'79, 115 Mercury timing pointer??

[pearch fisherman]

motor ran, but was skipping a little.<br />was setting the timing pointer as per manual, .464 mark is out of range of pointer, by 5 or 6 deg.<br />fly wheel cheched out ok.<br />any suggestions.

 

[gungalunge]

Re: '79, 115 Mercury timing pointer??

lake you may of zeroed in on a bad #1 piston or bent connecting rod ..possible mechanical problems on the way . i tested mine .new rebuild . i did not see no degrees of movement,

 

[Chris1956]

Re: '79, 115 Mercury timing pointer??

Lake, the .464 mark is used to set the timing pointer to a known reference point. If you try to set the timing pointer to top dead center, there are a few degrees (BTDC and ATDC) in which the piston is nearly stopped, making it hard to do accurately.<br /><br />A good way to set the .464 mark is: Remove plugs, set top piston to top dead center. Measure from top of piston to edge of spark plug hole with a dial indicator, caliper or thin ruler. Add .464 to this measurement(or zero dial indicator). Rotate flywheel until piston top recedes .464" into cylinder. Now set Timing Pointer to the .464 punch mark on the flywheel.

 

[pearch fisherman]

Re: '79, 115 Mercury timing pointer??

gungalunge & Chris<br />compress. test was 110-114 psi on all clynders.<br />I was using a dial indicator, I just tried it again & at TDC, #1 cyl. the timing pointer is almost right on the .464 mark on the fly wheel.<br />could the marks on the fly wheel be this far off?<br />Thank

 

[pearch fisherman]

Re: '79, 115 Mercury timing pointer??

I just marked the fly wheel with TDC of all 6 cyl.<br />& using a dial with 360o marks, (at 1o each mark)<br />checked the deg. between each cyl. and they where all with in 2 degs. of being equally spaced.<br />any ideas??<br />Thanks

 

[Laddies]

Re: '79, 115 Mercury timing pointer??

Has someone disassembled the flywheel in the past and not index it when they reassembled it, leave it one hole off and causeing the problem

 

[pearch fisherman]

Re: '79, 115 Mercury timing pointer??

when I turn the fly wheel by one bolt paturn, it moves it out of range the other side of the pointer.<br />Would it be possible to change the original fly wheel with an after market, or mabe from an other motor with diffrent marking?<br />just a thought<br />thanks

 

[Clams Canino]

Re: '79, 115 Mercury timing pointer??

Perhaps it was a replacement sticker put on wrong? Just make SURE you *really* have TDC marked right and then set the max advance for a true 21 degrees and forget it.<br /><br />And Gung? A bad piston and/or a bent rod will STILL have it's own personal TDC in the correct spot. Think about it.<br /><br />-W

 

[gungalunge]

Re: '79, 115 Mercury timing pointer??

yea your right the dial indicator would when zeroed will still give you tdc.

 

[gungalunge]

Re: '79, 115 Mercury timing pointer??

lake I took my flywheel off.with out marking it .i had purchased a new engine block then i put the fly wheel from the old engine on the new one .I did the tdc mark thing. using the pointer on the new block. when i assembled my engine i could not figure out why i did not have a timming sticker on the fly wheel and how to set the timming ,then i discovered the timming sticker was on the top of the flywheel cover shroud.and there was a small line etched on the flywheel .then i had to move fly wheel over one bolt counter clock wise. it all worked out after that.the distribitor set in right and the engine fired and i set the timming with a light .

 

[pearch fisherman]

Re: '79, 115 Mercury timing pointer??

Had a couple bad days at work, didn't get a chance to work on motor.<br />I did mark TDC # 1 cyl. and marked fly wheel timing for the primary pick up, & did the same for spark adv., set idle. When for a ride. Motor runs 110% better!<br />Clams Canino, I still have not ruled out bent rod! I try to approach from as many angles as possible to verify, or rule out different diagnosis.<br />Would pulling the head & using a micrometer, to compare with the other cyls. The distance, at TDC.<br />to a straight edge across top of cylinders?, or with the press. test being as it is, all cyl. within 4 PSI be sufficient?<br />Thanks for all the imfo.

 

[Clams Canino]

Re: '79, 115 Mercury timing pointer??

There is no removable cylinder head on those motors. We also ruled out "bent rod" difinitively and for ever about 4 posts ago. If you didn't completely understand the exchange between Gung and I - STOP and take it to the shop.<br /><br />Also .464 could well be outside the pointer range on one side of TDC or the other - it's used as a refernce to help find the true TDC. However the true TDC outta be within the range of your pointer and flywheel sticker.<br /><br />Also the compression test sounds great overall.<br /><br />-W

 

[gungalunge]

Re: '79, 115 Mercury timing pointer??

lake we do this when we suspect a bent rod on any engine.us car mechanics. poke a screwdriver or a suitable measuring device. poke it down into the cylinder .use your thumb nail to see if it comes up to peak tdc .lots of times a hydro lock makes vibration bad in an engine . if we invent it like a spark plug screw it down. tight .rotate the engine and read its tdc on all 6 we would know something about engine diagnosis on bent rods . just an idea . a light spring loaded spark plug fitting with a digital out put that reads peak tdc on each cylinder . it would tell us alot loose bearings or bent rods .here is another to add install a fiber opitic light to read cylinder light time too. all on a set of plug wires .also crank over compression check radar may work too .. see that all in a spark plug