Did I damage my motor by running one carb lean?

[adamh1281]

I have a 1985 Evinrude 50hp. 16ft Key largo center console. I took it out for my first run after buying the boat. I got out of the harbor, pushed the throttle, and planed out slowly, after about 30 seconds it lost power , acted like it was bogging down. I was about 500 yards from the harbor. I removed the plugs to check spark, good spark on top cyl, good spark on bottom, them noticed the bottom plug was dry, and the top was wet. I assumed the bottom carb had fouled in the high speed jet again. I didn't have the tool to remove the silencer, just the cover. It was getting late, and dark, so here's what I did. let me know what yall think.

I removed the primer line from the top carb (wet plug) and put a screw in it. Then ran the motor at about 1k rpm back to the harbor, hitting the primer solenoid (key) about every 5-10 seconds, and alternating with WD-40 into the carb for lube.

the trip back into the harbor lasted about 10 minutes. I will do a compression check this afternoon after work, and look into the plug holes to see if I've scratched the cylinders. What else should I do?

Boat History: got the boat a month ago, put the motor on, removed/cleaned the carbs, but apparently not good enough b/c one clogged before, after the poor cleaning. drained bowl, sprayed carb cleaner into high speed orifice and it ran good on the muffs. Just looking for opinions. Will compression tell me what I want to know?
Thanks
Adam

 

[daselbee]

Re: Did I damage my motor by running one carb lean?

It is beyond me as to why you thought the WD40 was necessary.

If any damage was done, it was because of the WD40.

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

so wd40 was worse to use than nothing at all? seems like some lubrication would be better than little to none. What damage would wd40 cause that would be worse than a scratched cylinder? Or is the wd40 really reducing the lubrication as it is also a solvent? either way I think it is obvious why I did it (says in the post), although possibly not the best choice. thanks for the help.

 

[archcycle]

Re: Did I damage my motor by running one carb lean?

This is what daselbee was getting at:
http://en.wikipedia.org/wiki/WD-40#Formulation

WD-40 does leave a layer of oil behind but it is primarily a solvent. 50% solvent according to wikipedia. The tiny bit of oil in it is intended to displace water attempting to settle on whatever surface it was sprayed on. I don't follow why you removed the line from the top carb? You're much better off filling the cylinder with fuel/oil mix then blowing it out than you are running it with less fuel.

And the compression test is exactly what you need now.

 

[BonairII]

Re: Did I damage my motor by running one carb lean?

If you know what compression was before the WD-40 "thing".... a second compression reading will tell you if you caused any damage.


You really should have paddled(or gotten a tow) back into the harbor.

 

[wilde1j]

Re: Did I damage my motor by running one carb lean?

Running a motor lean for ten minutes isn't going to do much, if the plug was dry. but the motor was likely running lean for quite a while. Do a compression test, then clean/rebuild the carbs. If the middle cylinder is more than 10% lower than the others, you will likely be in for a powerhead rebuild. See info under Top Secret File for carb service. An OEM shop manual may be helpful as well.

 

[BonairII]

Re: Did I damage my motor by running one carb lean?

After thinking about it again....wouldn't the OP have had some 'lean sneezing' on the cylinder that was supposedly starved for gas?

 

[Sprky]

Re: Did I damage my motor by running one carb lean?

Adamh1281 you did a good job of thinking on your feet and getting back.................. Most just go blank.

I doubt that any damage was done as long as you idled all the way back. There is enough lubricity in straight gas to support a motor in a no load situation, you were injecting mixed fuel and an extra lubricant.

The WD40 will not cause any problems. That's just a bunch of BS. Isn't gasoline a solvent?

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

I thought that this may cause some pretty good discussion. Seems like this situation tests some fairly tightly held preconceived notions. the top hose was removed in order to allow the functioning carb to continue functioning without flooding it, and allowing the primer system to dump at least some fuel into the engine for proper lubrication. I thought that would be self explanatory.

 

[daselbee]

Re: Did I damage my motor by running one carb lean?

Ummm....I simply meant that if you were pressing the key in to activate the primer solenoid, which you say you were doing, you were already shooting pre-mix in thru the enriching system. Why dilute it with WD40? You are running pre-mix right? No VRO on that motor...

So why even think you need WD40?

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

good question! as I tried to run at idle, the motor would die because of the on cylinder thing. so I had to give it enough to run at about 1K rpm, which is more fuel than I estimated would come out of the primer system. I would not consider what I saw as I checked the primer system last week as "shooting" more like dripping/draining. I don't even think it is a pressure system, there isn't even a hose clamp on the hose, just shoved on the nipple.

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

wd40 was recommended as starting fluid on 2 strokes before they removed the propane for it's explosiveness.
http://en.wikipedia.org/wiki/Starting_fluid
maybe not so bad?
maybe we'll all learn something at my risk/expense/benefit. I'll post compression results ASAP.

 

[daselbee]

Re: Did I damage my motor by running one carb lean?

Ah well....just don't overthink these things.....

For what it is worth, I don't think any damage was done, WD40 or not. You are probably Ok.

Yes you are right, the primer system is not under any pressure like the fuel system, it is just an elaborate set of hoses to take fuel from the pump output up to the intake when cold starting.

so, if you want to discuss the real issue...non-running, I will be glad to try to help there.

I need to know is this a non-run at idle, or at speed? Does it start and idle fine, then die on take off? When you cleaned the carbs, how thoroughly did you clean? Some guys clean jobs are less than adequate.

Give us a bit more on the non-running symptoms.

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

yea I definitely am overthinking, I've finally got a setup I like, and on the maiden voyage, sat in front of the harbor worried about if I just screwed it all up. I appreciate opinions, and will give info a/b non running. NO I did not do a good enough job at cleaning the carbs. I did not remove the high speed orifice, I just cleaned, scrubbed debris, and shoved a long needle into each side while spraying carb cleaner, cleaned needle valves, reused gaskets, and hoped it would run better (and it did). It was like a 20 min job for both carbs. I just wanted to get the boat into the water and use it. I was planning on buying a carb kit, water pump kit and change both when the season was over (December).

 

[daselbee]

Re: Did I damage my motor by running one carb lean?

Ok, so what is it doing now? No idle, one dead cyl I guess...

When you go back in the carbs, pay special attention to the long brass tube that sticks down into the float bowl. That absolutely has to be clean and clear inside. all the way up into the carb upper body. Clean the very very tiny holes in the sides of the throttle butterfly plate, if you have them. Make sure the floats are set properly, invert the bowl and blow in the inlet, you should get no air flow, bowl right side up, you should get air flow....

Clean the HS jets and passages if you are experiencing poor WOT power and response.

When re-assembling and setting up the linkages, make sure the carb butterflies are closed at idle position. Cannot have them propped open for higher idle...won't work on an OB. All carb butterfiles must open in absolute unison for proper operation.

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

OK 140 psi both cylinders. 20 psi more than when I got the engine. I have a feeling, either i didn't crank the engine enough the first time, or because the motor had been sitting for a long time. taking the carbs down again and removing the high speed orifice and cleaning the skinny tube with a piece of guitar string like I should have before. I'll probably need the rebuild kit b/c the gaskets have probably had it. we'll see if I can get them to seal enough. I haven't messed with the linkages, but will check them to the best of my ability.

 

[daselbee]

Re: Did I damage my motor by running one carb lean?

OK get that done, remember to set floats correctly, and post back the results please.
I use a long set of welding tip cleaner files to get up in that tube. Those in conjunction with some spray carb cleaner. Watch out for aggressive carb cleaners if you have plastic carb bodies.

You have core plugs on those carbs, I hate to say it, but those may need to come out too. The passages behind the plugs are important to get clean.

The problem is the crappy gas we are getting now. Gums up real quick. A healthy outboard is one that is used regularly.

 

[adamh1281]

Re: Did I damage my motor by running one carb lean?

ok, took it out yesterday. ran great. WOT 6K rpm. Idles good. The plugs in carb would not come out. I'll have to drill/pull them out when I get a kit. there is one in the top of the carb right on the opposite side of the high speed jet holes in the throat of carb body. I used violin string from the pickup, and ran it all the way through the system. I have a spray bottle on board now. will run again in a few days. New problem though, I am getting a large amount of spray up the transom, and out the sides of the motor. I think I may be getting some cavitation. I'll post a picture, but I think my motor may be too short. maybe a hydrofoil may help?

 

[wilde1j]

Re: Did I damage my motor by running one carb lean?

Motor may be rigged too deep. Top of AV plate should just be running dry at WOT when height is right.

 

[Sprky]

Re: Did I damage my motor by running one carb lean?

If the motor is running and idling fine, do not remove the welsh plugs. (wasted effort)

Be careful with the welding tip cleaners. You do not want to enlarge any orifice, (especially the idle tube) in the carbs.