if I try more force, and break a bolt, I won't be able to drill those hard grade 8's out. <br /><br />Using same method I always have ... torque it down, pop crank with mallet, torque/pop/torque/pop <br /><br />So .. what next? propane torch on flywheel? If so, am I looking at ruining an upper crank seal? If we are voting for just continuing more force, I believe I can put a cheater on the breakover bar, but it just feels like something I don't want to break will.

 

[Paul Moir]

Re: '65 40hp dropping lower cylinder

I wouldn't go overboard on torquing the centre bolt. I forget what I calculated the flywheel thread failure force was but I think you're pretty close. (obviously I'm assuming a number of things about your puller)<br /><br />My advice would be to thread the flywheel nut on a few threads, torque up the puller, and leave it overnight. Often this trick will work & the flywheel will spring off in the middle of the night. The nut keeps the flywheel from ending up on the floor.<br />If that doesn't work, heat is your next best bet. It'll take a long while to heat up the crankshaft to the point where the crankcase seal will fail. I doubt it's even possible with propane. If you've got something hotter, use it.<br />If the crankshaft seal does get damaged, it's pretty easy to replace it without disassembling the engine. And you don't need any special tools if you use OBJ's method.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Got it. I have it torqued to 140 right now. didn't think about it popping off and into the lake. Only about 4 ft deep there, but I doubt my kids would enjoy fishing for it . it's awful cold water <br /><br />Think I'll go put the nut on.<br /><br />Thanks

 

[dafox99]

Re: '65 40hp dropping lower cylinder

all day (10 hours) at 140 ft-lbs, and it's still just sitting there. I walked by and popped it now and then, but more out of frustration than thinking I was doing anything productive. Put a "for sale" sign on it. Will try the torch tomorrow unless it pops off tonight.

 

[dafox99]

Re: '65 40hp dropping lower cylinder

Ok ... get a bigger hammer. Finally got the 10 pounder and decided to give it a big whack after trying to heat it with a torch with no luck.<br /><br />Finally popped it off. Everything looked fine except The lower plug wire was cracked at the clamp on the timing base. I got two generic wires, cut to length, sanded and re-set points, put back together. No fire at all. It occurs to me these new-fangled sillycone carbon fiber spaceage plug wires dont work by pushing a coil needle in one end. AND, they have built in resistance for noise suppression. I put one old wire back and it fires like a champ. In the short term, I'm repairing the old wire with some liquid tape.<br /><br />Now .. where do I get wires for this thing? Also, am I on track that this is the problem?