1985 Evinrude 150XP Problems

I just recently bought a used boat with a 1985 Evinrude 150XP. The motor runs (With the exception of a miss) pretty good out of water and in. It will go in gear (forward & reverse) good out of water. I took it to the lake today, started fine, had to set the idle a little, put it in gear and it shut off, several times. The only way I could get it to actually run was to lift the motor out of the water, shift into drive then lower it back into the water. It spit and sputtered for awhile then it started to pick up and when it did it ran fine til I would start coming back out of it, the miss started back again and the spitting and sputtering...any ideas what could be causing this? I'm so frustrated right now that I could almost stab holes in it, take it back to the lake and watch it sink Lol.

How long did the motor sit before you bought it? Have you checked the compression on each cylinder? Have you cleaned the carbs? Did you check the lube in the lower unit?

they will actually run very well on just a few cylinders on the hose with no back pressure. the fact that it ran good at speed, and started missing at low rpm is a sign that its likely the low speed jets in at least one of the caburetors being clogged. I wouldnt run it until its looked at, because if your running lean, your running without proper lubrication.

may also want to take a compression test, and get a spark tester and check spark. A compression tester runs about $30, a spark tester about $10.

The guy I bought it from "said" it sit for about a year. I did remove all three carbs and clean them (Maybe not good enough). I will run the two tests suggested ASAP. Will also check the lube. I'm new to boat motors so this is a learning process for me, I just hope it's not an expensive one. Thank you for the responses and I will report back on my findings. Also, I have been told to do a "Link and Sync"...I don't have any idea on how to do one so I'm kinda lost. I'll run the checks suggested here and go from there. I'm not begging but this boat is kind of important to me because it involves my son getting to do something I never did as a kid. He is on a Bass Fishing team at his High School and I really want/need to take him on these tournaments so ANY info that can be given will be greatly appreciated.

Just a guess on the "link and sync" is adjusting the linkage on the carbs to sync them together. Common thing on engines with multiple carbs, like motorcycles and boat motors. Have you changed the spark plugs? Wouldnt hurt if you did.

Steve

New spark plugs. Checked the compression (with an older gauge) and all 6 pushed out a 30, with and without the plugs. Didn't know which way to check them so we did both. My brother noticed that I have a leaking head gasket so that's one thing that will definitely need to be taken care of. Coil packs, 3 where firing, 3 were not but the other day they were all firing.

The fact that you got the matching numbers on the compression test might be good, but hard to tell for sure. You can borrow a compression tester from most auto parts stores.

proper method of testing compression is starting with a fully charged battery. Warm motor up to operating temp. Remove all spark plugs, and set throttle to wide open. do one plug at a time, and crank the same amount for each hole. I prefer to use a gauge that automatically stops when the highest reading is hit and keeps the needle up.

after I do all 6, i then reverse the order just to make sure the battery wasnt cranking a little slower towords the end.

Sounds like you need to be checking the wiring on the motor for shorts and checking and cleaning the connections.

Steve

Bought a spark checker today, all coils are showing a very nice spark...not sure where to go from here.

to test and see if low speed idle jets are clogged, remove cover and intake cover, so you can see into the carbs. make a 50:1 gas and oil mixture and put into a spray bottle. with the engine running on the hose or in a tank, spray the mixture into one carb at a time. if the motor slows or dies off, that carb is working properly. If the engine picks up, that low speed jet is clogged.

Well crap, I should have came here before I ran the tests I did today. I will run the others tomorrow if weather allows. The test I ran today was getting the motor to warm temp, removed all spark plugs (I didn't set the throttle to max...) and checked compression, it came out to be 80 on all 6. I'll recheck again tomorrow with WOT and also run the other tests. I have recently taken the carbs apart and blown them out, every hole I could find. Fresh gas but not the spray bottle test...Tomorrow.

ill have to check my books, but i believe the "stock" compression on those engines is 90 ish pounds. I kknow on my 84 115, the low compression heads allow for a compression of around 100 psi.

the fact they are all even is a good sign, I'd say youre good to go on compression. Move onto the fuel in the spray bottle test.

to clean the low speed jets, I get a 12" piece of wire, and slice it with a knife and get an individual strand of copper and run through the smaller tubes and passages. A good 2 hour soak in carb cleaner, another run with the copper. and a blow out with compressed air and they are generally good to go. if you can take a pic of one of the carbs with the bowl removed look up into the bottom, i'll draw some arrows on where to focus.

also, on the spray test, its best to have a load on the motor to make it easier to tell when the motor picks up. submerging the lower unit in water is generally enough of a load due to the back pressure.

If the weather holds out today I'll get a few pics of the carb. Will tear them down again and go through them with a fine tooth comb this time. I'll have to take the boat to the lake to test it, nothing here to submerge it in...

Here are a few pics of the carb. After taking them apart I ran a small wire thru all of the jets, looked them and noticed "something" inside one of bowls. Blew and used the wire til I didnt see it anymore, not sure if it came out or not, I don't have a screw driver small enough to take the jets out.

I found a kinked hose coming off of the VRO pump. I checked on a few sites and found it, it's called a Pulse Hose. Would this cause the engine to run the way it does? I didn't try to fix it cause I figured I would ask first. Maybe I can find an elbow fitting to go in between the hose...

kinks are never good. the pulse hose sounds like the hose that connects to the motor block and provides the vaccuum for the fuel pump via the piston compression.

id really concentrate on the carbs. the small tubes inside the jets are the areas to clean. soak in carb cleaner a few hours, and hit every nook and cranny with compressed air. the wire will help get the small holes in the jets clean.

I did the carbs today. Ran the wire through every hole I could and then sprayed them out with carb cleaner and compressed air. The miss is still there, I'll take it back to the lake soon to see if it's still doing the same as before.

Here is a way to figure out which ones its missing on. Get a pair of well insulated handled pliers, start the motor, and pull one plug wire off. If it changes the way it runs its firing on that cylinder if it doesnt change the way its running then thats the one thats missing. Check all of them. But be warned it can shock you! I have used this method many times and havent gotten bit much! lol

Steve

As I was looking through the parts list on this motor I noticed something was missing in the carbs. It's the retainer clip that is attached to the needle/float. Is this a needed part or is it ok to run without it?