AQ225 won't start

[Hubcap]

Have 1987 3270 motoryacht with aq225 305 gm engine that won't start. Had it running, turned it off and now won't start. Changed plugs, points, cap, wires and rebuilt the carb ( it was due) changed fuel filters, yes it does have gas. Jumped from coil plus to battery still no start. Tried starting fluid still nothing, convinced it is electrical. Put a spark tester on both coil and plug lead got spark to 3 no problem except color was yellow, definately not a good strong blue. Looking for any help or suggestions.
Thanks in advance. Mike

[Pcpete]

I think I’d change the coil. I had a similar problem some years ago and did many of the things you have done. I don’t see where you checked the timing, but I’d go with a new coil first. Then, if that works, do the same to the other engine.

[2850Bounty]

Which ignition systems do theses have?
Original OEM may have been either Mallory or Prestolite.

Pictures may help if you are not certain.

I would also be inclined to think that if your spark is yellow, you may possibly have a bad ignition coil.

If these are the old Kettering style (contact points) ignition systems, be sure to adjust the points using a dwell angle meter.
If contact points, you will also have a condenser inside of the distributor that will affect the quality of the spark.


.

[Hubcap]

Thanks for info. I put on a new coil, ballast resistor and rotor plus put a new battery in still no start. Used jumper cable from battery terminals to the starter and ground in case the cables were bad, no go. Checked the timing all good. Lost at this point, does anyone have a wiring diagram for the ignition system on a 1987
bayliner 3270 with volve 225 305gm. I found one for a diesel but not gas. There is nothing electrical left to change, fuel is definately not the issue.
The distributor is a prestolite 18m 7013 7 w.
Suggestions please???
Thanks Mike

[Pcpete]

About the only thing left is timing. If there’s power getting to the plugs, it should fire up as long as the spark is correct. I had a similar problem with one of my 4.3’s. I finally loosened the distributor and rotated it while one of my sons cranked it. I went about five or ten degrees clockwise and it fired right up. I have no idea what caused the timing to move like that, but I never needed to touch the timing again. Every time I checked it, it was bang on. That engine had electric sensor ignition so points weren’t an issue, however, in your case the variation in the point gap will throw the timing off. I was taught points, then timing. Adjust the points for wear, adjust the timing.
So. I suggest you recheck the points and make sure they are flashing, check that you didn’t knock the rotor contact to pin out of position then, bring the crank to number one top dead center and check that every plug wire is in the proper port, and in the correct rotation, on the cap.

[Nauti_Mike]

Using a timing light check for spark on each plug wire, if ok timing is where you need to focus. Verify firing order of plug wires at the distributor cap. Then verify rotor is pointing to plug one with the engine at TDC.

[Hubcap]

Thanks guys, I'll try your suggestions tomorrow and report back.
Mike

[builderdude]

Wonder if the chain has jumped, usually happens upon shut down.
🤔

[2850Bounty]

Thanks for info. I put on a new coil, ballast resistor and rotor plus put a new battery in still no start. Used jumper cable from battery terminals to the starter and ground in case the cables were bad, no go.
Checked the timing all good.
Mike, how did you check the timing since you have not been able to start this engine?

Lost at this point, does anyone have a wiring diagram for the ignition system on a 1987
bayliner 3270 with volve 225 305gm.
I have tried to find a schematic for you, but cannot find the correct one.

With key switched to run position, you should see resisted voltage at the + terminal of the ignition coil. This may vary depending on the contact points being open or closed.

With the starter motor engaged, the "start by-pass" system will send a full 12 volts to the down-stream side of the ballast resistor and to the coil + side.
This is a temporary 12 volt supply during heavy amp starter motor action.


There is nothing electrical left to change, fuel is definately not the issue.

The distributor is a prestolite 18m 7013 7 w.
I cannot find anything under that p/n ending with the w.
The closest that I see is this:




Item #4 is the contact points. Adjust these using a dwell angle meter. Check the vertical shaft for any signs of excessive slop.
Item #5 is the condenser. It must be good. Replace it if questionable.
Item #8 takes the points/condenser to the Negative side of the ignition coil. Make sure that the insulation and the little grommet on this wire are good.

If these carburetors are equipped with electric choke (actually an "Un-Choke" ) systems, temporarily unplug the helix heating element wire.
This will help eliminate the heating element as a heavy amp draw that may affect the ignition coil's performance.

If the alternator receives field circuit power from the ignition source, temporarily unplug this circuit from the alternator.
Loosen the alternator belt also so that it is not turned up to speed.

Make sure that your "start by-pass" circuit is working correctly.

Questions:
Has anyone made any changes to the spark plug cabling regarding the firing order?
Are the distributor cap and rotor correct for this Prestolite distributor model?
Is the high tension lead (from center of cap to coil) good?
Are the contact points opening and closing correctly? (set with dwell meter only)
Is the starter motor spinning the crankshaft fast enough for a start up?
By chance are these the old Bendix style starter motors?




.

[builderdude]

Another thought: if equipped with a mechanical fuel pump there should be a vent tube that runs from the pump up to the air horn of the carburetor. Ensure there’s no fuel dumping into the carb from this hose causing flooding.

[Hubcap]

Update:
I removed the new dist cap and found 3 posts had bad rub marks on them. Tried to check points gap and found them closed. Went to remove the rotor to find the shaft moved enough to open the points.
So, I believe the shaft bearings are worn out causing the shaft to run erractically enough to make rotor hit posts on the 3 in question plus causing the points not to open properly.
Based on this I removed the distributor and found the shaft moves almost 1/8 inch. Looking for another one.
Am hoping this is the problem.

Rick
The wires are in the correct order of the firing order.
Compared the new parts from the old, all looked the same, napa supplied them after researching.
New wires for coil and plugs
Points as discussed above
Yes starter is spinning motor properly
Not sure about the starter make.

Dave
No flooding all good.

Many thanks to all, once I get a replacement dist I hope this will solve the problem, will keep you advised.
Mike

[builderdude]

Sounds like you found the problem

[2850Bounty]

.............

Update:
I removed the new dist cap and found 3 posts had bad rub marks on them. Tried to check points gap and found them closed.
Like said, use a dwell meter and adjust for the correct dwell angle. This can be done with the engine being cranked by the starter motor, or running at idle.

If you are Hell Bent on adjust for point gap, the little friction block must be on the high side of the cam.
This means that you may need to bump the starter motor a bit.

Went to remove the rotor to find the shaft moved enough to open the points.
You mean rotated enough to open/close the points???

So, I believe the shaft bearings are worn out causing the shaft to run erractically enough to make rotor hit posts on the 3 in question plus causing the points not to open properly.
If you see excessive UP/DOWN movement, pull the distributor out and look to see if the thrust washer (between the driven gear and the housing) is in place.
If the thrust washer is there, you can replace it with a thicker one as to eliminate most of that Up/Down play.

Based on this I removed the distributor and found the shaft moves almost 1/8 inch. Looking for another one.
May we assume that you mean 1/8" up/down, not side to side?
See my above comment.

Am hoping this is the problem.

Rick
The wires are in the correct order of the firing order.
Compared the new parts from the old, all looked the same, napa supplied them after researching.
New wires for coil and plugs
Points as discussed above
Yes starter is spinning motor properly
Not sure about the starter make.
I asked about the old Bendix style because they DO NOT spin an engine very fast.
Today's HTGR/PMGR starter motors are the only way to go!


Dave
No flooding all good.

Many thanks to all, once I get a replacement dist I hope this will solve the problem, will keep you advised.
Mike

[builderdude]

Good points Rick, I assumed side to side play🤔

[Hubcap]

Rick, the slop is side to side not up and down. Because of this the points gap keeps fluctuating and causing the rotor to not run evenly throughout the cap, hence causing the extra marks on the 3 posts. I do know how to set the correct points gap manually, once engine is running I will check again via dwell.
I have found a used dist in Detroit, should be here by Tuesday, will install and advise.
Will keep an eye on the starter motor to see how it cranks the engine. The other engine cranks the same as the non start one and that engine starts with no problem.

[Chief_Alen]

Maybe time for a new type dizzy.

Maybe a all in one unit with the coil built in, make sure it's marine rated.