'93 Yamaha 115 intermittent starting/stalling

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Been having lots of trouble on cold starting. Replaced key switch and starter and thought everything was ok. WEnt out a few weeks ago and it started and ran fine all day.<br /><br />But a week later went again. Started right away first try and away we went but now it seems to run for about 10-12 minutes and dies. After about 30 minutes it fires right up and it runs fine for 10-12 minutes then dies.<br /><br />Checked for fuel blockage but everything appeared ok. Checked kill switch and overheat circuit and that seems ok. Started pulling off all grounds on the engine and checked for corroded connects, etc., everything ok there. Completely unwrapped all of the wiring harness inside the engine to check wires, no problems there.<br /><br />Removed all coils and checked those grounds. Sometimes while cranking it may fire once or twice but nothing more.It might start just fine, run on the hose for 10-15 minutes, shut it down, then try it again and it may or may not start.<br /><br />Need this fixed soon for a South Padre New Years trip. Help!<br /><br />KEW<br />Seabrook TX
 

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Re: '93 Yamaha 115 intermittent starting/stalling

More info on this problem.<br /><br />Checked compression and all are 115-118. So compression problem ruled out. Check for spark and have none. On 3rd cylinder I got a little brief spark once but no more. Removed white wire on cdi and tried again but no spark.<br /><br />This leads me to believe there's something in the stator, regulator, or cdi. I'm inclined to eliminate the stator because last Thursday it did fire and run for a while and there is no visible sign of overheating or meltdown. But this might be wishful thinking.<br /><br />Can anyone tell me how to test those components? Still waiting for my Clymer's manual and I dont have the right multimeter for electrical testing.<br /><br />Thanks to all..<br /><br />KEW
 

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Re: '93 Yamaha 115 intermittent starting/stalling

Breakthrough.....<br /><br />Ok, I learned that the regulator is just for charging the battery and not the ignition system. But that's part of the DIY process. I still dont have my Clymer service manual.<br /><br />But, after reading every post I could find on this forum on these symptoms I thought of trying something, I picked up a can of CRC Lectra-Motive Electronic Parts Cleaner and sprayed a generous amount up into the stator. I spun it a few times, spray again, spin some more. Lo and behold it started sparking. Checked every lead and they all are sparking nice and blue. Unbelievable. A $5 can of electronics cleaner did the trick.<br /><br />But to do it right I want to take the flywheel off and clean it thoroughly. There seems to be a lot of debris in there like paint flakes from the flywheel and dirt. How do you break loose that nut on the flywheel? There is a couple of holes in the flywheel. Is that used for some type of lock wrench to get some resistance against to break that nut loose?<br /><br />It feels so good to make some progress.<br /><br />KEW<br />Seabrook
 

bigbrownbuku

Master Chief Petty Officer
Joined
Sep 17, 2004
Messages
885
Re: '93 Yamaha 115 intermittent starting/stalling

interesting. the nut is a normal right hand thread that requires a long breaker to crack.<br />the holes around the nut are for the puller bolts.<br />the flywheel requires that it be pulled from the center rather then from the outside like traditional pulleys. if you do get the right puller be sure to take care. i have seen flywheels jump 3 feet in the air when they finally<br />come loose.
 

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Re: '93 Yamaha 115 intermittent starting/stalling

Thursday am. Try to start and just touch the key with the normal startup procedure and it roars to life. Sweeet!<br /><br />Take it to the ramp. After a little hesitation it starts. Head out to the bay. Wind up putting about 20 miles on it including long 20 minute runs, then trolling, shut down for 10-20 minutes, fired right up with justa touch of the key. In short it ran flawless.<br /><br />So the question to you master mechanics out there, is just spraying some contact cleaner into the stator good pm or is this just a short term fix and a precursor to a deteriorating problem?<br /><br />One thing is sure. I now understand the mechanics of this engine better than I ever have. Much of which is from all the posts on this site. I did get my Clymer manuel yesterday so I'm now just a little bit more dangerous under the hood.<br /><br />kew<br />seabrook tx
 

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Re: '93 Yamaha 115 intermittent starting/stalling

Update 1/2/05<br /><br />After a 375 mile drive to South Padre I launched the boat, fired it up with no problems, idled out of the marina to the bay, up on plane for about 5 seconds and it dies. I try again and get a little fire but no start. BAck to the ramp.<br /><br />Yesterday, back in the driveway, I checked resistance on stator and they are within spec. Cant test CDI with the voltmeter I have according to Clymer. Checked ignition coils. Secondary resistance should be 2000-3000. 1 was 3300-3400 but the other 3 were 100,000 plus. I put on a spark tester and was getting some spark for about 30 seconds then it quit. This morning I come out and try again and now it has spark again. I try all 4 plug leads and they all are sparking. I put everything back together and it fires right up. It runs at fast idle for about 5 minutes and dies.<br /><br />I retest resistance on the stator and nothing has changed. I retest for spark and there's none. Does this sound like a CDI failure? I'm thinking the capacitor is weak and unable to store enough voltage to keep up with the engine.Or would the exceptionally high resistance on the ignition coils cause the CDI to "run out" of voltage? The Clymer manual says to test the CDI with the Yamaha Pocket Tester and if it fails take it to a Yamaha dealer and have them test it. Will they do That? Bench test a part? I have access to a Fluke meter. Will that work?<br /><br />Would appreciate any help on this.<br /><br />KEW<br />Seabrook TX
 

KEW

Cadet
Joined
Nov 30, 2004
Messages
19
Re: '93 Yamaha 115 intermittent starting/stalling

I ordered an ESI 530 peak VOM direct from ESI for $78. It looks identical to the one Mercury sells for about $110, If someone would post the stator and cd voltage outputs I would be greatful. Its a 93 C115TXRR.<br /><br />Did some closer checking on my ignition coils and found that the 3 with super high resistance had corroded plug connectors. I pulled them off and tested direct to the wire and they all measured just over 2000. Was wondering if I should replace with the OEM plug boots or alternative. The coiled wire connector is difficult to reinstall and fit into the 90 degree boot. Has anyone done this?<br /><br />Checked for spark from bare plug wire but still get none. Voltage test should nail this down.
 
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