| Author |
Message |
    
Kris Smith
Member
Username: bb84ss454
Post Number: 11
Registered: 09-2009
| | Posted on Friday, November 13, 2009 - 10:18 pm: | 
|
I just bought this and it starts - ok and with the warm up lever lifted it runs about 2000 rpm and it's smooth. However, when I let it idle down to around 800 it wants to die. Trying to keep it running and slip it into gear so I can go is very difficult. Once it does happen it acts like it's not hitting on all 4 cylinders. Once it gets up above a certian rpm it clears out and runs like a raped ape. I'm curious as to the chances of new plugs and fresh gas might make a difference? |
Dcramer
Advanced Member
Username: dcramer
Post Number: 192
Registered: 05-2008
| | Posted on Saturday, November 14, 2009 - 02:32 pm: |
|
New plugs and fresh gas are definitly the place to start.
After that, start with the basics. Check compression, clean carbs, syncronization and linkage adjustments including timing. |
Kris Smith
Member
Username: bb84ss454
Post Number: 12
Registered: 09-2009
| | Posted on Saturday, November 14, 2009 - 09:23 pm: |
|
I tried new plugs and fresh gas. Didn't actually help much. I was able to get it in reverse this time. I couldn't keep it running long enough to do that yesterday. Seems to run good from 1800 rpm and up. What is the gap on plugs for this motor? |
Dcramer
Advanced Member
Username: dcramer
Post Number: 194
Registered: 05-2008
| | Posted on Sunday, November 15, 2009 - 04:12 pm: |
|
Without knowing any specifics on the engine other than it's a 115, The best guess I can give you is 0.030" If it's CD ignition (MagFlash, Firepower, etc) you can run .040. Many of these were updated to .030 as well though.
It's likely the carbs, compression, or sync & link are out of whack. |
Kris Smith
Member
Username: bb84ss454
Post Number: 13
Registered: 09-2009
| | Posted on Sunday, November 15, 2009 - 05:00 pm: |
|
What is a "sync & link"? Does anyone have a pdf manual for my application? It's a 1973 Evinrude Starflite 115 Model #115393. |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5118
Registered: 11-2005
| | Posted on Sunday, November 15, 2009 - 07:22 pm: |
|
ahh yes,....great ol eng,...i had 2...on a lg hseboat.....dont worry about any timing issue,since its an idle prob...
and the prop term,is--link and sync....linkage and synchronization,of carbs to ign....it is not a nitemare on that eng....trust me.....a FACTORY service manual,avail everywhere and on this site i belive is ex valuable....but,...u dont have to go thru all of the l & s to cure a prob... |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5119
Registered: 11-2005
| | Posted on Sunday, November 15, 2009 - 07:23 pm: |
|
have u tried,..simply ..idling it up,w/the adj screw?.....have u ck'ed ur fuel....for wtr?...ex common now...put the required amn of seafoam,in fuel tank to take care of any 'slight' carb prob's....new plugs---ql77jc4...gap at .030...ck fuel for wtr...make sure timer base is rotating fully............all this,AFTER,comp,and spk test.. |
Kris Smith
Member
Username: bb84ss454
Post Number: 14
Registered: 09-2009
| | Posted on Sunday, November 15, 2009 - 10:22 pm: |
|
I can't just idle it up, it's missing below 1800 rpm. As I throttle it up it tries to die between 1500 & 1800 then it clears out and runs great. I'll try checking the spark asap. I know as I was buying the boat I noticed the spark didn't seem to be REAL strong, but I didn't have my tester on hand. |
jwbmarine
Senior Member
Username: jwbmarine
Post Number: 5120
Registered: 11-2005
| | Posted on Monday, November 16, 2009 - 06:56 am: |
|
ok...if spark ok,..i would clean/rebuild the carbs,..and i would also suspect a bad timer base wire where it rotates and bends.,ck ign coils for any cracks,and use ohmmeter on plug wires,...a suspect area,is in the boot,where the coiled term plugs into wire.. |
Kris Smith
Member
Username: bb84ss454
Post Number: 15
Registered: 09-2009
| | Posted on Monday, November 16, 2009 - 07:48 am: |
|
BTW I did change the plugs - (I used Autolites) & drained and refilled the gas tank with fresh 93 octane gas and ther red Evinrude 2 cycle oil. I'll try to check spark tonight. Thanks for all your help so far. |
Kris Smith
Member
Username: bb84ss454
Post Number: 16
Registered: 09-2009
| | Posted on Wednesday, November 18, 2009 - 06:37 pm: |
|
OK, I just came in from checking spark. I have a tester that I can set a large gap with. I pulled the wires off all 4 plugs and checked by hooking up the tester to one plug at a time and turned the motor over with the key. I set the gap at around 7/16". All four wires produced a bright blue spark. So, spark is not the problem. Now I'm leaning towards a rich condition. Maybe the floats are stuck in one carb? I do recall the motor running at slow speed and it had a strong raw gas smell. What do you think? |
Kris Smith
Member
Username: bb84ss454
Post Number: 17
Registered: 09-2009
| | Posted on Friday, November 20, 2009 - 09:49 am: |
|
Another thought, Is it possible to put power trim/lift on this motor? |
Kris Smith
Member
Username: bb84ss454
Post Number: 18
Registered: 09-2009
| | Posted on Friday, November 20, 2009 - 10:55 pm: |
|
OK, I pulled the carbs, cleaned them out, I did find a chunk of something in the bottom carb. I blew everything out with compressed air, put them back together and back on. I put the muffs on and fired it up. It seemed to run good and it idled down to around 800 rpm. I was able to shift into gear and rev it up a little forward and reverse. I shut it off and let it sit for a minute or two. As soon as I hit the key it fired back up and ran smooth. I guess that was it. If possible I'm going to take it out tomorrow to see for sure. |
Kris Smith
Member
Username: bb84ss454
Post Number: 19
Registered: 09-2009
| | Posted on Saturday, November 21, 2009 - 10:10 pm: |
|
I took it to the marina today and it started up and warmed up ok. Once in gear it ran a little better than at idle. It's still acting like it has a lean kick to it at idle, sometimes kicking hard enough to stall itself. The mechanic there said these motors always did run a little rough but that the more they get used the better they run. He suggested I run some sea-foam additive in the gas and that it might smooth out on it's own. He also said it sounded good and seemed to be a sound motor and that he'd be confident in taking it out and running it around. I guess alls well. Thanks for your help. |
