742B Timing issues

[brdgbldr]

After replacing the points, and properly gapping them, on my 742B the timing was so bad that I had to guess how far to move the distributor just to get it to start. The problem is that there is not a "notch" in the camshaft pulley to use with a timing light. At first I saw a punch mark in the pulley and figured that was it but then I found a silver sharpie line that seems to be what was used by whoever timed it last. So is the punch I found supposed to be the timing mark and the pully is installed 90 degrees off? Is it possible to time an engine without a timing mark? And even if the punch is the timing mark, is there any way of figuring out where the mark should be without having to fix the pully? Is the timing mark supposed to be at zero degrees when the number one piston is at top dead center? I have the machine running pretty well with timing it to the sharpie line I found but I don't like guessing with the timing. Thanks

 

[antfarmer2]

Could the distributer be put in wrong?

 

[wbecker319]

Antfarmer2 I think has it right, the distributor is 180 deg. off. You could pull it out and see if it will go in 180 deg. Or if you have the specs from the engine manual for the timing, you could put #1 piston at TDC compression stroke, and use a protractor or degree wheel to make a mark at the place on the pulley that is the correct advance. (I'm thinking you meant crankshaft pulley, not camshaft).

 

[brdgbldr]

Antfarmer2 I think has it right, the distributor is 180 deg. off. You could pull it out and see if it will go in 180 deg. Or if you have the specs from the engine manual for the timing, you could put #1 piston at TDC compression stroke, and use a protractor or degree wheel to make a mark at the place on the pulley that is the correct advance. (I'm thinking you meant crankshaft pulley, not camshaft).

Yes, I meant crankshaft pully. I do no believe that the distributer is out 180. I know a guy that did that once and it caused the engine to fire with the exhaust valves open which caused the exhaust manifold to glow red. The engine runs fine the way it is I'm just not totally sure the timing is spot on. It appears that the engine was rebuilt in 98. It actually has a metal tag on the engine cover saying "Remanufactured for Hyster". Of course who knows who had it since? I do believe in "if it ain't broke don't fix it". I bought this at an auction. It wasn't running so I got it for cheap and the only thing I had to do to it to get it running was replace the broken coil resistor. I drove it off the auction lot and onto a trailer! It ran fine for over a year and then it stated to get hard to start until it wouldn't start at all. So I did the usual and started a tune up. New plugs (old ones over gapped but looked ok), new cap, rotor and condenser (I got the condenser with the tune up kit from Bobcat and the wire on it is an inch too short, not what I expected from Bobcat), new points (the points were also over gapped and fried, thus the no starting). I could see getting the pully on wrong, but the punch in it is directly over one of the four pully bolts and the Sharpie line is not, meaning that the two are not quite 90 off of one another. I appreciate any thoughts on this, thanks.

 

[wbecker319]

Yes, I meant crankshaft pully. I do no believe that the distributer is out 180. I know a guy that did that once and it caused the engine to fire with the exhaust valves open which caused the exhaust manifold to glow red. The engine runs fine the way it is I'm just not totally sure the timing is spot on. It appears that the engine was rebuilt in 98. It actually has a metal tag on the engine cover saying "Remanufactured for Hyster". Of course who knows who had it since? I do believe in "if it ain't broke don't fix it". I bought this at an auction. It wasn't running so I got it for cheap and the only thing I had to do to it to get it running was replace the broken coil resistor. I drove it off the auction lot and onto a trailer! It ran fine for over a year and then it stated to get hard to start until it wouldn't start at all. So I did the usual and started a tune up. New plugs (old ones over gapped but looked ok), new cap, rotor and condenser (I got the condenser with the tune up kit from Bobcat and the wire on it is an inch too short, not what I expected from Bobcat), new points (the points were also over gapped and fried, thus the no starting). I could see getting the pully on wrong, but the punch in it is directly over one of the four pully bolts and the Sharpie line is not, meaning that the two are not quite 90 off of one another. I appreciate any thoughts on this, thanks.

It is very possible to install a distributor 180 out and it will still run fine if you move each of the ignition wires (on a 4 cly engine) 2 holes each in rotation, it then fires just as it should. Hope that makes sense. Do you have the timing specs, if so I would do the procedure I mentioned so you can time it with a timing light and know it's correct. Early timing can cause detonation and late timing looses power and makes the exhaust system and muffler much hotter.

 

[antfarmer2]

It is very possible to install a distributor 180 out and it will still run fine if you move each of the ignition wires (on a 4 cly engine) 2 holes each in rotation, it then fires just as it should. Hope that makes sense. Do you have the timing specs, if so I would do the procedure I mentioned so you can time it with a timing light and know it's correct. Early timing can cause detonation and late timing looses power and makes the exhaust system and muffler much hotter.

Wbecker is right figure out if you are picky or if not broke don't fix it always better to do it right

 

[antfarmer2]

Wbecker is right figure out if you are picky or if not broke don't fix it always better to do it right

Also I think that one has a timing belt if so won't be long before it is trash

 

[brdgbldr]

Also I think that one has a timing belt if so won't be long before it is trash

Yes, it does have a timing belt. I was planning on tackling that next summer. That's probably how the pulley got put on wrong. Now it looks like it may be more work then what I was planning on. I'm also going to replace the points with an electronic igniter. Thanks again for all the brain storming. If there is anyone out there with a Mitsubishi 4g32 in their skid-steer, please take a look at the crankshaft pulley and tell me what the timing mark looks like. Maybe the wrong pulley is installed...

 

[antfarmer2]

Yes, it does have a timing belt. I was planning on tackling that next summer. That's probably how the pulley got put on wrong. Now it looks like it may be more work then what I was planning on. I'm also going to replace the points with an electronic igniter. Thanks again for all the brain storming. If there is anyone out there with a Mitsubishi 4g32 in their skid-steer, please take a look at the crankshaft pulley and tell me what the timing mark looks like. Maybe the wrong pulley is installed...

Check the firing order if what wbecker and I think happend if you 180 the the dis and fix the wires might buy you some time

 

[wbecker319]

Check the firing order if what wbecker and I think happend if you 180 the the dis and fix the wires might buy you some time

 

[wbecker319]

Check the firing order if what wbecker and I think happend if you 180 the the dis and fix the wires might buy you some time

If this is the Mitsubishi engine, my book says the timing is 5 deg. BTDC with the vacuum hose disconnected, at 600-650 RPM. With the vacuum hose connected, at 2800 RPM it should be 10 deg. BTDC. It says there is a "notch" on the crank pulley for the timing. Also, I doubt that you could put the pulley on wrong as I suspect the 4 blot holes will only go one way.

 

[frogfarmer]

If this is the Mitsubishi engine, my book says the timing is 5 deg. BTDC with the vacuum hose disconnected, at 600-650 RPM. With the vacuum hose connected, at 2800 RPM it should be 10 deg. BTDC. It says there is a "notch" on the crank pulley for the timing. Also, I doubt that you could put the pulley on wrong as I suspect the 4 blot holes will only go one way.

If you locate TDC you can mark the pulley with marker/chalk and go from there. If it is timed 180 out I doubt it would have run well for a year. TDC is only regulated by the crank so it will be a constant. All valve related components can become out of spec through several scenarios. If the belt has slipped everything is off. If the distributor is installed wrong or set improperly that will throw the mark off. I would install some sort of measuring device to locate TDC of the #1 and #2 pistons and see if the notch in the crank pulley lines up to either. A piston stop is ideal but a screw driver in a plug hole will get the job done. If the notch doesnt line up with either cyl I would assume the notch is located incorrecctly or not for this purpose. Then I would verify when the #1 cylinder was on compression with the TDC mark on the crank pulley and set the initial timing from that. The machine should start and run at this point and you can use "your" marks on the crank pulley with a light. If the pulley lines up with say the #2 cyl just use that cyl to operate your light on the factory pully mark. Hope some of that helps.

 

[brdgbldr]

If you locate TDC you can mark the pulley with marker/chalk and go from there. If it is timed 180 out I doubt it would have run well for a year. TDC is only regulated by the crank so it will be a constant. All valve related components can become out of spec through several scenarios. If the belt has slipped everything is off. If the distributor is installed wrong or set improperly that will throw the mark off. I would install some sort of measuring device to locate TDC of the #1 and #2 pistons and see if the notch in the crank pulley lines up to either. A piston stop is ideal but a screw driver in a plug hole will get the job done. If the notch doesnt line up with either cyl I would assume the notch is located incorrecctly or not for this purpose. Then I would verify when the #1 cylinder was on compression with the TDC mark on the crank pulley and set the initial timing from that. The machine should start and run at this point and you can use "your" marks on the crank pulley with a light. If the pulley lines up with say the #2 cyl just use that cyl to operate your light on the factory pully mark. Hope some of that helps.

Update.....the distributor is installed correctly. I checked the number one piston at tdc and the sharpie line was dead on. So I guess I have a pulley that has no timing mark on it. I also went ahead and replaced the points with an electronic Ignitor and a new coil. I went with a PerTronix brand and I must say I was not happy with the instructions or the fact that the adjustment hole was too small and I had to file it so I could get the proper gap, or for that matter, any gap. The wiring instruction for the coil and Ignitor contradicted one another about weather to leave in the resistor or not......leave it in and make sure you connect the red wire from the igniter to the ignition side of the resistor and not to the coil. If having to screw around with the brand new Ignitor wasn't bad enough my starter died while messing with it. Luckily when I got this at the auction it came with a spare starter. Now I'm happy to say that everything is running great. Thanks again for all the brainstorming.

 

[Dave1234]

I just took my crank pulley off to get behind it yesterday. It has 4 bolts holding in on, and no keyway so you can reinstall it correctly, or 90, 180, or 270 degrees off. Mine had a paint mark on the crank and pulley that made putting it back correctly easy. The timing mark for the ignition timing must be on the pulley because the index marks are on the plastic timing belt cover adjacent to it. Look around for a mark on the pulley and reinstall the pulley with the engine at TDC and the mark lined up with teh index marks on the plastic cover.. Then if you need to, take your distributor out and reinstall it so the rotor points at #1 spark wire location once reinstalled. Note that it is driven by a bevel gear, so will rotate some as you install it. You have to rotate it a little off of where you want to end up as it engages the drive teeth as you slide it in so that its rotation will line it up once in place. Marking where the rotor pointed before removal then as removed is the best way if you know to do it, but trial and error re-installation works fine. Just be sure you are at TDC on compression on #1 cylinder.

And, when you dive into your timing belt, you will find a round flat punch mark on the face of the rim of the cam that is supposed to line up with a small indent on the top of the sheetmetal cover behind it at TCD, and here's the real trick--the only mark on the crank for belt installation timing is a small center punch mark on the surface of one of the timing cog teeth on the crank, which you can't see with the belt in place, and would never notice if someone didn't point it out to you. I think you are supposed to adjust the crank location and cam locations, then put on the belt. Would be ok on a tight engine, but a worn one wants to move as you fight with it. Its easy to wind up one tooth off on the crank, which will result in 1/2 a tooth off on the cam location which doesn't look too bad relative to the mark the cam is supposed to line up with, but not quite right. You will be tempted to wonder if it is ok, but when it is right there is no question. FYI, It will run either way.

Good luck.