1975 135HP no spark with plugs installed, PP4?

[RobsTV]

Boat and motor were pickled in storage for 10+ years. Engine is very clean under the cover, and looks more like a 1992 than a 1975, as far as aging.<br /><br />Started right up, and ran it for about 30 minutes before we shut it off.<br />Next day, no start, no spark.<br /><br />Have read the ignition trouble shooting steps, and discovered that I have no spark when spark plugs are installed. If I remove spark plugs, spark is great.<br /><br />Trouble shooting steps seem to indicate it is not powerpack related.<br /><br />Symptom trouble shooting steps show that as long as cranking RPM's are high (new battery cranks fast), and sensor coils ohm out fine (they read 8 ohms), then sensor air gap is culprit (removed flywheel, cleaned but did not re-gap yet).<br /><br />Don't have a DVA adapter yet. (have a couple Flukes, and will probably order DVA adaptor this week). Kill wire disconnected at pack during testing.<br /><br />Question is, how accurate are all the testing procedures for curing problems?<br /><br />Do other tests even need to be bothered with for above symptoms, or do the steps taken so far indicate that there is a great probabilty that setting the sensor gap will correct the problem? Without gap gauge, is there anything else that can be used, like a thin piece of paper, etc?<br /><br />With above symptoms, could Powerpack be ruled out since spark is good when no plugs are installed? Replacement Sierra is about $90 delivered, while OEM is $170 locally (Gary's). Is it wise to keep a spare PP? Will probably order Sierra PP this week as well. Sierra just as good (or good enough) as OEM?<br /><br />If sensor coils read 8 ohms, can they be ruled out as cause?<br /><br />If I am wasting time and money getting a powerpack and DVA adaptor to solve this problem, when a simple air gap adjustment will correct, I can have boat running today (if someone can provide gap gauge alternative method), otherwise I wait on parts to continue testing..<br /><br />Anything else I might have missed?<br /><br />Thanks in advance!<br />Rob

 

[ezeke]

Re: 1975 135HP no spark with plugs installed, PP4?

The description you give still points to battery weakness. You need 300 RPM to start that beast. I use a 650 and a 700- They have to be fully charged to do the job, even at that size. <br /><br />Feel the battery connections at battery end after you try to start, if they are hot, you may find the cables are corroded and will need replacement.<br /><br />Be sure to torque the flywheel back to 115 ft lb. <br /><br />Check to be sure the chokes are 100% closing electronically at cold start. <br /><br />When starting cold, open the warm up lever full, hold the choke switch on until the motor starts.

 

[OBJ]

Re: 1975 135HP no spark with plugs installed, PP4?

Exactly what ezeke said. When you remove the plugs, you gain the extra rpm needed because your not pushing into any compression.<br /><br />Give it a shot.

 

[RobsTV]

Re: 1975 135HP no spark with plugs installed, PP4?

Thanks for the replies.<br /><br />Battery is new 650, and seems to crank fast.<br />Will fully charge another battery 2 (800+), connect it together with battery 1, and see if that helps. Original owner did use two batteries, while we only tested with one new one. <br /><br />It did start that first day with the single new battery, although it was kinda funky. Seemed like no spark, and while testing for spark we felt it kick like other cylinders were now firing, then connected plug wire, and it started right up. Shut down and restarted a few times during 30 min test, and it seemed fine every time. Until next day, and now a week later, still no go. Charged battery between tests to make sure it was fully charged.<br /><br />Again, it seems like starter is cranking it well over 300RPM's. How on earth (or as the manual says how on this green earth) is this thing supposed to start with the included pull rope if needed?<br /><br />Negative cable end attached to battery was still very warm a couple minutes after starting attempt. Connection looks good on battery end. Will check other end for poor connection.<br /><br />Back to real question though.<br />Does the good spark with no plugs installed mean that powerpack is fine, and new one is not needed?<br /><br />Thanks again for your help,<br />Rob

 

[OBJ]

Re: 1975 135HP no spark with plugs installed, PP4?

The "warm battery" terminal is a little concerning. Means the starter is pulling a lot of amps to work. If the connections are clean and tight, you may need to open the starter and take a look at the brushes and commutator. Brushes can wear down and commutators get dirty. Results in poor contact and a lot of current draw.<br /><br />Just for grins, take a peek under the flywheel and see if you see any goo laying around. If you do, your problem could lay there as far as the spark is concerned. The stator is made up of the engines alternator, and charge coils for producing the initial charge needed for spark.<br /><br />I would also take a look at the rectifier and make sure it's good. While it dosen't have anything to do with the spark, it's responsible for battery charging.....turning AC into DC. Just covering bases.<br /><br />EDIT: Just thinking....the warm terminal...just how warm is warm? A lot of cranking could make it warm but not really warm (almost hot?) if the connections and starter are good....

 

[RobsTV]

Re: 1975 135HP no spark with plugs installed, PP4?

Thanks for the tips. They solved the problem.<br /><br />Negative cable that we connected during testing was for the second battery since it gave us extra length. primary battery was not connected, although cable ends were all attached. Cleaned ends, installed a single 850 battery as primary, and it now fires right up every time.<br /><br />Thanks again ezeke and OBJ, for saving me a lot of time and money!

 

[OBJ]

Re: 1975 135HP no spark with plugs installed, PP4?

OK Rob! And thanks to you for posting back with the fix. It helps everyone in the long run.

 

[RobsTV]

Re: 1975 135HP no spark with plugs installed, PP4?

Back again with no spark problems.<br /><br />Since last post, took boat out for it's first run time in 15 years, and it ran pretty good. (only 4800RPM WOT, but at 38MPH). It was mainly a fuel test and burn old fuel run (40 gallons of treated fuel). Noticed some things that we wanted corrected, such as smaller prop to increase RPM's (new post in prop section), and after a couple weeks of upgrades, went to take it out second time, and no spark.<br /><br />Removed 2 spark plugs, and still no spark on any cylinder. It was Sunday, and we were ready to go, so went to marine store and bought a new Sierra PP4 for $90, just to see if we could get a quick fix and save the day. Prior to installing, we tested old for spark one more time. Bam, it fired up and tried to run, even though two spark plugs were removed. Spark was back. Figured old one may be defective anyway, so we replaced PP with new one to see if problem ever comes back. Old is now an emergency spare. (as asked in another post, does good spark mean power pack is fine?). <br /><br />Looking closer at coils, noticed one with a crack. Then thought perhaps moisture got into coil, preventing spark (1 bad coil kills all 4 cylinders?), and since engine cover was off in bright hot Florida sun while we were at marine store, coil dried out enough to give us good spark again? Possible? We sealed crack as a temp bandaid, and took boat out for a good day of boating.<br /><br />Based on this, should we replace all coils? Are symptoms suggesting something else?<br />Or, could it have just been PP4 all along, and since it is now replaced, we are good to go?<br /><br />What do you think?<br /><br />Thanks,<br />Rob

 

[rodbolt]

Re: 1975 135HP no spark with plugs installed, PP4?

how come no one suggests a voltage drop test on the battery cables and solinoid nor a current draw test for the starter? all tests are quick and painless and actually pinpoint problems rapidly.<br /> and yes replace all 4 coils as they fail a lot.<br />when you said old fuel, how old is old? its very easy to smoke a piston with bad gas.\<br /> if the gas is bad there is NO way to ever rejuvenate it. aint gonna happen and I see many each year with smoked pistons due to aged fuel.

 

[RobsTV]

Re: 1975 135HP no spark with plugs installed, PP4?

thanks for the reply.<br /><br />Battery problems were solved by replacing battery and cables. Cables and ends no longer heat up when cranking. Cables and or ends were most likely culprit and checking for voltage drops would have found exactly which caused issue. But it's all good now.<br /><br />Don't know how old fuel was before we used it up.<br />Maybe about 2 years? Maybe 15+ years...?<br />We were not wanting old fuel to be in great shape, just wanted to burn it up during testing.<br /><br />Boat was pickled and in warehouse storage for 15 years from original owner, then was purchased 2 years ago by brothers neighbor. On his first trip out, (he had carbs rebuilt, and top end decarbed), and had gas problems, such as ball collapsing, then needed towed in, and parked boat for two years until we bought it. We added seafoam, then trailered boat home 300+ miles, which mixed seafoam somewhat. Tweaked motor a little on small external 5 gallon tank, to see how it ran, and it ran fine. Replaced ball and fuel line. Drained 20% of old fuel out, and added fresh fuel. Started right up. Used up all old fuel during 7 hour test session the first time we had it out. Ran it out of gas, then used backup 10 gallons of fresh gas we had onboard to get us back, and it ran fine.<br /><br />So gas is now new, and was new last part of our test. Changed fuel filter 3 times during test, even though it too seemed fine. Drained some of old fuel into glass jar, and it did not leave and deposits a couple days later after settling.<br /><br />38MPH on the old 135 in this old Wellcraft 20' seemed to be pretty good, so while it is possible, don't think any pistons are bad.<br /><br />The thing starts and idles nearly as good as any brand new motor. Fairly instant with no choke needed. Puffs some smoke the first 15 seconds, then clear.

 

[mitchell6]

Re: 1975 135HP no spark with plugs installed, PP4?

You might want to do a commpristion test just to see what you really got, 38 mph is slow for that motor but mostly your rpm's should be over 5000 rpm's

 

[RobsTV]

Re: 1975 135HP no spark with plugs installed, PP4?

Today's test complete after a case of beer.<br /><br />Forget about smoked piston and compression.<br />Happy to see 145 to 152 PSI compression on all four.<br /><br />Replaced cracked coil and checked link and sync with timing light at various speeds, and all was correct.<br /><br />But, could not get any speed after servicing.<br />Less than 3000 RPM. <br />Turns out plug wire below coil we replaced was bad.<br />Only one coil was in stock. We ordered other three.<br />After rearranging plug wires, and running with old SS prop, we were back up to 4900RPM, but at only 35MPH. Close enough. Must have been a tail wind last time when we hit 38MPH. Still need more RPM. Will work on prop after the rest of the coils come in. New 13.25x17 aluminum prop would only pull 4600 RPM @ 31MPH. I thought old prop was stock SS 13x19 but now I'm thinking it is also a 13x17. Will have it checked this week to confirm.<br /><br />So looks like coil(s) were the new problem, or at least made the PP4 behave strangely or fail.<br /><br />Thanks for all the input in helping figure this thing out.