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79b Evinrude 115 Carb Issue

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stromzilla

Contributing Member
"My engine (115999R) c

"My engine (115999R) continues to idle poorly. We tried a set of carbs from a 79 Johnson 100 and it performed perfectly, so I believe we've narrowed it down to the carburetors. I have cleaned these things many times over. I can see fluid rushing out the idle orifices when I put water pressure to it. Is it possible the carburetors were assembled incorrectly i.e. brass stems facing the wrong direction? Could it be the idle jets are still dirty and should be replaced? The only thing I haven't done is remove the internal plugs which would give me full access to the idle orifices."
 
"actually,...if put in carb cl

"actually,...if put in carb cleaner,rinsed well...in wtr,then blown dry,...there is little need ,to have to clean manually...a flashlite,is a must..only the worst ones,do i have to use a tip cleaner on...never hurts to ck tho..."
 
"I have a feeling the idle ori

"I have a feeling the idle orifices on my carbs may need the manual cleaning. I've already had the parts in the parts cleaner several times and it still runs like crap. Assuming I need to do a manual cleaning, what can I use to get into the idle-orifices in the throat of the carb to get the crud off? And also, I'm assuming the plugs need to come off which would improve the accessibility to those orifices?"
 
"welders,cutting torch,tip cle

"welders,cutting torch,tip cleaner,...carefully...u dont want to enlarge the jets,...but ,it would take,one,rambunctous fellow!"
 
"Ok. Tomorrow I'll be pic

"Ok. Tomorrow I'll be picking up the tip cleaner set and I'm going to remove the plugs and get after it. The summer is sailing by, I've got a rebuilt engine, and I'm sitting here still screwing around with carburetors. There's something wrong with this picture!!"
 
"I removed the plugs, cleaned

"I removed the plugs, cleaned the idle orifices, replugged, cleaned the low/Hi speed jets, set the float level to 3/8", and it still will not idle without a partial choke or like it did with the carburetors off the 79' Johnson 100 . The part number on the carbs is 323352. Does anyone have any thoughts about this?"
 
"ur carbs,..r of a good design

"ur carbs,..r of a good design....there is something amiss,...news to u right :>)...set floats,level,...since u have an idle prob,it has to be an idle orifice prob....every tiny hole,must be ck'ed and dble ck'ed...have u used a flashlite,....i consider it a must,...one tiny hole,will give prob,..but it sounds like u have more than 1 tiny hole prob,..have u gone thru,the,linkage,and synchronization,..adj...mainly,in ur case,...that 1 carb butterflies,is not open,and the other ,closed...."
 
"I went over all the idle-orif

"I went over all the idle-orifices using tip-cleaners and flashlites. I looked at those things from every possible angle. They are not plugged. However, is it possible someone previously could've enlarged the idle holes? Would you happen to know what the dimensions are for the idle orifices? Also, wouldn't a larger hole allow for more fuel? I've synchronized the butterflys but perhaps I need to take a closer look. If one is off could it be causing my problem? It seems to me that if 1 butterfly was more open it would draw more fuel which doesn't lend itself to be the root-cause of my lean idle condition."
 
"look on evinrude.com and see

"look on evinrude.com and see if it lists jet orifice sizes,..cant rem,...if not,i would be glad to look it up for u,..email me tho,as i am hm now.."
 
"Orifices are not given in &#3

"Orifices are not given in 'diameters' but 'flow'.
Use the reference numbers given in the parts catalog, they are all there. If stated D53, get type 'D' with flow reference 53. To make it worse, each jet manufacturer may have his own flow chart, so you have to stay with the references given by OMC/BRP. The only place you find a complete chart with flow rate numbers and corresponding part numbers are in the factory work shop manuals. In the parts catalog, only the specific jet is stated."
 
"ok,i dont have the 79 series

"ok,i dont have the 79 series books,..i do,however,have 81--
the carb design is diff for the low spd system...therefore,specs on 81 would be diff,i'm sure...sorry...
I would recommend,purchasing the service manual (FACTORY),for ur eng..lots of good info in them..."
 
"In the 115 2 different jets a

"In the 115 2 different jets are listed:
0322936 #28
0317474 #27

The 100 use:
0323003 #25
Down in size (air) makes more fuel. As it was idling perfect with the 100 carbs, try to get a set of #25 and test!"
 
"Regarding orifice size...I wa

"Regarding orifice size...I was refering to the 4 holes in the throat of the carb that feeds fuel during idle, wondering if someone had reemed them to an oversize condition. However, all of that is moot at this point because I got the engine running this morning. JWB had mentioned earlier to double-check the carb synchronization so I did. When I first looked at it I noticed that both carbs were opened slightly with the linkage fully closed. So I allowed the butterflys to go fully closed on both carbs. Fired up the engine, cleared it and watched it idle smoothly all the way down to about 550 rpm, and I've never seen that since I bought it 3 months ago. What a wonderful sight/sound!!!! And I'm running the stock 27/28 idle jets along with the stock mains. By the way I had the carbs off 1 more time before I cranked it up...you can eat off of any component because it's so clean. Perhaps I can now say I have the cleanest RUNNING set of 79 115 carburetors in the world? Maybe too I should get my butt out on the lake to further validate this mess before I get too cocky. Thanks guys for your input. As I've said before, this site is awesome!"
 
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