1989 48 HP Johnson Outboard No WOT With Air Silencer On?

[Highdog1]

Thanks oldboat1 , will do.

 

[Highdog1]

oldboat1 - I did as you suggested and got the laquered thinner and soaked both carbs, cleaned with wire and air & got it back together and both cylinders passed the drop test! It does have a bit of a backfire, but starts good and idling. Does this sound like one could be too lean now? Haven't had chance to get it on the water and test it out again on the bogging problem. Thanks a bunch for all the help you given!

 

[oldboat1]

Hey! Sounds like progress, Highdog. It does sound offhand like it might be a tad lean. Hope the water test goes well with the bogging. When out there, tweak the air mix a little and see if you can dial out the backfire.

Hope you post back results. Always like success stories (pressure is on....)

 

[juno pierrat]

quick check to see if both carbs are fully closed at idle is to remove linkage between carbs, i had a bad lean sneeze, thought thing were adjusted correctly, but no, when linkage removed got perfect idle instantly.

 

[Highdog1]

Thanks oldboat1 - I surely will!

 

[Highdog1]

juno pierrat - I will double check on that. Thanks for the help and input.

 

[juno pierrat]

bump, any updates?

 

[Highdog1]

oldboat1 - The pressure was on LOL... Finally got her on the water and tweaked those carbs , but still bogs with the silencer on. If I take it off and leave the cowl on, it goes without a hiccup. Starting and idling good, and I backed out the top carb some and the backfire was little better. But now, I also noticed this after bringing it in and left it on driveway where on the cement under the prop there is definitely lower gear case oil? It's dripping out of the prop. Not a lot, but enough. I checked the gear case oil and there did appear to be some water in there. I'm guessing I got a bad seal in there? gonna have to check that out. Is it possible this could effect the back pressure or vacuum , or am I looking at probably a whole different problem going on here? Also, on the carbs - I did check that linkage and carbs are fully closed in neutral, opened as should be on wide full throttle. I'm pretty sure those carbs are ok and better now. Any other ideas what could be going on here?
Thanks for all the posts and help here.

 

[Highdog1]

Also, I pulled the flywheel off to have a look see underneath , and all is dry and no leaking at all. Looked good.
Thanks

 

[oldboat1]

prop seal maybe, if it's gear oil and not exhaust water and fuel (smell test). I'm inclined to think it's fuel related to carb adjustments. If it's gear oil, it's a separate problem, seems to me -- unless the backfire turns out to be a gear case issue (typically a clutch dog problem). Has sounded like ignition or fuel issue, from your descriptions.

Running difficulties with the silence cover is still a mystery. Seems to cut air flow. Still wonder if venting the cover would be a fix.

 

[Fed]

Crankshaft seals?

 

[Highdog1]

oldboat1 - yeah it's definitely gear oil. That stuff have such a distinct smell, and it drips out the prop. Gonna check that seal out. The clutch dog I think is ok, it doesn't grind at all , gears seems to shift ok. I posted a pic above of the side of the engine where just behind the primer solenoid and above the linkage , there was some gas and oil residue on the bolts and case. It's not a lot but before I took it out on the water last time , I cleaned and dried it off. Re torqued those bolts( so I thought) and I noticed there was some gas/oil in that spot again. I'm thinking when it's under load in the water is when its doing it. The primer solenoid is dry as a bone so no leak/splatter from there. On just the muffs I don't see anything coming out of that area and took a spray bottle with some detergent soap and water to see if I could notice an air leak there. But there wasn't any. May just be when under load and pressure, it doing it. I really cannot figure where gas could be coming from in that location. It's not dripping from the flywheel. It;s not over heated or anything, but when I rebuilt the motor a couple of years ago, maybe i didn't seal it all that good? Not even sure if that's a problem here but it does seem abnormal gas/oil is collecting there. Might explain some air loss , gas oil loss. Thought id clean it up again real good, put some paper towels around that spot and take it on the water, see if it collects there again. And like you said, I do believe prop is a separate issue.
Thanks

 

[Highdog1]

Fed - I have thought of that. Thinking I'm gonna have to have to do some tearing down. But I do got a feeling it's in that manifold area. Dread tearing apart again lol , but at this point looks like I may have to. Not had any damage there but as I explained above maybe when I put the case and block back I didn't seal it good enough?> That was a couple of years ago, but I used what was recommended and basically a lock tite stuff. There's no gasket for that area, I really am at a loss. Or crankshaft seal as you said, but would a bad crankshaft seal cause it to come out the case in that area? I've thought of replacing bolts and re torquing those bolts, take it out and put something there to really confirm it's coming out of the case there.
Thanks

 

[Highdog1]

Under the flywheel looks really good. No leaks.

 

[Highdog1]

P.S. Gonna recheck those primer solenoid hoses to make sure no leak or spray could be coming from there. It may be from hoses? but the solenoid itself and red know are totally dry.

 

[Fed]

Highdog I was thinking more along the lines of it drawing extra air through the seals when the restrictive air box cover was fitted causing a weakened air/fuel mix in the crankcase.
Possibly fuel/oil leakage may be a value added symptom I hadn't thought about, my head has been stuck around the air box cover.

 

[juno pierrat]

is there excessive wear on the shaft and bushings that goes thru the carb body that the throttle plate is attached to?

 

[Highdog1]

Fed - I replaced the gaskets around the carbs and the air box, also the reed valve box gasket. The air box and cover on there now are the original ones I got with the boat and has worked fine in the past. That fuel / oil mix has me totally baffled as well. On just the muffs it doesn't appear to be anything coming from there, bring it in from the water and I see it back in the same spot. I figured on the muffs it may not be producing enough pressure to see it if it's blowing out there? Or where it could be blowing from. Seems like if it was blowing out from behind the air box / carbs all the other stuff would have some residue too, but it doesn't. i
​Thanks

 

[Highdog1]

juno pierrat - I hadn't checked that, how would I know if it's bad ? Those seem pretty fixed in there. I did notice there is one of the screw heads has fell off the back of it. but the screw is still fitted in there. They open and close ok. Ill for sure double check on that.
Thanks

 

[Highdog1]

When I replaced the reed valve gasket , they look great too. No issues going on in there.