I read the link and sync thread and it says 21* max timing but thats
6* less than my manual says and the motor is a dog when set at 21*.
The motor was at 30* before I changed it and has been run this way for >5years. I currently have it set at 25* and it runs ok, just down a little on power. So what is the safe timing on my motor since the link and sync covers all inlines which range from 18*-30* according to my manual? Should I be ok
2* lower than max advance (25* instead of 27*) ?
Just read several pages into the link and sync thread and a couple people
had 850's and were told to run 21* so I guess i'm going to have to run it like that and deal with the major power loss. I guess going down to a 19p prop will be in order.
I run mine at 27.
If your worried about yours or you live where they sell
that oxygenated fuel you could back it down to 25.
The 4 cyl were not prone to burning pistons like the L6 cyl were.
Are you sure that is a 1977? The late 60s mercs used timing specs in the 30s. The 70s mercs used 23* as max timing. Has the timing pointer been verified to be accurate?
Not sure if your asking me or corm. I'm pretty sure it's a 1977, it has
the #4596244 on the mounting bracket and the port side of block. According to my research it's a 1977. Plus it has trigger and coil ignition instead of a
distributor. From what i've read this type ignition was only on 1976 and 1977
model 85hp motors. My cover that goes in front of the carbs says 27* ATDC
max advance @ 5500 rpm as does my manual. Also this is an inline 4. I verified
TDC with a dial indicator and a depth micrometer as well as visually when I
pulled the exhaust cover, the pointer was within 1* Atdc and Tdc.
Not sure if your asking me or corm. I'm pretty sure it's a 1977, it has
the #4596244 on the mounting bracket and the port side of block. According to my research it's a 1977. Plus it has trigger and coil ignition instead of a
distributor. From what i've read this type ignition was only on 1976 and 1977
model 85hp motors. My cover that goes in front of the carbs says 27* ATDC
max advance @ 5500 rpm as does my manual. Also this is an inline 4. I verified
TDC with a dial indicator and a depth micrometer as well as visually when I
pulled the exhaust cover, the pointer was within 1* Atdc and Tdc.
Yes, your motor is a 1977. My engine spec sheet also says to set at 27* BTDC. Personally I would set it at 27*.
I would recommend dropping the timing to 25* and going up one main jet size. The problem isn't the engine but the fuel today. All of the inlines I recommend a 2* drop.
You will run fine at 27* until you get that one batch of junk they call gas today.
Timing is a matter of acceleration more than a power issue. You should not notice any difference between 27 and 25* in power, and on a small acceleration lag but only if you run a very light fast boat.
Inline 6 motors called for 23* most run 21* but even racing I usually took my timing all the way down to 19* at WOT.
Also keep in mind on the ADI ignitions your WOT timing will usually be 2* less than at cranking speed.
__________________
You let the factory smoke out of it. All products have smoke installed in them from the factory. You can not purchase this smoke. The problem is, when you let the smoke out of it, the part is ruined and you have to get a new one. I wish I could find a place that sold the factory smoke.
Never argue with an idiot. They drag you down to their level, then beat you with experience.
3 X APBA Formula V Nat'l Champion
APBA Formula V US-1
It took me 29 years to become an overnight success.
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You let the factory smoke out of it. All products have smoke installed in them from the factory. You can not purchase this smoke. The problem is, when you let the smoke out of it, the part is ruined and you have to get a new one. I wish I could find a place that sold the factory smoke.
Never argue with an idiot. They drag you down to their level, then beat you with experience.
3 X APBA Formula V Nat'l Champion
APBA Formula V US-1
It took me 29 years to become an overnight success.
safe timing on 1977 mercury 850?
Linear Mode
