Timing and Sync of Merc Inlines (to 1988)

[Clams Canino]

Manual specs are different for each but this is close enough to get them all REAL close. This assumes nothing is broken or "wrong" with it. This also assumes that the timing pointer is properly adjusted (if adjustable) to accurately read TDC of the #1 piston.<br /><br />This basic procedure will work for all the 2/3/4/6 cylinder inlines from 1960 to 1988. It's not for the newer 3 and 4 cylinder loopers.<br /><br />Engine off<br /><br />Disconnect throttle cable<br /><br />Pull throttle arm to full throttle and verify carbs open fully. Adjust main throttle stop so that the carbs are JUST hitting thier own little throttle stops. The idea here is that you want the screw stop and NOT the carbs acting as the "final stop" for your throttle lever.<br /><br />Return the throttle to idle, carbs should be closed. Set all idle screws to 1 3/4 turns out from lightly seated.<br /><br />Remove all plugs except #1, hook a timing light to #1. Then follow the narritive.<br /><br />When the throttle is in the idle position the carbs should be fully closed and the ignition retarded. It is the amount of retardation that determines your idle speed and is set later with the idle stop screw. <br /><br />Timing Event One - throttle pickup.<br />As the throttle is advanced, the spark timing advances toward TDC and then to before TDC. As the timing is just passing TDC the 1st (minor)throttle pickup should hit and start to open the carbs. Use the timing light. Adjust the tang or trigger screw to make this a reality. All of them are speced different, but if the 1st pickup hits at 3-4 degrees BTDC advance - you win. Use the timing light with a friend cranking it to complete this setting.<br /><br />Timing Event Two - max advance.<br />As you continue to advance the throttle the timing will advance while the carbs slowly open a bit more. The next adjustment is max advance, this is the point where the distibutor (or trigger) can advance no more. Set the max-advance stop to 21 degrees for "direct charge" crossflow inlines and 34 degrees for the older plain vanilla crossflows. Use the light, - err to the side of caution.<br /><br />Right after max advance, further throttle motion should cause the second throttle pickup to hit and open the carbs to full. You already set that -now verify it.<br /><br />Leave the throttle cable disconnected and go to the water. Leave the boat strapped to the trailer and back it in so it's deep enought to run. Have a friend crank it while you operate the choke and throttle. Warm it up at 1500 rpms's.<br /><br />When "warm" adjust the idle stop screw for about 800 rpm and then ajust your idle needle(s) in (one at a time) till the motor stumbles. Quickly backing it out 1/2 turn from "stumble" will usually save it from needing a re-start. Do that for all the idle screws. Re-set idle stop for 800.<br /><br />Now have your friend put it in gear (make SURE you are on the transom NOT in the water) and reset your idle stop for as low as you can get it. 500-600rpm is great if your old reeds will let it idle that low in gear. Now, re-adjust the idle screws, in to stumble, then 1/2 turn out. When you've gone back and forth with that a few times and have it "perfect" - adjust each one out 1/4 turn.<br /><br />Reset the idle stop so that it's about 700-800 out of gear and 500-600 in gear. Sometimes bad reeds won't let you get that low, you've GOT to get it under 1000 in neutral (worst case) to avoid beating up your lower unit when you shift into gear, even 1000 is "bad" but like I said "worst case".<br /><br />Now adjust (and hook up)the throttle cable so that with the shifter in neutral, there is light to moderate pressure holding the throttle arm against the idle stop.<br /><br />Take the boat off the trailer and go out in the water. Try the hole shot. If it falls on it's face try adjusting the idle screws out 1/4 turn at a time (all of them together) till you can get a hole shot. You can kind of do this on the trailer at the ramp, but it's not really safe for you, the boat, or the tow vehicle.<br /><br />You're done.<br /><br />-W

 

[2cycle]

Re: Timing and Sync of Merc Inlines (to 1988)

Is TDC just as the piston reaches the top (when the dial caliper stops) or is it in the middle of that flat spot before it starts back down? I erred on the side of caution with my timing pointer, so I think I am actually at 19-20 degrees Max Adv. at cranking speed. <br /><br />BTW, as one who has benefitted from Clams' expertise of the inlines and an engine rebuild, I can testify that C.C Marine is a great resource for those of you looking to keep that old inline on the water where it belongs.

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

When it's in the middle. Rock both ways to find it if you don't have an indicator. And err to the side of caution - always.<br /><br />-W

 

[PierBridge]

Re: Timing and Sync of Merc Inlines (to 1988)

I can testify that C.C Marine is a great resource for those of you looking to keep that old inline on the water where it belongs. [/QB]

I did a search for C.C. Marine - Lake Hartwell S.C. the link I found said Look for CC Marine soon to appear on Lake Hartwell.?<br /><br />Thanks Clams....

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

GOOD... that's as it should be as I'm not here to "advertise". <br /><br />Seriously... 90% of what I do is still via Ebay and contacts made via Ebay. Since the move from NH to SC not much of that has changed. I live in a litte town called "Fair Play" and until I got here I never thought *any* town could be smaller than Candia NH. hehe.<br /><br />My marketing stratagy is to get a tri-fold done over the off season, and then pro-actively leaflet all the 60-88 inline 2/3/4/6 on the lake as I come across them. I do have a lighted Mercury sign, but the road I'm on goes to a relatively obscure boat ramp. Being in a "tri-lake" area I figgure once I capture Hartwell, word of mouth will eventually get the other two to at least notice me.<br /><br />And, it's not like I'm really trying to get much busier as my time is equally divided between making money in the shop and then spending the money at home depot to restore / upgrade this huge 3 acre "compound" on the lake. I've learned here that (if you do your own work) it takes at least as long to spend the money at Home Depot (and manipulate the raw materials into a finished product) as it does to make it in the 1st place.<br /> <br />Since this place was abandoned for the year before I bought it, it's been "triage" so far to fix what I had to, and turn a little baitshop/gas station into a little outboard shop. By next season I outta be getting to "optional" projects like restoring the pool cabana that was fire damaged and that I've since gutted down to the studs.<br /><br />So I have two full time jobs.. making it.. and then turning into something to improve the value of my real property. IMHO money has no "real" value till you actually DO something with it, and then hopefully something you want to do to improve your world a little. <br /><br />Unlike boat gas... utility gas spends very slowly. Try buying $20 worth of chain-saw gas and then set out to use it! That same gas that I could go through in a couple hole shots takes about two days of backbreaking work to use properly - and that's saving a gallon or two to start the bonfire to burn all the brush <sigh>.<br /><br />But I ramble.... <br /><br />I hear there's a place on this lake known as "beer can island" or "party island". So if anyone really needs to find me over the weekend it'll be **there**, because I'm gonna find IT and see what's left of a social life on this lake after Labor Day. Just look for the real new runnabout (the kind that should have come with a 2+2) with the real old inline. <br /><br />-W (who will add the number / specs for the later triple and 2+2 to this thread after a weekend of beer and pasta and pizza) <br /><br />PS: See the Red Lobster "endless shrimp" special for a *great* value to enhance your weekend - the 1st plate *before* the refills was well worth the asking price. Please don't ask me how much shrimp/garlic alfredo a human can eat in a night out - I'll never tell.

 

[agrazela]

Re: Timing and Sync of Merc Inlines (to 1988)

Clams,<br /><br />Your method for setting timing and synch for my Mercury 1978 70hp 3-cylinder was far clearer and intuitive than the method described in my SELOC manual. Thank you much.<br /><br />Thanks, 2cycle, for your question regarding where TDC really is...before reading and acting on this thread, my adjustable timing pointer was set to mark TDC as the mid-point in that "flat spot" you speak of. In effect, this caused my timing to be severly retarded...probably on the order of 12-15 degrees. It is no wonder that no other adjustments I was trying would fix my bogging/fouling/excessive fuel usage/hard starting problems. I reset the pointer to JUST where the piston gets to top, followed Clams' procedure, and now my motor has never, ever, started, idled, or run better.<br /><br />iboats is the best.

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

Heh, when I wrote that I had just gotten done going through all that TWICE in a row on 2 different outboards.<br /><br />-W

 

[2cycle]

Re: Timing and Sync of Merc Inlines (to 1988)

agrazela,<br /><br />Glad to hear the question was applicable to your engine and helped out. I went through basically the same thing with mine. I was amazed at how easy the procedure is once one "gets it" and, like you said, the iboating forum and its contributors are a lot more lucid than the manual in most cases.

 

[Bjornis]

Re: Timing and Sync of Merc Inlines (to 1988)

Excellent post!<br /><br />Have the seloc and read the procedure a couples of time and still dont feel that i "got it" (havent tried it yet, just read). When i read this its like "hey is it that simple??"<br /><br />Thanks!!

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

Yes.... it's that simple. Also on some older motors with worn bushings in the throttle/advance linkage it's advisable to insert a couple of little return springs strategically placed so that the advance at idle stop remains the same all the time.<br /><br />John Edwards had a stump speech about "Two Americas". I'm working on one about "Two Idles". hehe<br /><br />-W

 

[stant1man]

Re: Timing and Sync of Merc Inlines (to 1988)

Clams, your experience on this forum is priceless! For someone like myself who has an inline all i need to do is search for posts by "Clams Canino" and I find that any problems I encounter you have solved at least once before.<br /><br />Im sure I speak for many of the forum members!<br /><br />BTW on timing event 2 setting max advance you are having to go WOT, and I presume the engine is running, in gear, at this point are you bombing down the lake hanging onto an outboard with a screwdriver trying to make an adjustment. I just got this crazy picture in my head lol. How is it done?<br /><br />Stan...........

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

You can do it while cranking the motor in the driveway - with all the plugs out or all the carbs empty. Remember at this stage the throttle cable is OFF - YOU run the arm.<br /><br />However, WOT on the lake builds more character, and if you fall off the back, inertia is such that your chances of meeting the prop are minimal.<br /><br />-W

 

[stant1man]

Re: Timing and Sync of Merc Inlines (to 1988)

I noticed an interesting thing today Clams, I disconnected my throttle cable and operated the arm by hand but it did not spring back to the idle position, only the the most advanced stage before the carbs open. Is this normal, whoever had the engine before me apears to have sprayed some thick treacle like greaze over the distributor, it may just be an anti corrosion grease or something but it seems to be creating a smooth resistance in the throttle operation.

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

The throttle will not really spring back alone. This is normal based on all the ones I've seen. <br /><br />There are two grease nipples on the disttributor, grease them and then you can clean the rest of the distributor safely. They prolly havn't been greased in 10 years. <br /><br />-W

 

[Clams Canino]

Re: Timing and Sync of Merc Inlines (to 1988)

Bumping this so that the "spring peepers" can find it easily. I pray to the Cods that JB adds this to the FAQ someday - to save me a lot of typing. <br /><br />-W

 

[lostintexas]

Re: Timing and Sync of Merc Inlines (to 1988)

thanks, i had not read this and i was going to go do a search for any information i could find.

 

[Virago85]

Re: Timing and Sync of Merc Inlines (to 1988)

? I Have a 1977 merc 175 that I have done the whole link and sync thing replaced the tach 3 times with ones and no mater what I do if i retard timing as far as the trigger will move the lowes I can get rpm out of gear is 1000 but if i put it in its still at 1000 then if I bump throttle a little it will go down to 900 any thoughts<br /><br />another thing if i set primary timing with all plugs out put # 1 at 8 degrees then put plug back in crank motor and check idailing its 5 degress take plugs out and check not runing its at 8 put all plugs in but drain fuel and check its at 10 degrease what give I thought if you but it on 8 not runing it would be on 8 runing i have no fast ideal are any thing to unhook on this motor already checked all that but and help would be great <br /><br />if this sounds stupid im sorry ive tried my best to explain all that has been done thinks

 

[sunnygrill]

Re: Timing and Sync of Merc Inlines (to 1988)

Thank you for suggesing this information. I just took out the 3 carbs and fuel pump on a 1977 merc L6 115 hp. I will rebuild them and then I'll follow your instructions to do the timing and synch. <br /><br />I'll have to do more reading but I'm stuck on what do you adjust after you reach tdc and what does the indicator work. You speak of some degrees. I just want to understand and then I'll get it quick. I'll study it more. Thanks.

 

[achris]

Re: Timing and Sync of Merc Inlines (to 1988)

I'd just like to add one thing, with CC's appoval.<br />Make sure the carbs are in perfect synch. ie, they start opening at exactly the same time. If you don't, as the engine comes to the first timing event (the carbs starting to open) it'll run like a hairy goat. <br /><br />Great post CC, well put together and concisely explained.<br /><br />Chris..............

 

[technostingray]

Re: Timing and Sync of Merc Inlines (to 1988)

Where is CC when you really need him? When I saw his name at the top of the post, I thought, Thank the Maker, the force is with us. Now I understand it is the Cods, that bring all things.;D thats a big grin with a wink.<br />For all those interested my main difficulty at the moment is understanding the operation of the cooling function of a 700E direct reversing engine. Childs play by comparison but still a mystery to the uneducated.