Can't get the engine to turn through

[birdmannn101]

All set to check out these carbs so I hooked up one of those jumper batteries and the thing showed 12 volts.  Hit the starter and the engine went slowly "rrrrrrrrr-rrrrrrrr-rr" and that was it.  Thought the jumper battery was bad so I checked it again and it showed 12 volts.  Borrowed a ride-a-mower battery off a friend and it shows slightly over 12 volts.  Hit the starter and the engine went slowly "rrrrrrrrr-rrrrrrrr-rr" and that was it again.

Laid the positive side of the battery of the jumper cables directly to the starter side of the magnetic starter solenoid and got the same thing.

When I was turning the engine over with a wrench to set the point gap and the timing it felt a little hard to turn.

I haven't tried jumping it with a car battery.  I have never ran across this situation before.  Any suggestions???

[TOOLS1]

Your battery cables, or their connections could be bad. Or your starter motor is bad. However worst case is you have an internal engine problem. I would start with testing the starter. Another thought, does it kick over with the kick starter?
TOOLS

[birdmannn101]

I don't have a kick starter.  It is a Hondamatic and didn't come with one.

I wouldn't think the battery cables would be bad if it didn't crank any faster connecting directly to the starter.

I'll take the starter out of the engine and see if it spins faster when connected directly to the battery without having the drag of the engine to slow it down.

Internal engine problem - What do you think the problem could be with slowing down the cranking?

[LukeM]

Your third sentence is the best way to diagnose the starter.  You can test it lying on the ground, or use a vise to hold it steady. It generates a LOT of torque (by design), and should spin freely with your motorcycle battery.

IF you try to use a car battery to jump start your motorcycle, be sure the car's engine is NOT RUNNING when you do so.  The cycle's wiring harness can't handle more that 30 amps, and a car's alternator can deliver more than that when idling.

If it spins freely, the problem lies elsewhere.  Perhaps something is binding in the starter/clutch area.  I would hate to think the motor is seized up.  That's a pretty expensive fix if it is.

Luke M

[TOOLS1]

The kickers for the Hondamatics are rarely with the bikes any more. Just like the tool kits they are removed from the bike, and never put back. I have seen them on ebay, but they usually go for around $60.00. However they are worth it.
As for hooking the jumper cable directly to the starter, did you also hook the ground cable directly to the starter?
TOOLS

[birdmannn101]

Thanks LukeM,

I remember warnings about using a car to jump a motorcycle but never heard why.  I'll be pulling that starter today.  Hope I can get it out without having to pull the carbs again....LOL

[birdmannn101]

I didn't hook the negative to the starter but I did connect the negative to the gear change pedal just to make sure that the negative battery cable wasn't causing the problem.

TOOLS1 wrote

As for hooking the jumper cable directly to the starter, did you also hook the ground cable directly to the starter?
TOOLS

[TOOLS1]

"THE GEAR CHANGE PEDAL?" That is not really a solid connection, and I doubt electricity arcing across the gears, and bearings inside the engine will it any good. The best place to connect a ground is a motor mount.
TOOLS

[Re-run]

You CAN jump from a car battery just fine, BUT the car must be off. It is only an issue if the car is running and actively charging. You could hook a 12 volt battery the size of the Titanic to a bike without an issue as the bike will only pull what it needs. It's the amount of charging amps that wreck things on a bike.

[birdmannn101]

Took the starter out after removing the carbs, oil pressure sending unit and cam adjuster.  Guess What!  It works just fine.  Put it back in the slot and tried to turn the engine and it barely turned.

A friend came by and suggested taking a plug out and try it.  I did and it started turning over.  I pulled all plugs and squirted all the cylinders and the intake and exhaust valves with WD-40.  Cranked it again and it sounded good.  Later I put some Marval Mystery Oil in the cylinders and cranked it again.  Still sounded good.

Put the plugs back in and carbs back and cranked it again ... It is back to barely cranking.

I know this engine will probably needs to be taken out of the frame to remove the head so are there any suggestions on what to check before I have to do that?

[Re-run]

That sounds like compression is causing the slow turn over. Are you sure you don't have a modded engine with higher compression? If it turns good with no plugs in then slows with them in, then it sounds like compression. Or a weak starter. Your starter might need rebuilding.

[TOOLS1]

I have to agree with Re-run. Did you take the starter to an autoparts store for testing? Why not run a compression check? As for removing the head, it can be done on the matic without removing the engine. Another thought, has someone been messing with the cam timeing? If they have, the pistons could be hitting the valves.
TOOLS

[LukeM]

Negative post of the battery to the outside metal of the starter.
Positive post of the battery to the positive cable of the starter.
Motor should spin freely.  If it binds up, chances are the brushes are bad, or the bearings have seized up.  Kits can be found on EBay or other parts sites for $20-30 US.

Luke M
(who rebuilt the starter on his Avenger in about an hour)

[TOOLS1]

Just a thought, since you do not have the kicker, have you tried removing the points cover, and turning the engine over with a wrench?
TOOLS

[birdmannn101]

Yes, I did try turning the engine over with a wrench (clockwise) and it was harder to turn than normal.  I haven't taken the starter to a shop for testing yet because of the engine being hard to turn.  That will be my next option.  It would probably be better to buy another starter.

I can't get the engine to spin a complete revolution on the starter or turn the engine over with a wrench to get a compression check.  If I had a kicker I could do that.  The engine doesn't appear to be modified.

Tools, thanks for the information that I can remove the head while the engine is still in the frame.  Cam Timing?  Are you talking about timing of the engine?  I did set the timing manually with a light on 1&4 and 2&3.  

One thing that bothers me is the nuts that hold the valve set screws have a coating of rust on them.  I have never run across that before.

[TOOLS1]

On "timeing" I am talking about the cam shaft to crank timeing. If it is off by even one tooth, the valves will hit the pistons. Also if the valves are stuck open, they will hit the pistons. Now another thought, do you have the correct sparkplugs? If they are too long, they could be hitting the pistons.
TOOLS

[birdmannn101]

Oooops!  I never checked the timing of the cam shaft to the crank.  I didn't think about that because the last owner said the bike was running... 

... Of course, they all say that even if it wasn't.  So, since I have never worked on an engine with overhead cams, just push rod engines, can I take the head off and see if the chain matches up with the sprocket some how?

D8EA spark plugs I picked up from Honda so I guess I am okay there.

You have some good thoughts there Tools.  What about the hard to turn shaft?

[Re-run]

I think the question is IF the engine will turn over completely.

At first it sounds like it, then it sounds like it doesn't.

Does the engine turn over completely? If it does, not likely it is hitting valves or anything else.

If it does not, then most likely something physical is jamming it.

I feel like we need to clarify this.

[TOOLS1]

So right Re-run. He needs to remove the points cover, and see if the engine will turn over a complete revolution with a wrench.
Also you can remove the valve cover, and crank the engine over with a wrench to see if the timeing marks will line up.
TOOLS

[birdmannn101]

The engine sounds like it does NOT turn over completely but does turn over completely when I remove one or all spark plugs.

Since there is rust on the valve set nuts could a stuck valve be causing this problem of building up compression and not releasing causing the engine to turn through?

If that might be the problem, what steps would you take to free up that valve?  I only have experience on push rod engines and NO experience on stuck valves.