View Full Version : My Last "Help Me" Thread
07-11-2008, 09:39 PM
Guys, it's about time to let the guys who get paid to be mechanics earn their pay. But before I do, I'm gonna give it one more shot. Here's the scoop:
79 MC S&S w/351W
My power valve went out in my carb so I replaced it with a new Holley 4160. The boat still wasn't performing when I replaced the carb. The boat is sluggish out of the hole and in turns and will not build RPMs. In neutral the motor will open up and quickly reach 2700 RPMs. When I put the boat in gear and place the motor in a pull, the boat will not come out of the hole and I can't get over 1700 RPMs and it takes a while to get there. Here's what I've done:
1)Replaced Holley carb w/new 4160
2)Replaced springs in timing advance
3)Installed new plugs and wires
4)Compression test which read 110, 120, 110, 110, 115, 110, 110, and 115.
What's next. Any advise would be greatly appreciated before I drop some cash to pay to get it right.
07-11-2008, 09:41 PM
prop???????? just throwing it out there
07-11-2008, 09:44 PM
I haven't done anything to the prop and it ran fine most of last summer. The problems started late in the summer and now here we are. However, the shaft does make a popping noise when I stop the boat and the prop is still turning.
07-11-2008, 10:07 PM
07-11-2008, 10:24 PM
Could your prop shaft Strut bearing or sleeve whatever they call it worn causing the shaft to bind?
I'd make sure the carb is adjusted properly first.
07-11-2008, 10:27 PM
Have you done anything to the distributor, like new cap, rotor, points, condenser, coil or even a EI conversion, gas won't burn in a engine w/o proper spark and timing.
That will be $42.50 and I accept PayPal!
07-11-2008, 10:34 PM
The distributor has been converted to EI, but I have not replaced the coild, cap, or rotor. Any suggestions on the best / cheapest place to get that?
Never mind what I wrote about points. The timing may need re-setting, since it's usually different when the points have been removed.
Have you looked at the spark plugs since you replaced them? Look for the color of the deposits and if they're close to white, the mixture needs to be richer. What does the exhaust smell like?
If the cap and rotor are more than a few years old, it's time. The coil can probably stay.
07-11-2008, 10:39 PM
It has electronic ignition.
07-11-2008, 10:39 PM
One simple path of least resistance, http://www.skidim.com/ or a local NAPA dealer.
Yeah, I saw that when I posted and you must have just beaten me to the punch, so I changed my original one since it doesn't apply.
07-11-2008, 11:07 PM
I removed one of the plugs and nothing looks out of the ordinary. The deposits are black but not overly saturaded so I don't think it's running too rich or too lean. I had a friend set the time last weekend but I didn't witness that. I bought a timing light today and intend to set the time tonight...just not sure about exactly what I'm doing. I clipped the red gator clip on the positive battery terminal, the black on the negative, and the lead over the #1 wire, but nothing happened. What am I doing wrong with the light?
07-11-2008, 11:11 PM
I pulled one of the plugs and nothing looks out of the ordinary. The deposits on the plug were black, but not overly saturated so I don't think it's running too rich or too lean. I had a friend set the timing last weekend, but I was not there to witness that so I bought a timing light today. I clipped the red gator clip on the positive terminal, the black on the negative, and the lead over the #1 wire, but nothing is happening. What am I doing wrong with the timing light?
07-11-2008, 11:12 PM
Sorry guys. Didn't think the first post went through.
07-11-2008, 11:18 PM
I would go back to basics..... Air, Fuel, Spark. Usually I start form the beginnings of each one aka fuel then lines then carb for fuel, air filter then intake and check ur manifolds for leaks for airflow. Then start getting into the nitty gritty form there. That's just how I troubleshoot stuff, GOOD LUCK
When it was running, you got no flashes?
Try checking the throttle linkage to be sure the throttle plates are opening fully.
07-12-2008, 12:28 AM
Here is a link to a post i did that had installation and tuning instructions for the 4160... I think your past htis but just in case.
07-12-2008, 12:43 AM
When it was running, you got no flashes?been a while since I had to use a timing light, but I would say you have it hocked up properly..............bad plug wire???
07-12-2008, 02:15 PM
When hooking up a timing light, there is an arrow on the clip that goes on the plug. Make sure it is pointing to the spark plug, or flow of current. Also most timing lights have a switch now a days. You can also use the light to make sure each plug is firing. If you have it hooked up correctly, and still no flash, check it on another wire, but only time to #1. You might have some plugs not firing. I had this problem, and it turned out to be the cap and rotor was all corroded underneathe from moisture
07-12-2008, 03:11 PM
Just a shot in the dark, had a similar problem with an older boat we had. ran fine in neutral, would not go under power and it was the fuel filters were clogged. I am no expert, but just my 2 cents.
Have no idea about the timing light.
07-12-2008, 09:08 PM
Just an update guys. Apparently the timing light I bought was junk to start with. A friend brought over his light and we had it set to 10* BTC in a matter of minutes. As far as the problem that I am having, I replaced the fuel pump today. I pulled the line off of the carb this morning and checked the fuel pressure and I only had about 3PSI (I'm no expert, but that sounds low). Either way, I went and bought a new fuel pump and now have about 5.5 to 6PSI. Is that okay? I'll find out what it does tomorrow when I put it in the water. Thanks for all of the help.
07-12-2008, 09:42 PM
07-12-2008, 10:11 PM
Just an update guys. Apparently the timing light I bought was junk to start with. A friend brought over his light and we had it set to 10* BTC in a matter of minutes. As far as the problem that I am having, I replaced the fuel pump today. I pulled the line off of the carb this morning and checked the fuel pressure and I only had about 3PSI ](I'm no expert, but that sounds low). Either way, I went and bought a new fuel pump and now have about 5.5 to 6PSI. Is that okay?
When you got the proper working timing light, what was your timing at BEFORE you got it to "10* BTC in a matter of minutes"? That could have easily been your problem right there...
While you were checking timing, did you run the RPM's up and verify that your mechanical advance is working properly?
3 PSI is plenty of pressure at the carb...IF it holds that amount even at full load. All you REALLY need is 1 PSI at the carb; just enough to keep pushing a little fuel into the float bowls when the needles open. IF you had 1 PSI at WOT, then you have enough. Now that you have replaced the pump, certainly that won't be a concern anymore...whether you actually need a new pump or not. 5.5-6 PSI is also fine. Anything up to about 7 PSI is O.K. Above that, your can start pushing the needles open w/the fuel pressure, and flood the carb.
07-13-2008, 09:54 PM
Found the problem. I've apparently spent a whole lot of money looking in the wrong direction (not that it didn't need most of the things that I replaced). I put the boat in the water today and was still having the same problem. I started pulling plug wires and "bam", I have a five cylinder; no fire on #2, #3, or #5. I have a distributor cap and rotor button ordered and I hope that the problem will be solved. Just so I'm not surprised, is there anything else that could cause the loss of fire on 3 cylinders?
The fuel pump is still a good thing to have replaced since the diaphragm can leak and send gas into the crankcase, so you don't have that to worry about. So, the sum of the replaced parts is:
Plugs, wires, fuel pump, (filter?), carb and you have a cap/rotor on order. Is this right? If your distributor is able to cause spark, all of the parts from the rotor to the plugs should make it hap'n, Cap'n. As I said before, plug wires can be checked for continuity with a multi-meter and a distributor cap can, too. This isn't an area where you want extra resistance.
07-13-2008, 11:01 PM
That's the sum of it. I did replace the fuel filter and I have ordered a cap and rotor. The cap won't be here until Thursday so I'll have to wait until then to find out. Too bad there's not a cap at the automotive stores that would work.
07-13-2008, 11:05 PM
should be....look in the FAQ's for part numbers for the 351
"Too bad there's not a cap at the automotive stores that would work."
Did you call NAPA?
07-13-2008, 11:17 PM
No sir. As far as I know there are no NAPA stores around here. All of them were closed then replaced with O'Reillys and Advances.
07-13-2008, 11:20 PM
Distributor Cap NAPA part # AL171
Rotor is NAPA part # AL163
Are these the right parts? My dist cap is a clip-down type.
07-13-2008, 11:26 PM
I can't believe that you didn't "feel" that misfire. That motor should be a "shaker" w/3 cylinders down!
07-13-2008, 11:29 PM
You're telling me. That's why I never suspected that. The motor was running smooth without a noticeable shake. Blows my mind.
You can lose 2 and 3 without a rough idle. Get after it and it's a different story, as I mentioned about the one I worked on and that one had lost 2 and 3. #2 had 0 compression and #3 had about 15 lb, basically because of it compressing #2 at the same time. Losing #5 in addition- maybe it was firing before but not now.
07-13-2008, 11:41 PM
hello, does your electronic ignition have it own 12 volt power source, if the ballast resistor is in the way it wont run right. I have the same boat and i made that mistake, ran a wire from the hot side of the resistor to the distributor and it runs great. just a thought, great boat, best ever made!! Mike 1979 MC Skier 19(S&S)red and grey
If I was in an area where O-Reilly's and Advance were the big guns for parts, I would talk to the manager and let him know that someone will sell the marine parts and it may as well be them. All they need to do is make it known that they want to sell marine parts and get to know boat owners. They could do a mailing to boat owners in the area, too. Have the people tell them what will be needed, with the understanding that if they're going to stock the parts, the ones who tell them what to stock should buy them.
07-13-2008, 11:56 PM
Yeah, I'm working on that with O'Reilly. I buy most of my parts for my Jeeps and Land Cruisers from them so they've been trying to work on getting some boat parts in stock. The problem is that there are no popular "watersport" lakes around here and not many people own these type boats so there's no real demand for the parts. There are several good lakes and marine suppliers around, but they're all 1.5-2 hours away so I can't just run over and pick up parts.
07-14-2008, 10:44 AM
I went to the local parts store this morning and they cross-referenced the NAPA part. The guy there is telling me that a Mallory 209M will work. The distributor is a Prestolite. Will the Mallory work? Has anyone ran across this? The correct dist cap is the 1306 on skidim.
One screws down, one clips on. He needs to know which one it is.
07-14-2008, 12:50 PM
My dist cap is a clip-down type.
So is the Mallory P/N you listed.
Looks like you might be in business with that cap.
07-18-2008, 08:53 AM
Half the summer, a half dozen skinned knuckles, several dozen temper-tantrems, and $1600 later, it's finally fixed (WOOHOO!!!). The mallory cap would not fit so I ordered a Prestolite from Skidim and it came in Wednesday. I put the cap and rotor on and...no dice. #2, #3, and #5 were still not firing. The last piece of the electronics puzzle that hadn't been replaced was the electronic ignition. I went and bought a new EI kit yesterday, installed it last night, and...back to a V8. I reset the time, changed the plugs, tightened everything down, and hit the water. WOW, that's the way it's supposed to come out of the hole.
Thank you guys for all of the help. I appreciate the patience, suggestions, and encouragement from all of ya'll. Now it's time to spend the rest of the summer playing in the boat, not working on it.
07-18-2008, 10:16 AM
Sweet!! Nice to finally lick a problem. Congrats on sticking with it. Now go have a celebratory ski!