Motor bogging down and wont come to full power

[Swampmouse]

I have a 115hp Johnson - 1983 model.

Went fishing today and it ran great for a couple miles. After my second stop it didn't want to start. After a moment I got it started and it idles in neutral, a little rough, but will idle with the throttle up a lttle bit - revs up to high RPM, but when I put it into gear - no power. The motor won't even rev all the way up when in gear - the only way I can describe it is it sounds like it's bogging down. At first I thought I spun a prop, but the motor won't rev al the way up while in gear. Had to idle all the way back to the dock.

Last week I used it for the first time in quite a while and had trouble getting it started. To get it started, I took off the carb. cover to spray in starting fluid. Once running, I didn't put the cover back on for time's sake.

Do you think maybe the carb got a small piece of trash in it that clogged the jets?

Any ideas or suggestions?

Thanks,
Sm

 

[F_R]

Re: Motor bogging down and wont come to full power

One thing for sure is it isn't running on all cylinders. The usual preliminary checks apply. It needs compression, spark and fuel. Check for all three in that order. Yes, could be crud in carburetor. But it can also be as simple as a spark plug. Don't go jumping to conclusions and tearing into something until you have established that is where the trouble lies.

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

Thanks

 

[Solittle]

Re: Motor bogging down and wont come to full power

Troubleshoot first - - fix second.

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

OK - I took it to a local repair place for what I assumed was a clogged carb. I called them back after 4 days and asked what was going on. The guy told me "your motor is blown up" just like that. I asked him what happened and he said that running the enginge with the carb clogged up cracked the rings on 2 pistons. He told me they wanted $2200 to fix it, but they could sell me an older 90hp Johnson for $2000.

I told him to go ahead and clean the carb anyway - he said it would only get worse. I didn't know if he was being honest or not?

Anyway, I brought it home, hooked up the hose and it seemed to idle fine and go fine in gear. I took it to the lake today and it was still "bogging down" - no power.

I brought it home and did a compression test. the top 2 cylinders hit 125 on the gauge and the bottom 2 were less. One was 100 and 1 was 112.

Do these compressions sound in line with his diagnosis? This engine has smoked for the last couple of years, and I know a car's engine will smoke when the rings are gone. I just really do not trust the guy because he was so very non-chalant and he tried to sell me that other engine without missing a beat.

Will I need a new block, do I need to replace the pistons?

I definitely need a new head gasket while I am at it. I suppose I will do it all at one time.

Where should I start with this repair. I am fairly familiar with working on cars but not on outboards. Any advice would be greatly appreciated!

Thanks,
SM

 

[tashasdaddy]

Re: Motor bogging down and wont come to full power

try this before tearing into it. has been known to free up stuck rings, it won't hurt anything, could bring the compression back up.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=36;gtid=1035563


it that doesn't work, you start by getting one of these , either new or on ebay

http://www.kencook.com/evinrudejohnsonmanuals/index.cfm?fuseaction=models.main&year=1983&ID=119541

you are going to have to pull the heads to see the condition, don't break the bolts. could just be gaskets, could be major. don't get the cart before the horse. cylinders can be honed. wait and see whats there before ordering any thing, save shipping.

 

[rickdb1boat]

Re: Motor bogging down and wont come to full power

I would at least pull the heads off before you run it anymore. It may cause further damage that could cost alot more dollars to fix...

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

OK, I decided to go ahead an pull the heads. After I took the boat out on Saturday it is now really leaking a lot of black oil I am assuming from the head gasket - but now like never before.

Tashasdaddy - you suggested some specific manuals. I have a generic type one that covers a lot of models, but does have a section on my model, BUT I do not find it very good. It is made by a company called Intertek.The pictures stink, procedures VERY vague and non-specific. Example: the manual I have just tells to pull the whole power head and says "pull the flywheel, ignition, and charging components IF NECESSARY" - it looks necessary, but I am no expert. There's really no good info about pulling all those components, etc.

Are the manuals you suggested really good and walk me step by step?

Also - the temperature warning switch is what looks to be "epoxied" into the cylinder heads. and has a wire going to one of the wiring harness. How do I remove this? I have disconnected almost all of the electrical harnesses at this point and don't know what to do with this piece - the manual doesn't say.

Also - anybody know what size the nut is that holds on the flywheel? I know It is smaller than a 36mm but larger than a 32mm, and larger than 1 1/4"

Many thanks,
SM

 

[tashasdaddy]

Re: Motor bogging down and wont come to full power

the manual has better trouble shooting guides, as in any manual somethings, are assumed you learn in engine class. which we explain here. it's a far better manual than the intertek, ( i have several for my smaller engine). pulling fly wheel:
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1210765

 

[F_R]

Re: Motor bogging down and wont come to full power

Not sure about that exact model, but the nut is probably 1-5/16". And isn't there a disconnect on the temp wire? Maybe covered by a rubber sleeve? You have to have it disconnected in order to get the water cover off, then the switch just pulls out of the head, with some friction from the rubber.

There is no better manual than the genuine Johnson one. Sold by Ken Cook Co.

 

[F_R]

Re: Motor bogging down and wont come to full power

Adding to what was already said, you can see the condition of the rings and pistons (well most of it anyway) by pulling the four bypass port covers and the exhaust cover. That would be the big pregnant looking thing on the back.

Has the motor ever been overheated or ran in salt water? If overheated, replacement of head gaskets and exhaust cover gaskets is an absolute must-do. If you don't, they will squirt water into the cylinders and cause total destruction of the powerhead.

Don't be confused by what you know about 4-strokes. All two-strokes smoke from the oil which is only used once, then goes through the combustion chambers and most of it is burned, causing smoke. Any that does not get burned in there goes out the exhaust and will be messy if excessive.

 

[ezeke]

Re: Motor bogging down and wont come to full power

The temperature warning switch is held in place by the cylinder head cover, which must be removed to remove the switch.

A few inches down the tan wire is a connector covered by a sleeve. Slide the sleeve down and disconnect,

You will not need to take the cover off the cylinder head unless you want to clean it. If you do, you will need new gaskets for that as well.

BRP parts manual is here:

http://epc.brp.com/default.aspx?brands=ej&lang=e

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

OK - Thanks for all the good info. I did find the connector for the temp waring switch - didn't see it yesterday it was so small- not like the others.

OK - I did a lot of things tonight - I pulled the exhaust cover and both cylinder heads. I will post up some pictures below to show what I found. One thing for sure - the piston on bottom right as facing the bow is missing a ring and it chewed up the piston pretty good and inside of the head a little bit.

One thing I noticed was that inside the left head (as facing bow) was that it was much darker than the inside of the opposite head, which was the one actually missing one of the rings.
[attachment=img=null]

Also on that same side head (left) there was water inside the cylinder/head. It looked like the head gasket had a bad place in the bottom . Is this the reason for darker color? Also, on the bottom of that head, where there is a hole that looks like a weep hole on a water pump on a car motor- where that weep hole is, the metal is actually "bubbled up" or raised and is a shiny metal. But it looks like it was made that way? The other head is perfectly flat at that point, but does also have a hole.

Is this raised part normal?I will try to attach a picture, but it is not very good if I can attach it.It would be the shiny place at the bottom of the picture.

Ok, I am now (I guess) ready to pull the flywheel and charging components underneath and then separate the block from the front half of the crankcase.

1. Can I use a pulley pulley puller to remove the flywheel or should I go with the harmonic balancer puller - either way is fine - I just have a pulley puller at home already.

2. Anything to be on the lookout for when separating the block? (I have to order my new repair manual later tonight or in the morning)

3. Because I will already have everything broken apart, should I go ahead and replace all the rings on all 4 pistons?

4. Because the one piston is chewed up pretty good - I am guessing the inside of the cylinder too - hopefully it is salvagable. Does this mean I will have to bore the cylinder and now use a larger piston? If so, will I have to do this to all cylinders/pistons?

Thanks for all the help! (So far I am actually enjoying this re-build - learning a lot)

SM

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

Obviously I did something wrong with the pictures. I read the FAQ on them, but I never saw a box to check as it states. Anything I should know about how to attach them?

Thanks,
SM

 

[tashasdaddy]

Re: Motor bogging down and wont come to full power

posting pics, copy from photobucket, come to the post, see the yellow box, next to "more" click it, a box will appear in the upper left, backspace the line clear, then paste or ctrl v your html.
if you are talking about a pulley puller with the claws, no, use the harmonic balancer puller... use #8 1/4x20 bolts to go into the flywheel... regular bolts are not hard enough, and will strip off in the flywheel when pulling. i gave you the link above.

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

Pic of what I said about the side of exaust cover on head that had water in it being darker than other side.

[/img]

Also on that same side head (left) there was water inside the cylinder/head. It looked like the head gasket had a bad place in the bottom . Is this the reason for darker color? Also, on the bottom of that head, where there is a hole that looks like a weep hole on a water pump on a car motor- where that weep hole is, the metal is actually "bubbled up" or raised and is a shiny metal. But it looks like it was made that way? The other head is perfectly flat at that point, but does also have a hole.

Is this raised part normal?I will try to attach a picture, but it is not very good if I can attach it.It would be the shiny place at the bottom of the picture.
Pic of what I said last week -- Is this normal - the raised part? How about the weep hole?

[/img]

Pic of lower unit with oil leaking down - presumably from bad head gasket or exhaust cover gasket - I think exhaust.

[/img]

SM

 

[tashasdaddy]

Re: Motor bogging down and wont come to full power

i learn something i didn't know about photobucket. clik the little box under the pictures you want, then go the bottom of the page, clik, generate html, a page will come up with selections, copy the one, that says thumbnails for message boards . then in you post, you just simply paste them to the post. they will appear after you end the post. so much easier,

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

thumbnail test

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

AH HAA! Success! Thanks Tashasdad!

The test picture showed both sides of the exhaust cover - see text 2 posts up.

Head pic with "bubbled" metal at bottom with weep hole


Lower unit descrided above

 

[Swampmouse]

Re: Motor bogging down and wont come to full power

I am actually much farther along now but still want to know the answers to the above questions.

However, the following is a pic of the inside of the front half of the crank case - look closely and you will see a little burr off of one of the "grooves" the cam rides in. Is this really bad? I know obviously it is not good. It is Less than 1/8" thick X 1/4" long of a burr that is almost completely "chipped" away. Will I have to replace the crankcase??


Also - very important. What kind of socket do I remove the screws that hold the rod caps?



Thanks,
SM