Timer base linkage

I know it will be hard for a lot of the members on this board to get there minds wrapped around this problem because it should be a plug and play deal. I have a 1983 115hp v4 crossflow eng. I recently replaced the stator and the timer base. The eng was rebuilt just before i bought the boat and there has aways been a problem with idling and low speed operation. I have just recently got the eng running again. I am now trying to get the timing set for idling and wot. With the throttle in the start position I find that the timing is so far retarded that the eng will not start. In order to get the eng started I have to advance the the throttle to about midway to get the eng started. At first I thought it needed more fuel to start but it is really needing to have the timing more advanced in order to start. Here lies my problem. When the throttle arm in the upright position, which I am told is the basic starting position. the timer base is being retarded too far. In order to correct this, I have to screw the idle adjustment screw in all the way. This in turn moves the throttle arm from the upright position and I am back to square one. What I want to do is shorten the rod that connects the throttlearm to the timer base. I have seen older model engs that have adjustable rods for that purpose. What should I do? Thanks for all responses.

These adjustment that you are making do not make any sense at all !!-----------If the motor is not starting properly there is something wrong with the rebuild or other components.-------Report what you find when doing the following tests / inspections.--------Compression test results-------Test for spark jumping an actual gap of 7/16" with all spark plugs installed.----I rebuild these all the time ( doing an 84 -115 HP this winter ) and I usually find that the starter has been damaged by excessive cranking by previous owner.----A slow cranking starter will mean the motor is " hard to start " every time.----Inspect the flywheel key too.--------There should be no need to shorten that linkage whatsoever !!

I don't think I explained what is going on. The eng is not hard to start. It's just that it will not start with the timing retarded as much as it is. The only problem I see is that the top bearing cap seems to be in the wrong position. One of the mounting bolts for the bearing cap can't be screwed in. I think the cap is misaligned. Compression is 125,125,119,123, Spark is fine.

The only thing that can be adjusted on this motor is the maximum timing advance,it should be around 28 degrees BTDC-----------The screw with the rubber bumper !------once that is set you need to adjust where the throttle opens up around 4 degrees BTDC. ---------Then you are done.---------If the engine idles nicely with ignition retarted more than that it is a bonus.---------There should be no need to cut / shorten and metal linkages , none whatsoever.-------The top main bearing cap can only fit one way, I fail to see how one could even assemble that the wrong way.-Sounds like it has a broken screw in there.-------Note -There are 8 screws that go through that upper bearing housing !------If it was in the wrong position you could not install the 7 screws that are in there now.

If you've tinkered with the full spark advance stop screw (screw w/rubber stop cap), set the full spark advance as follows.

(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 temperture. (Your engine does not have this feature, ignore this note)

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, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).

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 (fire) 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 componets, 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.

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

-----------------------

Now...... after you've untied the timer base etc and have the vertical throttle arm fully retarded.... Start the engine and move the throttle (vertical throttle arm) to wherever it has to be in order to start and have the engine running. Now, with the engine running, turn the idle stop screw in to wherever it must be to keep the engine running at a proper rpm.

If a 20" shaft, and running on a flushette, idle at 1000 rpm....... if a 25" shaft, idle at 1200 rpm.

The problem is that your mind is locked in with the thought that the vertical throttle arm must be perfectly vertical in order to start.... which is not so. Many of the models around that year ended up with the idle stop screw (on the vertical arm) screwed all the way in.

A passing thought......I'm assuming that you do have the proper carburetors and high speed/low speed jets installed on that engine?

Ok, Joe I got it. I was concerned about having to screw the idle adjustment screw all the way in in order to get the eng. to idle properly. When I set the idle with the motor on the muffs, It will not ide when boat is in the water. When I set it in the water, it idles to fast on the muffs. It constantly falls dead in the water at idle no matter how I set the idle. Thats why I am playing with the timing at idle. This is a Sea Drive and I have been told that the bypass ports could be causing my problem.

A Sea Drive is simply an outboard engine with a huge transom mount. If you have the engine idling on a flushette as mentioned above..... 20" = 1000 rpm...... 25" = 1200 rpm, when in the water, the exhaust back pressure created within the long exhaust housing should drop the idle to the normal idle rpm.

What I posted above pertains to the full spark advance timing (full throttle).

The idle timing can be set by simply cranking the engine over with the scribe mark on the cam aligned with the center of the throttle cam roller and lengthening or shortening the rod length (threaded nylon connector) until you obtain the mentioned degree setting, what ever the book says, usually something like 3 or 4 degrees. Whatever the book states, that is what it has to be.... you cannot set it to anything else.

If you have the full spark advance set properly and the idle timing set as mentioned here.... and all else is as it should be, the engine has to run. If it does not, a problem lies elsewhere.

Checking spark... Spark plugs removed, The spark must jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! NOTE that checking spark by using the spark plugs is a waste of time. The 7/16" gap is important.

Spark plugs should be Champion QL77JC4 plugs, gapped at either .040 or .030 (original and revised gap setting). I prefer the .040 gap.

Are the carburetors and jets original? You cannot tinker with those, trying to increase horsepower without affecting performance.

Carbs are stock, not sure about the jetting. I think I got what you are talking about the idle timing. By adjusting the nylon connector I would be advancing and retarding the timing for idling. I am recuperating from surgery at this time but I think I will have enough info to fix my problem when the Doc releases me. Thank you for all the help you have given me. PS. When setting the idle timing do I need to make the 4 degrees compensation?

You may be confused by the " idle timing ".---# 1 You set the maximum advance and lock it in place !!!--------# 2-Throttle butterflies must be closed at idle.--# 3-----Idle is then slowed by the timer base rotation further retarding the timing and the further it goes back the better it is ( motor in very good condition ) after the rebuild.---# 4 ----The idle pick-up ( 4 degrees BTDC ) is the point that the throttle plates START TO OPEN UP and it is adjusted with THROTTLE LINKAGES and the engine running and timing light showing the 4 degrees.----------You adjust carburetor linkages for the " idle timing " and not the timing itself.

mo3444 said:

I think I got what you are talking about the idle timing. By adjusting the nylon connector I would be advancing and retarding the timing for idling. PS. When setting the idle timing do I need to make the 4 degrees compensation?

Click to expand...

No.... The engine would be running so all electronic components would be functioning as they should be.

The 4 degree difference only comes into effect when setting the full spark advance timing via the electric starter cranking. However, when you get around to it, if you have time, after you have the idle timing set with the engine running, see what timing degree setting shows up with the cranking method (plugs removed, electric starter cranking engine over). I don't recall if there's a difference there or not and would appreciate having my memory refreshed.

Will do. As soon as Doc releases me.

No hurry, I've been down that surgery route a few times and understand fully. Good luck with your health and a wish for a speedy recovery is aimed your way.