Mercury 115 timimg pointer seting

[Gmcviper]

Here is how I did it. I think its wrong. With a dial indicator in#1 turning engine clock ways (running direction) till it peaks then zero the indicator go around again till zero then loosened pointer and set it to zero. Then to set full advance timing running the boat on the lake with timing light on motor made sure the distributor was against stop them I adjusted screw till it was at 19° to be on the safe side it was at about 25°. Now it is gutless and barely planes out.

Here is the way I believe to be correct to set pointer. Turning engine counter clock ways (opposite of running direction) have indicator in#1 when the indicator peaks zero it out then continue to turn it counter clock till indicator reads.464 then set pointer to zero.

are either of my methods right?
Thanks for the help

[Glasstream15]

From the factory manual <!--[if !supportLists]--> 1. <!--[endif]-->Remove all spark plugs and install dial indicator into No. 1cylinder.
<!--[if !supportLists]-->2. <!--[endif]-->Turn flywheel clockwise until No. 1 piston is at Top Dead Center (TDC). Set dial indicator at "0" (zero) and tighten indicator set screw.
<!--[if !supportLists]-->3. <!--[endif]-->Turn flywheel counter-clockwise until dial indicator needle is approximately 1/4 turn beyond .464"(12mm), then turn flywheel clockwise so that dial indicator reads .464" exactly.
<!--[if !supportLists]-->4. <!--[endif]-->Reposition timing pointer (if necessary) so that timing pointer is aligned with .464" mark on timing decal. Retighten pointer adjusting screw.
5. Remove Dial Indicator from cylinder and reinstall spark plugs and spark plug leads For some reason, I am having a lot of trouble with formatting this reply. I hope it helps anyway.

[Gmcviper]

280255280256
The position the #1piston is at .464 so I am thinking moo flywheel is indexed 1 bolt hole advanced. Would that mean my distributor is off too?

[milkdud]

The .464 number I believe is an arbitrary number. All it does is make you reverse rotate the rotating assembly to take out any movement from bearings pins etc... You can for a practical short cut forget about the .464 setting for now.

I can find TDC on #1 with a ball point pen within a degree or so by sticking it in the cyl and rocking #1 back in forth. Im not sure why your having issues finding TDC?

A very simple way to find perfect TDC is to put something in your spark plug hole that interferes with the piston. (I use and old spark plug with porcelain broken out with a set screw holding a 3/8 brass rod. )

Rotate clockwise until it hits mark your flywheel. Now turn Cournter clockwise till it hits mark your flywheel again. The exact center of those two marks is TDC. This takes all the slop out of the rotating assembly. If you adjust your rod in or out perfect your two lines will be very close together.

once TDC is found move on Like I said I can feel out TDC with a dowl or pen in the hole and get pretty damn close in 5 seconds.

Then crank the motor over with spark plugs out and grounded. Put your timng light on #1 and set to 19 or 21 whatever you feel comfy with. If you have a timing light like mine you can set the advance and shoot off the 0 mark.

Never heard back from your first transmission.
Conrad

[JWTjr.]

Conrad's method is the way OMC has advocated doing it for decades. It is dead-on balls accurate (that's an industry term ;).

[Gmcviper]

Ok I miss understood the procedure I thought it wanted you to put the pointer on 0° when it was.464. My sticker is crappy So it's hard to see. Well im right on then and the arrow on distributor pulley is aiming at the 3 dots on fly wheel. So everything is right there my timing method has to be the problem. How should I be seting the full advance timing?

[Gmcviper]

I set my throttle to wide open throttle pulled the number one spark plug out rotated the engine till I could hear the spark it was at 20° did the same at idle it was 10° before top dead center is that normal? Now I have 7.5 hours on motor and ran it up to wot it would only spin 4500 rpm what could be wrong? Not too much prop 22 pitch on a viper.

[milkdud]

I cannot remember. Let us know what you did to this thing? Is this the viper that was wayy over timed and was burning pistons?

Why were you timing it again? What did you adjust, take off etc?
Conrad

[Gmcviper]

Yeah same one it fried #3 took motor down to the block honed it and put a used piston in and new rings. I also cleaned all carbon from exhaust side. all new gaskets and seals. Could it be my initial timing is so late by the time it gets advanced it has to much fuel? Could a bad cdi cause the rpm to plateau before red line?

[Gmcviper]

I screwed up earlier idle timing is actually 10°after tdc. And when I first got the boat the max advance jamb nut was loose so that's the original reason I was questioning the timing.

[milkdud]

I never check my idle timing. it usually is what it is after I set it up. THe WOT timing is key and it sounds like yo have it right.

Are you butterflies coming all the way open? Look at your plugs are they all the same or are some dry some wet? Sounds like your timing is right but you may have something else wrong after you took it all apart. Start looking around.

Is the compression good?

Conrad

[Gmcviper]

Carbs are opening all the way. I have 120psi cold on all 6. Plugs all are slightly wet. I checked pickup timing as shown in a video on youtube by the "link and sync" method and it seems right. I did notice the first stage that opens carbs only opens them barely and then the distributor rotates to full advance befor the second stage moves the carbs. That doesn't seem right I would think timing would aadvance as the carbs are opening.

[Gmcviper]

280358

[milkdud]

plugs look normal. The motor runs on advance and accelerates on advance for quite a while before the carbs open up.

conrad

[Gmcviper]

Would corrosion on the wheel in the distributor make a difference? Is there any checks i could do on the cdi box that would indicate if it's ok? Can I check the reed valves they looked like they were closed all the way when I had it apart. I went to the dealer today and ordered a manual. Thanks for all of your help!