timing tool

[moterboat]

where can I purchase the piston stop tool to set timing on 79 rude 140?
and how much are they? went to the iboats marine store and to tools,they are not showing that tool..

 

[iwombat]

Re: timing tool

Just use a bolt and two nuts. Make sure the bolt fits through the plug hole, and the nuts don't. tighten the two nuts together to make the bolt the proper length. Instant depth gauge. Turn the motor over until you feel it hit the bolt. You don't really need an actual "stop".

Enjoy.

 

[moterboat]

Re: timing tool

thats where Im losing it,Im a master auto tech, thats probley why Im not following you, I don't understand how I can adjust the timing pointer to make the mark on the flywheel when the piston is just stopped,how do I determin that the piston is at total TDC by putting a makeshift stop in it?if the purpose of the stop is not turning the wheel to find TDC what is the purpose for the stop??and how do I find TDC to mark the wheel??Im missing something.. is this correct? >> turn flywheel untill TDC is achieved and mark flywheel at pointer?? I did not understand it in the manuel ethier..

 

[iwombat]

Re: timing tool

You set your depth gauge, or stop to a little deeper than TDC. You then turn clockwise until it hits. Make a mark on the flywheel. Now, turn the counterclockwise way until it hits again. Make another mark on the flywheel. Halfway between the two make a third mark. That's your adjusted TDC mark.

Now, set the pointer to the middle. Turn the flywheel clockwise and line up the stamped TDC mark on the flywheel to line up with the pointer. W/O moving the flywheel, loosen the pointer and align it with the adjusted TDC mark (the third mark you made above).


Just for reference, the timing tool is supposed to bottom out at 12-degress BTDC

 

[Dhadley]

Re: timing tool

Since I'm not big on turning a flywheel backwards (water pump blades) we use a motorcycle timing tool. All it is, is a dial indicator thats in an adapter that screws into the spark plug hole. Roll #1 piston up and watch the dial indicator (screwed into #1 spark plug hole). When the needle quits moving, you're at TDC. If needed, move the pointer to line up with 0 on the flywheel grid.

Now, where's that timing light????

 

[iwombat]

Re: timing tool

I've got a similar tool with an air-activated whistle. When it stops whistling you're at TDC. Not quite as accurate as the dial gauge, but for most stock outboards it's good enough.

 

[DHPMARINE]

Re: timing tool

Actually you don't turn the flywheel backwards.You set the stop after TDC and continue turning clock-wise until you hit it again.

The tool is a bit pricey at $51.00,but I've used it for years,and it is well made.Part # 384887 from your BRP Dealer.

DHP

 

[iwombat]

Re: timing tool

If you're going to use the stop, you've got to turn CCW at some point to go back into the ATDC position and bottom out on the stop.

The manuals I have give the directions I stated above. There's even a disclaimer about never turning CCW except for this one procedure.

 

[HighTrim]

Re: timing tool

...and if you dont want to spend the cash on any of the above tools, empty out an old plug fitted with an old welding rod or whatever you have to use as a "stop". Ive always been told to turn the flywheel ccw the second time but I can definately see dhadleys point about the impeller counter turning. I am going to look into getting a motorcycle timing tool. Im not envisioning though dhadley how you get the ATDC point without turning the flywheel ccw after? I also apologize if we're leading this thread astray.

 

[moterboat]

Re: timing tool

Now I understand.. I like the way Dhadley was saying,
doing it with a dial indicator,that I have.. going to try it in a couple of weekends.. Thanks again guys..

 

[Silvertip]

Re: timing tool

Bust the ceramic out of an old spark plug. Tap the hole in the spark plug shell for a bolt. Screw in the bolt. Insert the plug, rotate the engine each time turning down the bolt. When the piston meets the bolt, back the bolt out like a micrometer dial. It takes a delicate touch but the TDC can be felt. It's the point where the piston still touches the bolt but the engine can still turn past the bolt.

 

[levittownnick]

Re: timing tool

I recently did this procedure on my engine, so let me try to explain it.

1) Without any tool in # 1 cyllinder, turn the flywheel clockwise (the normal direction) past TDC (so that now the piston is on the way down) to about 20 degrees ATC (After Top Center). Note exactly which mark you stopped on because you will refer to this number.

2) Install the piston stop and adjust it to touch the piston. (Remember the piston is on the way down).

3) Turn the flywheel clockwise (normal direction) until the piston finishes going all the way down and comes back up and touches the stop that was set up in step 2.

4) Read the number of degreese BTC (Before Top Center). IF the number of degrees before BTC is = to the number of degrees ATC then the timing pointer is correctly set. If they are not equal, adjust the timing pointer so that it is half way between both stops and recheck by repeating this procedure.

Good Luck.

 

[DHPMARINE]

Re: timing tool

Thankyou Lev.

You said it better than me.Maybe somewhere in the procedure you MIGHT have to turn the flywheel backwards a slight bit but I don't see how or why.

The old rule of thumb was NEVER install an impeller with turning the driveshaft counter-clockwise.Great advice.Maybe for a used,set impeller.But when I install a new impeller,with grease or other lubricant,and run the motor,ALL vanes go the same way.No matter how they were when I put the housing down over it.

I have yet to take off a water pump housing and see a impeller vane pointing the wrong way,unless it was really old.

DHP

 

[andy6374]

Re: timing tool

I like lev's method. I bet it's more accurate then finding TDC of the piston and making that mark. Factory Merc manuals (don't know about OMC) always have you set the timing pointer and the piston to a different number other than TDC because there is a certain amount of play (albeit very little) of the piston at TDC, that is at TDC you can turn the flywheel CW with little piston movement or the piston move less per flywheel rotation at TDC than when it is moving up or down the cylinder. So you could be off by (I would think at most) 1-3 degrees by setting the timing mark using TDC.

This could be a merc thing though... i don't know

 

[moterboat]

Re: timing tool

OK, understand how to mark the flywheel now, and I want to back the boat into the water and leave the boat on the trailer and set the timing, what is the cylinder line up? need to find # 1, cannot find in manuel, and set timing at WOT? and at what degrees?? be honest with you,I had the timing and link and sync done by a pro,but I want to recheck it and want to KNOW how to do it, so I can check it at anytime and recheck the shops work, YOU GUYS ARE GREAT... THANKS...

 

[iwombat]

Re: timing tool

If you look close, I'll bet you can see the timing mark from the last L&S. There usually is one if you look hard.

 

[ezeke]

Re: timing tool

edit

 

[moterboat]

Re: timing tool

# 1 is always on top.. is that on the right or left, from standing behind the motor facing it?? 79 rude 140 crossflow.. Thanks..

 

[DHPMARINE]

Re: timing tool

Number one will always be the sparkplug highest and closest to the flywheel. At least for now.

DHP

 

[moterboat]

Re: timing tool

Thanks guys,im sure I'll be back with more questions before Im back to tell you how big the fish was...