Logo
FULL SITE MENU

1988 90 hp Evinrude ignition timing

A

ajsupra

Member
Hello everyone, first post here... Long time lurker. Please be gentle ;)

I have an 88 90hp VRO that is bogging under load. While going through the regular diagnosis steps, I noticed that the timing advance lever sits about 1/2 to 3/4 or an inch from the stop at WOT.

This engine is new to me, ran great once and has been plagued with high load running problems ever since. I don't remember ever touching the high speed advance screw, but anything can happen.

I've searched high and low for the timing spec for this motor but can't find it. I don't have a repair manual yet, tho that looks to be a good idea with these motors.

I was hoping to use the reeves method to see how close/far the timing is to spec before I go any further into diagnosis and spending $$ on carb kits, cools etc.

Can anyone help me out with a spec for ignition timing at WOT so I can guestimate where I'm at?

A little bit of extra info is required as well... This motor started running like poo after a very bad tank of fuel was used by mistake. The carbs have been cleaned (not perfectly, just a quick job... I know, I know), plugs changed (with ngks and champs), fuel pump was changed in order to a unit from an 88spl so I could ditch the vro and the lines and fuel filters were replaced just as maintenance.

Hitting the choke smarten things up a bit, but the lack or power is still present.

So, as I mentioned...I don't think timing is going to be causing my issues... I'm more interested in checking for the sake of being thourogh.

Thanks so much,

-Aaron
 
ajsupra said:
I have an 88 90hp VRO that is bogging under load.

1 - I noticed that the timing advance lever sits about 1/2 to 3/4 or an inch from the stop at WOT.

2 - The carbs have been cleaned (not perfectly, just a quick job.

3 - plugs changed (with ngks and champs) Aaron
Click to expand...

Start with a compression test (all spark plugs removed)... What is the psi of all cylinders?

Check the spark (plugs still removed)... The spark should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it? The gap is important... checking by using the s/plugs is a waste of time! You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark

1 - If you're speaking of the rotating timer base under the flywheel not contacting a rubber stop on the head of the spark advance screw, and that screw hasn't been tampered with..... that would indicate a sticking timer base that would keep the spark retarded. If this is the case, that sticking must be corrected... normally caused by one of the four retaining clamps being too tight... OR... a failing stator starting to melt down and dripping a sticky looking substance on the timer base and powerhead.

2 - There are four (4) high speed jets, located in the bottom center of the float chambers, way behind the float chamber drain screw plugs (one on each side of the carburetors). They require cleaning (carefully) with a piece of single strand steel wire as solvent just doesn't do that job properly.

3 - Spark plugs should be Champion QL77JC4 plugs gaped at either .040 (strong spark) or .030 (Long life).

Let us know what you find.
 
Start with a compression test (all spark plugs removed)... What is the psi of all cylinders?

Check the spark (plugs still removed)... The spark should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it?

1 - If you're speaking of the rotating timer base under the flywheel

2 - There are four (4) high speed jets

3 - Spark plugs should be Champion QL77JC4 plugs gaped at either .040 (strong spark) or .030 (Long life).

Let us know what you find.
Click to expand...

-Joe, thanks so much for your help. Compression test is job number one for me today... I have my gauge at the lake now so we will see where it stands.

-The spark easily jumps a 7/16 gap. However, I wouldn't say that any of the coils produce a SNAP... But the spark is a bluish white color. Speaking of spark plugs, the bottom two plugs are definitely burning differently than the top... Cleaner I'd say. The porcelain is cleaner than the top plug

-The timer base (thanks for the clarification) is exactly what I'm talking about. I don't believe it's sticky though as I can disconnect the linkage from the lever and easily move it to the end stop. It moves very easily through the whole range of motion. As the throttle cam moves to wot, the timing advance lever runs out of travel and will not pull the timer base any further towards the end stop (max advance)

Adjustable?

-high speed jets are today's other job. I have the carbs off and am going to be getting them clinically clean this afternoon.

-I had the champion plugs at 030 in the motor when it first started to act up and ngks at 030 or 040 didn't help. The champs went back in and have not been adjusted to 040 yet.

Thanks for your earlier detailed response and the help, its really appreciated.

Cheers

-Aaron
 
Last edited:
In thinking back.... that 1988 90hp model does not have the spark advance stop that incorporates the long screw with a lock-nut and a rubber cap on the head end.... and for the life of me, I can't remember if there is a spark advance stop at all... OR... if it's built into that slotted throttle arrangement (mental block?).

However, I would suggest you check the full spark advance timing for peace of mind if for nothing else. It can be done as follows on your engine... no need to have the engine running.

(Timing At Cranking Speed 4°)
(J. Reeves)


NOTE: If your engine has the "Fast Start" feature", you must disconnect/eliminate that feature in order to use the following method. The "Fast Start" automatically advances the spark electronically when the engine first starts, dropping it to normal when the engine reaches a certain temperature.

The full spark advance can be adjusted at cranking speed,"without" have the engine running as follows.


To set the timing on that engine, have the s/plugs out, and have the throttle at full.


Rig up a spark tester on the #1 cylinder plug wire. Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4° less than what the engine calls for.


It's a good idea to ground the other plug wires to avoid sparks that could ignite fuel that may shoot out of the plug holes. I've personally never grounded them out and have never encountered a problem but it could happen.


I don't know the full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28°, set the timing at 24°. The reasoning for the 4° difference is that when the engine is actually running, due to the nature of the solid state ignition components, the engine gains the extra 4°.


If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4° which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place.


No need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting.

A fellow member from one of the various marine forums suggested having water supplied to the water pump (flushette or barrel) simply to provide lubrication to impeller. A worthwhile suggestion I thought, and entered here.


Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
Thanks Joe, I'll get a picture for you later this afternoon of the arrangement, just in case.

As far as the timing, do you happen to have a spec for the motor that I can use as a starting point? I understand the -4degrees thinking and it makes good good sense to me.

However, without knowing the base number I'm still kinda stuck. I have omc 3 cylinder books here at the cabin but no v4 book... Yet.

Any idea?
Thanks again

-Aaron
 
Sorry... Trying to get images to upload via mobile apparently doesn't work. Will try finding a laptop.

I checked the timing base and it's adjustable via a cam on the throttle lever. A flat head screw can be loosened and the cam turns to advance or retard the timing. I played with it but ended up putting it back to where it was, simply because I don't believe it was ever touched.

Havn't Done a compression test yet as I had the carbs apart last night soaking in carb cleaner. When I pulled all the jets I found one plugged up high speed on the lower carb and one plugged up low speed on the upper carb.

Adjusted the floats, cleaned the rest of the pieces up nice a proper and reassembled the engine for now.

Will check compression this afternoon when I have a second set of hands.

Thanks again
 
Last edited:
Sorry, I don't have the manual handy for the 1988 90hp. Hopefully some other member will jump in here with that full spark advance figure.
 
Just an update on this motor, I pulled the carbs apart AGAIN and found some gunk in the high speed jets. Don't know how I missed it before, but it runs beautifully now.

Thanks for the help everyone!

Cheers

-Aaron
 
ajsupra said:
Just an update on this motor, I pulled the carbs apart AGAIN and found some gunk in the high speed jets. Don't know how I missed it before, but it runs beautifully now. Cheers, -Aaron
Click to expand...

Yeah, that can happen in a "quick" carburetor cleaning job, hence my 1st reply, post 2. Those high speed jets clog up fairly easily.
 
joereeves said:
Yeah, that can happen in a "quick" carburetor cleaning job, hence my 1st reply, post 2. Those high speed jets clog up fairly easily.
Click to expand...

Joe, I appreciate your help. Right on the money. I had actually cleaned them out the same day but wasn't able to get it on the water until this weekend.

Also made a point today of putting a new omc fuel filter in the motor to help prevent this from occurring again.

Sometimes we forget about the simple things and bypass the basics just thinking they must be ok.

Cheers,
 
Re: 1988 90 hp Evinrude warm start

I have a 1988 Evinrude 90hp V4 VRO. It runs very strong. Had the engine compression checked, new power packs. On cold starts no problem. But after fishing for a while it will crank strong but not start. My brother took cover off and opened the chokes which are connected by a linkage and it fired right up. This happened several times. Am I doing something wrong in the start up sequence? Should something be opening the chokes. I do appreciate your help and advice. ALP
 
There are no " choke plates " on this motor.---Throttle plates there are.----Try advancing throttle with control box.----Try pushing in the key while cranking it over.
 
APJP------Pushing in on the key opens an electric valve.---When cranking this puts fuel directly into the intake manifold.-----Replaces choke shutters.-----Must be used when motor is first started for the day.------What other trouble shooting has been done on your motor if any.-----Compression test numbers are ?
 
Back
Top