90hp Johnson 1988 v4 (no plane)

[scottygethotty]

Hi

1st post so any help would be appreciated, A bit of a loaded question i know however i will try to provide with as much info a possible.

I have bought a 17 ft bow rider with a 1988 90 hp johnson and its not plaining.

When I bought the boat 1 month ago it had and still has the fins on the lower end of the engine so i'm guessing it had problems planing before.

I took it out today for the 1st time and when throttled up its nose just rises and drags..

Thinking that a 90hp engine should go like stink on a 17ft boat right?

I wanted to know is moving the batteries further forward, changing the prop and getting a stingray help this or is it possible that the boat is just a little too heavy.

Thanks

 

[DJ]

Re: 90hp Johnson 1988 v4 (no plane)

You may have several issues:

1. Hull is dirty and/or waterlogged.

2. "Fin" is holding you back.

3. Engine is not healthy.
-dirty carburetors.
-ignition issues. Use Champion-ONLY!

My bet is on #3.

 

[emdsapmgr]

Re: 90hp Johnson 1988 v4 (no plane)

Also, check the pitch on the prop. A 17 pitch might be a good place to start.

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

eek! well the boat hull is not so much as dirty but its not very smooth it has a repair job under the hull of about 6 inches thats a little bumpy and if you where to run your hand along the hull it would feel a little uneven.


i thought the engine would push through that kind of thing, along with the engine being a little worked on i guess.

 

[Fed]

Re: 90hp Johnson 1988 v4 (no plane)

I've got a 17' glass boat with a 90 HP Evinrude, it leaps onto the plane and tops out at 40 MPH, 5300 RPM with a 17" prop.
My bet is on DJ's #3.

 

[kenmyfam]

Re: 90hp Johnson 1988 v4 (no plane)

Motor needs a basic health check to begin with.
My 2 cents

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

thanks guys i will take a look at the carbs and give them a good old clean out..

Great!

cheers

 

[bktheking]

Re: 90hp Johnson 1988 v4 (no plane)

It's down on cylinders, probably missing spark on one or 2 cylinders, my motor did the same- ground on the powerpack, cleaned reconnected and been fine since. Yours might not be that, could be powerpack, stator trigger, testing is crucial. 40 MPH on my 16.5 but my motor is an 83. I put mine on muffs and felt the heads, one bank was warm the other was ice cold, I knew right away I had no fire.

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

I have checked compression when i bought it, but tomorrow i am going to check the compression again along with feeling the heads to see if their all firing.

basically before I get myself into a carb rebuild I'm going to do another compression test get new plugs and oil and take it from there.

A neighbor said run oil in the fuel alongside with running in the vro system which i did and found the motor to cough. which im guessing now was a bad idea.

I saw this clip on youtube, my outboard runs nowhere near this one even though its exactly the same year and hp.. so im guessing they must go like stink on a boat like mine.

http://www.youtube.com/watch?v=0BGvfYi_obg

Also what grade gas should i use? is it ok to run regular or would premium be better?

 

[SparkieBoat]

Re: 90hp Johnson 1988 v4 (no plane)

if you are going to premix just disconnect the VRO oil line and warning wires. I am a premix guy myself. Also you need to check spark with a spark gap tester, if you are going to be a DIYer then go to local auto parts store and get one. Should be a good strong spark at 7/16 gap. I will almost guarantee carbs need cleaning/rebuild, also check all fuel lines and fuel pump, very common problems there.

 

[SparkieBoat]

Re: 90hp Johnson 1988 v4 (no plane)

dont forget to securely plug the cut oil line going to vro so your fuel pump does not suck air.

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

ok,

before I clean the carb do I need any thing like sprays, seals or gaskets?

ect ect

 

[DJ]

Re: 90hp Johnson 1988 v4 (no plane)

Nope, no sealer on gaskets.

Make sure you get the carb to intake gaskets too.

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

(a carb intake gaskets)?? Is that half a sentence, bad english or what its called?

 

[DJ]

Re: 90hp Johnson 1988 v4 (no plane)

Bad English from working on a Blackberry. A sign of the times.

There are gaskets between the carburetors and the intake manifold. Get those too. Some carb kits have them, some do not. Ask.

The iboats folks are very good at explaining exactly what you will get.

 

[bkwapisz]

Re: 90hp Johnson 1988 v4 (no plane)

I have a 90HP Merc on an old closed bow fiberglass boat and it went like a banshee. Rebuild those carbs and check the ignition: wires, plugs, etc. Should go like heck. Pay careful attention to the cleanliness in the carbs. Any tiny spec of dirt or varnish in them will make it run poorly.

 

[emdsapmgr]

Re: 90hp Johnson 1988 v4 (no plane)

You will need a large can of aerosol carb cleaner to clean out all the passages in the carb bodies. You will need the special tool (or make one) to remove all the carb jets for visual inspection and cleaning prior to reassembly.

 

[fattypackard]

Re: 90hp Johnson 1988 v4 (no plane)

does it idle and run smooth on muffs?

my bet is it is not firing on a cylinder or two also. mine did the same thing.

turned our the two ignition coils were back on top two cylinders.

get a spark tester from the parts store, $5. test spark on all 4 cylinders.
whichever cylinder isnt getting spark....go from there and try and pinpoint the issue.

 

[scottygethotty]

Re: 90hp Johnson 1988 v4 (no plane)

ok got a long list and going to west marine today, thanks for all the help will write back with the outcome and hopefully get a post of the engine working properly.