1985 Johnson 90 problems HELP!!!

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

it did not sit that long it was rebuilt maybe 8 months ago and has only sat for a period of maybe 6 weeks without use

 

[rude1]

Re: 1985 Johnson 90 problems HELP!!!

28 degrees is correct actually(27-29) anyway, making any progress?

 

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

Ive made some progress havent figured out the bogging and sputtering yet bet have fixed the other problems for the most part i also found out that after the rebuild the vro was pumping to much oil as was the disconected do you guys think that the motor and carbs could be full of crud due to the exccesive oil before the vro was disconected or could it still be a small leak in the gas line that i have yet to find. I dont get it works great at idle and works great in wot once it revs up and stops bogging.Any other ideas that could cause this. Thanks again for all your help guys this form is great!!!

 

[emdsapmgr]

Re: 1985 Johnson 90 problems HELP!!!

If for some reason, you disconnect the fuel line after running each time to let the engine run out of fuel, the engine will continue to run, pumping raw oil into the carbs-causing a significant oil buildup in the cab bowls. Makes for very hard starting. Not recommended on a VRO engine. Also, if you have any fuel/oil leakage out of the fronts of the carbs (say when you tilt the engine up for trolling) that excess fuel will accumulate at the bottom of the airbox. Each time you start the engine, that excess fuel will get ingested back into the bottom cylinder. It may make starting difficult and will smoke significantly for a few minutes till the engine comsumes that excess. Remove your airbox cover and check your carbs for leakage.

 

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

checked the airbox and the carbs do not leak. Let me recap whats going on. Starting and idle are no longer a problem since i adjusted the idle. The engine was rebuilt about 8 months ago has about 10 hours of run time on it. Shortly after the rebuild we found the VRO was not working right it was dumping way to much oil so we had it disconected and are now running 50:1 premix. The motor runs fine at idle but when you drop the throttle to WOT it starts to bog and sputter for about 10 seconds then revs up to WOT and takes off like a bat out of hell and then runs perfect until you decrease the throttle to much and it starts to losse speed and begins to bog and sputter again. What could be the problem if its not timming or spark. Dose anybody have any recommendation. Could their be a pinhole in a gas line causing air to get in and I just cant find it. I am totaly clueless and have no idea what it could be. Thanks again guys !!!

 

[rude1]

Re: 1985 Johnson 90 problems HELP!!!

I suppose you've done your sync n link, which could cause the same problem. I'm more familiar w/60's than 90's but it should have a mid range jet. Have you checked all your jets which I think is 4 in each carb to make sure they are not clogged?

 

[emdsapmgr]

Re: 1985 Johnson 90 problems HELP!!!

Sounds like a problem with the mid jets. They help with the transition between idle and high speed. Could have a restriction in them or may not be the correct size. When the carbs were overhauled, were the jet sizes compared to the factory parts lists to make sure they are the correct factory size?

 

[Haffiman]

Re: 1985 Johnson 90 problems HELP!!!

You said earlier that you disconnected the vro as it dumped far to much oil!
The VRO can not 'dump too much oil'!!!
It can not deliver more oil than what is needed to mix correct to estimated fuel for each pump stroke.
The VRO most likely did not deliver too much oil, but too little fuel!!
Check your VRO fuel pressure. About 3-4 PSI out from fuel pump.
Most likely time to rebuild the fuel pump side of the VRO, check for air leakages or whatever reduces the amount of fuel delivered pr pump stroke.

 

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

I have no idea if it has the correct jets i did not deal with the mechanic my brother did and he dosent seem to know to much about it either. Would you guys recomend doing a decarb to try to flush the crud out of the carbs if it's there, I dont feel qualified to disassemble them and dont have the cash for someone else to do it for me. Do you guys think that a decarb would help, will it hurt anything if I do it. Thanks again.

 

[NAVY LIFE]

Re: 1985 Johnson 90 problems HELP!!!

You have to pull the carbs and start from there. It is not a hard job just take them apart and clean them. If they were just rebuilt no need for new kits just a good cleaning, link and sink.
go to this link and you will be able to figure it out.
If you are like me and dont have the funds to pay someone to fix it get the OMC book
I picked up one on EBAY for $20.

Go to this link and you will be able to figure it out.

http://forums.iboats.com/showthread.php?t=299680

 

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

I know that there is nothing like taking the carbs off and taking them apart to clean them I was just wondring if using seafoam gas treatment and spraying some deep creep in the carbs will flush some of the crud out if it's clogged. I've read several things on this form about people who had similar problems as my motor and got fantastic results doing a decarb. i do not want to take the carbs off for two reasons. 1: i dont feel qualified to rebuild them and 2: I dont have the money right now for someone to fix them if I screw them up. I plan on getting the boat serviced at the begining of next season and dont want to take my boat off the water with just so little time left before it gose away for the winter. Will doing a decarb harm anything? Dose anyone have any advice.

 

[rude1]

Re: 1985 Johnson 90 problems HELP!!!

Couldn't hurt, just avoid using anything w/ethanol if your already using gas w/ethanol. As you've probably heard 10% ethanol is bad, more is worse, and now the idiots want to increase it more. Some people drain their carbs. during storage, some don't, I do. Top your tank, and put a stabilizer in the gas. Also fog the engine. Find a thread about winterizing. Good luck

 

[BonairII]

Re: 1985 Johnson 90 problems HELP!!!

While doing your decarb, make sure to spray some seafoam directly into the carbs while it's running.

 

[ilboater26]

Re: 1985 Johnson 90 problems HELP!!!

Okay just got back from the river and the boat ran much better still bogs a little though but it is a 100 times better than it was. I did a decarb and it worked much better!!!!!! I took a can a seafoam and put it in about a gallon and a half of premixed gas put it on the muffs ran it for about 15 minutes I sprayed some deep creep into the carbs while it was running. Shut her down let it sit about 15 minutes started the motor ran for another 15 minutes. Then headed out to the river for a WOT spin and right away as soon as we left the ramp she was running much better I ran the tank with the seafoam out and came home I cant belive what this stuff did. I think I will do one more treatment to try to get rid of the rest of the bogging and then she should run perfect. Thanks again guys you have been a big help!!!