1988 V135 Reeves timing method vs the Merc book?

[JohnWI]

Is the Reeves method more for OMC rather than Mercs? The book says it will retard at 5000+ by 2*. I'm not about to try testing it on the water at high speed.

I believe Joe's method says to set lower by 4* as they will advance when running faster. Mine calls for: 18* cranking and 16* WOT. Since 18* seems on the lower side, I don't think I'd want to go lower (towards TDC). This engine only has the idle module (not the high speed) which I've currently bypassed.

I thought you guys might know if there's a different way the Mercs and OMCs advance or why the difference in his way vs the Merc book?

 

[racerone]

Timing on these motors generally does not change for the life of the motor.-----What is your motor doing / not doing?

 

[JohnWI]

Timing on these motors generally does not change for the life of the motor.-----What is your motor doing / not doing?

Backstory, it's new to me. First run gave me about 37, then drifted down to 25. I changed a power pack as I I thought one side was cooler. Realized the red wire going to the idle box was missing insulation and likely grounding out. Taped it all up. Ran fast on the muffs so I downed the idle, off to the lake, not any better. Tested the spark lines and replaced the same power pack with the second one (I bought a pair of cheapies) as one line was down. Read too much about the black boxes and disconnected the idle module. Did NOT verify TDC but did the timing screws to spec. 11* idle, 18* cranking. Ran like a champ so I think I'm good but was wondering about the divergent opinions on how they advance when running fast?

One actual issue was it felt a bit rough on the lake in the idle-1200RPM range, or so. I know I set the timing to 11* and also looked at it (on the muffs) and it read 12* so I am thinking of adjusting that a bit to see if it may improve as I honestly want to just putt around the lake more than zipping along. I haven't yet tried to check that timing while in gear on the water which wouldn't frighten me like the top end would.

 

[Dukedog]

throw tha module in tha trash.. make a short white/blk jumper for tha bias post on tha two switch boxes.. forget tha "book" numbers for tha "idle timing"............ put tha rig in tha water, in gear and set rpm/speed to where you and your motor or both happy with... idle timing only................. don't worry 'bout tha number......

i don't know JOE?.. i don't do anything but Mercs'.. Merc's way is best for Merc's.... jmo.

 

[Chris1956]

I would use Merc timing method on Merc's.

Normally that motor would have a 0-9*ATDC at idle pickup, and a 21* BTDC for max spark advance. It can be checked while cranking the engine, spark plugs 2-6 removed. This check is pretty easy....

 

[JohnWI]

I would use Merc timing method on Merc's.

Normally that motor would have a 0-9*ATDC at idle pickup, and a 21* BTDC for max spark advance. It can be checked while cranking the engine, spark plugs 2-6 removed. This check is pretty easy....

That was going to be my next post: The 1988 sticker and service manual state 11* and 18* whereas the 2000 service manual shows your stats of 0-9* and 21*. It does state that it's for 2000 engines and to check your sticker for other models. In addition to that, I believe the models with the timing advance module will also add more degrees on the top end when running close to max throttle.

So any thoughts on what the engineers did with the different model years to have quite a difference in their timing advances?

 

[jimmbo]

There is no such thing as a Idle Timing Spec on these Motors.

 

[Dukedog]

gotta beg ta differ.............. pri. and idle are same thing on these things.................. pri determines idle rpm and speed.. nothing else determines that'' (except idle air jetting).. guess thats why some folkjs (myself included) refer it ta "idle timing"...

most say 0 ta 9 ATDC.. some models say 2 ta 9 ATDC................. hell some even have stickers on tha flywheel cover....... jus don't mean much..

 

[racerone]

There is confusion.----Setting the idle timing on " grandpa's 283 " is not the same.----There idle timing also changes maximum timing advance.----On most outboards the idle timing is the point where throttle plates open.----Actual timing at idle does not matter.-----People start fiddling with outboard timing and guessing.-----Maximum timing advance is usually good for the life of the motor.----Real trouble shooting is often not done.

 

[Dukedog]

there is no confusion at all... they all are set in tha same way, jus different numbers.......... idle/pri has nothing ta do with changing max on tha V6 merc........... there are all kinds of tricks ta do with timing and linkage adjustments.. if ya not completely up on what works and what doesn't its best ta stick with tha manual.. its tha right way for most...................

 

[jimmbo]

gotta beg ta differ.............. pri. and idle are same thing on these things.................. pri determines idle rpm and speed.. nothing else determines that'' (except idle air jetting).. guess thats why some folkjs (myself included) refer it ta "idle timing"...

most say 0 ta 9 ATDC.. some models say 2 ta 9 ATDC................. hell some even have stickers on tha flywheel cover....... jus don't mean much..

You have no clue as to what the Primary Pickup Timing is

 

[Dukedog]

whatever ya think...

 

[jimmbo]

Primary Pickup Timing is the Spec for when the Carbs are about to no longer remain fully Closed. It is not Idle Speed Timing, as the spec is well advanced of what the Timing needs to be to attain Idle Speed

 

[Dukedog]

first i'll agree its not IDLE timing.. at least in any nomenclature.. its something that has worked its way into tha description because of tha results of changin' PRI pick up timing..

tha throttle linkage is what determines when tha butterflies move.. tha timing moves tha instant you move tha timing "ARM".. those adjustments can be varied a lot either way depending on what ya tryin' ta accomplish... most stock set ups will move tha timing arm jus ever so slightly "before" tha throttle plates move........

whatever/however ya wanna define it is jus fine.. but to say primary timing has nothing ta do with idle rpm/speed is ridiculous..... you can't change one without tha other... without "moving a link/sync adjustment" (which ya not supposed ta do after its set) pri is tha only way ya can change it (rpm/speed) on tha v6 merc when all linkages/stops are adjusted right.. other than idle air jetting.... doesn't mater anyway.. if folks jus go by tha manual (except for idle SPEED/RPM desired, sometimes their numbers work and sometimes they don't) they will be jus fine...

jus face it, you don't like tha pharse "IDLE TIMMING" 'cause its not used in any description anywhere 'cept by some of us ya-who's who don't know any better.. i can understand that...........

 

[jimmbo]

If the throttle Plates open too soon, as in not enough Timing Advance, erratic Operation is the result. Most outboards had all the Timing advance in, before there was any real opening of the Throttle Plates, they run fine that why, and it enabled the throttle to be closed once the engine had sped up, but still had all the Spark Advance in place, helping Fuel Economy. Too many people tinker with these engines, not knowing/understanding how they work. I have seen many Linkages tampered with by owners trying to set the Idle Speed on the Carb, and the engine runs like crap after, and no retarding of the Spark will get the correct Idle.

 

[Dukedog]

thats why ya have tha link n sync thats done and locked down.. then ya go to all tha pri(idle)/max timing..
99% of tha guys on here need ta go by tha OEM manual and be done with it....

 

[JohnWI]

I appreciate all the replies as everyone is helping me in my understanding. For ex:
-importance of proper nomenclature.

-That the purpose of the primary screw is to "sync" with the butterflies (this might be why I feel it idles well but in that 1000RPR area it's a bit rough (my fat jiggles). Perhaps I'm slightly too retarded for when the carbs are opening?

-You've confirmed my thought that there's no other way to lower the idle via a carb other than changing jets (which I highly doubt is necessary)- I have the thing set as low as it will go so that primary screw absolutely must do the trick if I need to adjust the idle and pickup timing. Who knows? It might fix my minor issue or perhaps I'll end up splitting the difference between smoothness just above pickup and idle speed? As I said I set it to 11* and when I ran it on the muffs it read 12*. I think I'll try backing it off a bit, closer to 8 or 10* while on the water and see how it responds?

Merc says to use max timing at 18* so I'll stick with that but I'm curious if anyone knows why the later V135s are into the 20s? I'd rather err on the side of caution but fuel economy is always nice, too (I believe being too close to TDC is burning excessive fuel). At least this is one that does not have the high speed timing advance module.

You know, re-reading this is interesting. The manual says do the pickup timing first and then the max timing. Whereas the sticker makes it sound more like set the max timing (probably during cranking) and then get on the water to set the pickup timing because they're mentioning the RPMs during that adjustment.

 

[Dukedog]

you can set either one first at crankin'... first or second.. max should never change after ya "loc" down tha jam nut... tha only things that can change tha max would be a module that hooks up on a switch box.. ie: idle stab or limiter.. (or another electrical part involved with ign) both of which most folks i know trash.. most i know do pri then max at crankin' speed.. (never do max again other than checkin' it when crankin' jus ta be sure) then on tha hose do/check pri.. when its runnin' ta make sure its goin' ta run... then finale pri on tha water... gl with it...

JAN.. we have really never figured out WHY merc will have different numbers for basically same motors other than fuel types, maybe comp but isn't necessary.. all 2.0 135's and 150's have same port timin'/size, same cranks, same pistons/rods, same flywheels but call for different timin' numbers??? same with some of tha bigger horse power motors.. almost every 2.0 since we started with merc in 1976 we set pri where ever it ends up on tha water and then max at 20* with never a problem.. same with tha 2.4's we set max at 22* and 2.5's at 24*.. carb and/or EFI's... this is without any type module on 'em...... go figure??? these were all stock production motors.. our hot rods were a different story though...

 

[Faztbullet]

Set it at 21° while cranking, loosen carb linkages, adjust idle with primary to 1100 rpm on hose, set roller to arm gap at 3/32, check WOT stop and adjust if needed. Good to go

 

[Dukedog]

now thats jus too easy bud!!!

"loosen carb linkages"....

might confuse 'em some?