Sync, link timing on a 1986 90 hp (90AETL Euro)

[kryck]

I have a 1986 90 hp AETL (Euro designation) meaning A engine block, Electric start, Powertrim and Long leg. No autolube/precision blend. 3 cyl 1140 cc, manual and electric choke butterfly, no enrichment valve.

I have found a couple of repair manuals but none of them cover this motor which have the throttle arm connected to a movable magnete pickup. All manuals show the linkage connected to an arm on the CDI.

engine has nice even compression and start easy cold and warm. Seem to run a bit uneven on idle but I guess most two strokes do. Noticeable drop in rpm if any spark plug lead is removed.

Would like to do a proper link, sync and timing but can’t find the specification.

current setting:
wot timing, 22 deg btdc
idle timing, 10 deg atdc
can anyone confirm?

pickup, a hair between the cam and carb roller on idle. Correct or should it be set by timing?

Is there a specification for the magneto link arm length? Or is it not important and max/min timing controlled by the stop screws?

Flywheel pointer still has factory paint on them and is at #1 tdc.

 

[boscoe99]

What is the primary ID of the motor?

 

[kryck]

What is the primary ID of the motor?

Not sure what you mean with primary ID… 1986 90AET(L) as I wrote in my first post. 6H1 is the approval code. 1140 cc 3 cyl without autolube/precision blend.

 

[boscoe99]

6H1 is the first part of the PID. Then an L or and X. Then some numbers.

 

[boscoe99]

Not sure what you mean with primary ID… 1986 90AET(L) as I wrote in my first post. 6H1 is the approval code. 1140 cc 3 cyl without autolube/precision blend.

6H1 is the model prefix.

 

[boscoe99]

I am in the US. We don't have a your model over here. With the PID I can get to the US equivalent.

 

[kryck]

I am in the US. We don't have a your model over here. With the PID I can get to the US equivalent.

It’s 90 AET 6H1 L 350672. No year letter on the euros.

 

[boscoe99]

Looks to be a circa 1986 model year motor. Similar to a US 90ETLJ except that this model has the Precision Blend System whereas yours is premix, according to you.

LIT-18616-00-09 is the Service Manual for the USA model motor if that will help you.

 

[boscoe99]

SM shows -5* ATDC for idle timing and 22* BTDC for WOT timing.

Plus or minus 1*.

 

[kryck]

SM shows -5* ATDC for idle timing and 22* BTDC for WOT timing.

Plus or minus 1*.

Thanks, I’ll check.
1. Is the equivalent US model with moving magneto connected to the throttle arm?
2. Any info on the pickup timing or distance between cam and roller on idle?

 

[99yam40]

I would guess it would be like most others I have seen, close but not touching at idle position.

 

[boscoe99]

Thanks, I’ll check.
1. Is the equivalent US model with moving magneto connected to the throttle arm? I am not familiar with the term moving magneto.
2. Any info on the pickup timing or distance between cam and roller on idle? Yes.

 

[99yam40]

I believe he is talking about throttle linked to the movable stator plate that adjusts the timing on older motors

 

[kryck]

I believe he is talking about throttle linked to the movable stator plate that adjusts the timing on older motors

Yes, my bad. Moving stator is what i mean (although the term is a bit contradicting). The newer motors has a link to the CDI instead. There may be a difference in idle timing between the two CDI types although the engine block is more or less the same.

Anyway, all 90 hp seem to have 22 deg btdc wot timing and that’s the most important.
I have bids between 5 deg atdc and 10 deg atdc for the idle timing. I’ll just check where it idles best in gear in the water.
I’ll keep the pickup at ”just before touching” at idle.

 

[boscoe99]

Is this to what you refer?

 

[kryck]

Y

Is this to what you refer?

Yes, seem to be like this on most carbed two strokes. But I had an Evinrude 70 some years back where there was maybe 5-6 mm gap and the cam should touch the roller at a specific timing value.