Evinrude 1986 225 Carb flat spot/stalling

[Captain Koz]

hello,
I am stumped. I have a 1986 225... new stator, timing base, VRO pump and power packs, carbs rebuilt, good compression (almost 110 lbs per). It idles a bit rough at times and sneezes and sometimes stalls. This is corrected by bliping the choke a bit. Secondly when i throttle up, it will let me go about 1/4 throttle, then start to stall, then I blip the choke again and then I can procede further with half to full trottle. It will allow me to stay above that throttle point and within that throttle range with no problem. As soon as I drop back past 1/4 throttle and try to trottle up again, she starts to stall until I hit the choke. Sounds like the low speed circuit. Thats what I thought. I took the carbs apart and cleaned them again and even ran a wire through all the emulsion tubes and thru any hole I could find. The problem doesnt go away. I even ran an external fuel tank to weed out a fuel/air leak and that had no results. The guy at the shop thought it was the emulsion tubes so I cleaned them with a wire and there is still no change. As a last resort I am thinking of jeting the carbs richer. I think there may be an air leak somewhere that is only affecting the low speed circuit. Is it advisable to jet them a step up? Also, which is the current low curcut jet... the 14 or the 20? and if its the 14, should I go to # 15, 16, 17? Fuel is new. Have a water seperator. Just a lean flat spot that I do not know what to do with. Please help.

 

[tashasdaddy]

Re: Evinrude 1986 225 Carb flat spot/stalling

1st did you use rebuild kits on the carbs? did you remove the jets and clean?
http://forums.iboats.com/showthread.php?t=244013 all of these steps? have you tried having some one pump the primer bulb on the fuel hose, when it does this? did you do a link n sinc after the carb rebuild? just starters questions?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

Thanks for responding. Yes, I used rebuild kits from Evinrude, soaked the jets, wire-cleaned the emulsion tubes, sprayed and blew everything out prior to assembly. Through it all the carbs were squeaky clean. No crap, goo, dirt, sludge...nothing, very clean. Changed the gaskets behind the throttle assemblies, changed the choke feed hoses (thought they may be leaking), changed the recirculation hoses, synced the butterflies, checked compression and timing (test tank at 3800 rpm with a test wheel)... still a 1/4 throttle flat spot as of last night. Same symptoms... decient idle, good 1/4 throttle, starts to stall just after, hold choke for 2 seconds, motor wakes up, then i can proceed with the throttle without any issues at all. I even suspect that the entire idle thru 1/4 throttle is a bit lean because it is not quite as smooth as 1/2 throttle to full ( a few blips of the choke clears up everything). I want to rejet to see what will happen. what "steps" in jet sizes should i try? They are a #14 and a #20 for the low and mid circuit. Should I go to 16/20? or 16/22? or 20/26? I will have to pay about $7 a jet (times 6) per trial which sucks but I wish to do it myself instead of bringing it in. Id rather do it the hard way (myself) then the expensive way (dealer)... times are tight!

 

[mikesea]

Re: Evinrude 1986 225 Carb flat spot/stalling

I worked for a powerhead rebuilder 10 yrs ago.I recall jettting problems on some of the looper engines ,especially after rebuilding and oversizing the bore.What I cant tell you is the sizing.But,if you wish to play around,you dont need to buy new jets.You can buy a small drill index,in the range of your jet sizes.If you then want to go smaller,simply solder the backside of the jet and then drill to your desired size.A dremaltool helps or a hand drill I have one that is like a large pencil with a chuck for small bits,great to drill through lead.Be sure to scratch up the brass surface and use flux and solder for plumbing sweating copper ,if you are familiar.Good luck.I recall guys putting toothpicks in the jets,so oversizing might not be what you want.I dont know the chemistry there.

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

If you go bigger on the low & mid jets you'll make it leaner. You'll need to downsize to richen it up.

Did the motor ever run without this flat spot?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

Thanks for the advice guys I really appreciate it. Ive had the motor since september and despite all that I have listed as changed parts and upgrades, the flat spot NEVER went away. Thank you for the info about jetting down to richen. Ive heard that once before and I didnt think the guy knew what he is talking about, but now that it is said a second time i am puzzled and need help grabbing the concept.... The low and mid jets on these regulate air flow thru the emulsion tubes which pull fuel out of the bowl... so wouldnt more air equal more fuel through the venturi? So what your saying (and the other guy that said it) is to go with a smaller jet to let in less air... but then why doesnt that mean less fuel as well? I guess the explaination isnt as important as it working. So, with that said, from a #14 do I go 13, 12, 11, 10? I had it out tonight and im pretty sure I wont be messing with the #20 just yet. Its definitely first 1/4 throttle thats a mess. I know the powerhead was rebuilt at some point so its possible it was bored over. Wish I knew. Great advice on the jet drills. Im going to google them to see where I can grab a set. Great advice as well on sweating/redrilling a jet to size it... never thought of that bur makes sense to me. I would think its going to be quite tough for someone to tell me what size to go for. I guess Im going to have to go step by step till it runs good... but any advice will help. Im trying to get it running right to sell it. Dont want to stick anyone with crap so I want to iron it out first. I have an 1988 175 in the garage that I will be using. the 225 is wayyyy to heavy for my 20 CC. Thanks again for your time guys

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

an afterthought... so which jet is the low speed circuit? Is it the #14 or the # 20? (lower one or upper one) which ever it is I am going to try a one size lower jet to richen it up.

 

[mikesea]

Re: Evinrude 1986 225 Carb flat spot/stalling

http://12.2.215.22/pub/default.asp?...Lang=EN&brands=SKIDOO,SEADOO,ATV,SPORTBOAT,EJ



hope the link works,in the parts area look for the + - sign to enlarge.its the BRP WEBSITE,CAN GOOGLE BRP,IT THEN ASKS FOR COUNTRY,THEN A PRODUCTS ON TOP WILL HAVE A MENUE FOR PARTS,JUST PLAY AT THE SITE IF LINK DONT WORK THEY GIVE ALL PART NUMBERS AND DIAGRAMS

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

The lower jet is for the low speed.

Are you still running the airbox cover?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

Thanks DHADLEY... the lower would be the #20. I called my local outboard shop, "Outboard Services" in Freeport, NY. Ive been dealing with one of the owners, Mike. I am very comfortable with him so far. He told me they only list 14, 16 and 20's, With such small orifice openings i guess there isnt much choice. I ordered the 16's and will be replacing the lower jet #20 when I get them. Yes I am still running the airbox cover and have reciently replaced the gasket to make sure the air flow is as prescribed. Is there an issue with the airbox cover that you know of? Hopefully the #16 will do it. . They probably wont be in until the end of the week, but as soon as they are in im going to change them out and give it an in water run and report back here to finish the thread

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

Slow down, you're jumping to conclusions. Are you still running the inner air baffle in the cover?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

yes, stock airbox cover with inner baffle... foam gasket that presses against the carbs looks good as well.
What are your thoughts DHADLEY (or anoyon else), you seem to be the go to carb person. I cant think of anything I havent changed that makes sense. Without knowing the history of the motor im not sure what pistons are in there. IF they are .030 over I may have a case for a drop from the #20 jet to a #16. At this point the #16's are on their way to me and im going to give them a shot however I am open to suggestions and dialogue. I have had this motor since sept and have NEVER had this flat spot eliminated despite all that I have done to date.

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

You won't need to rejet even if you bored it out to a 3 liter.

You said in the first post the compression was good so we'll assume nothing has changed there. What spark plugs are you using? Is the fuel (all of it) fresh 87 octane?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

The plugs im using are the requred champions... theres a 77 in there... they came right out of the OMC book at the dealer. Saw it with my own eyes so i know they are correct. As a matter of fact, I had the wrong ones in ther (Qly87 or something like that) and no difference. the fuel is very fresh being its (was) striper season and I was out about 3-5 nights a week trying to reel them in. I use Startron fuel additive (the problem was there before I started using it) and I have a racor water seperator/fuel filter. Keep in mind I idle fine, and my mid and high speed are fine so that rules out alot. if you slowly and consistently up throttle, you would get to about 1/4 throttle, have to hold the choke for a second or two until the motor "woke up" then you can continue throttling to your hearts content. Im just short of putting toothpicks in the #20's and taking it for a spin but the damn 16's should be in already. True, some are saying that even with an over bore that I wouldnt need to jet up, but i dont know what else it could be. We will know soon.

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

Slow down, you're over thinking things.

Are you using 87 octane? Which Champion plugs? QL77JC4?

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

yes, 87 octane, yes QL77JC4

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

OK, good. You mentioned it idles badly. First loosen all the throttle connections. Loosen the one going across the top of the throttle bodies and loosen the one under each middle throttle body. Make sure the roller on the top isn't touching the follower. That will allow all the butterflies to seat. Now start the motor and see if it idles any better. If so, start to tighten each connector. If the butterfly moves as you tighten, you'll hear a change in the motor. You may have to put slight pressure on the butterfly as it's tightened.

If that cures the idle you're done with this part. If not we;ll go to step 2.

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

I like that method iof syncing the carbs while running to see if one "moves" while being tightened. cant hurt, however to be clearer about the idle, it idles fairly smooth but sneezes from time to time and the sneezes go away with a few blips of the choke. I have synced the carbs, but im going to try it with the motor running just to make sure.

 

[Dhadley]

Re: Evinrude 1986 225 Carb flat spot/stalling

While you have the airbox cover off and after you make sure all butterflies are seated, check the reed box gaskets. With the motor off put the motor in gear and wide open. Look in the throat of each carb body. You shouldn't see any reed box gaskets hanging down.

 

[Captain Koz]

Re: Evinrude 1986 225 Carb flat spot/stalling

about 6 weeks ago I removed and inspected the intake manifold. Reeds are all sitting flat as can be with no lift, no gaskets out of place and installed gaskets upon reinstall. Really clean and tight looking. I raced 2 stroke motocross in the late 80's so im familiar with reeds and how they work. Thank you again for youe comments and suggestions... i appreciate them. Keep them coming! Those damn jets should be in tuesday so Im hoping for success on tuesday/wednesday... other wise it will be back to the drawing board. However, I will follow thru on as many suggestions as are given to me. Im looking to solve this asap!