Uh oh - WF won't pull

Scott Boito · Posted: Sun Jan 20, 2013 4:59 pm Post subject: Uh oh - WF won't pull

So I was setting up the motor on my son's kart today and got it where I wanted it and got it running, off and on, a few times. It sounded pretty good, but then I noticed that the outboard install of the clutch wasn't going to work since the keyway on his axle was in a spot that wouldn't match up with the clutch sprocket. OK, so I swapped the clutch to inboard (including the internals) and remounted it. I installed the chain, set the motor so the chain was not loose, then tried to start it.

I almost pulled my elbow out when the string didn't move. At all. I tried a few more times, trying to pull slowly to get any movement, but I got nothing. I loosened the clutch a little to see if I somehow had tightened it too much, but that didn't help either.

So I'm at a loss. The temps were cool today, but I didn't have any resistance earlier in the day and it was the same or a few degrees warmer when I tried later, so I don't think temps are the problem. Definitely seems like something is stuck or broken.

Thanks for any suggestions.
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KM #68 - Haase/Honda kart
BetterOffRacing
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John Matthews · Posted: Sun Jan 20, 2013 5:37 pm Post subject:

First pull the spark plug and make sure you're not hydro-locked, this is where the cylinder gets full of fuel and can't compress a non-compressible fluid.

Next check the clutch again, it's possible you pushed the key into the bearing.

Probably something simple, go step by step backwards from what you did earlier and I'm sure you'll find it.

Cheers,
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John Matthews
Heartbeat Power, LLC.

Chris Hatch · Joined: 02 Mar 2004 Posts: 405

When running outboard (clutch gear towards seat) without the spacer washer I have seen the clutch hit the chain guard bolts and lock then engine. Is it possible something on the seat strut hitting the clutch bolts?

John Matthews · Posted: Mon Jan 21, 2013 8:18 am Post subject:

Scott Boito · Posted: Mon Jan 21, 2013 8:27 am Post subject:

I still have lots of clearance to the seat strut so it's definitely not interference.

I did pull the plug to look in the cylinder. Neither the plug nor the top of the piston were wet.

I haven't pulled the clutch yet to see if that is the problem.

Thanks for the suggestions so far.
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

George Vorrilas · Posted: Mon Jan 21, 2013 8:38 am Post subject: clutch issues

Ditto on checking the spacer that is required when running the clutch inboard. Also check as there is a radius on one side of the washer that matches the radius on the crankshaft.

George V.
ApexKartSports
www.apexkartsport.com

George Vorrilas · Posted: Mon Jan 21, 2013 8:40 am Post subject: clutch issues

Ditto on checking the spacer that is required when running the clutch inboard. Also check as there is a radius on one side of the washer that matches the radius on the crankshaft.

George V.
ApexKartSports
www.apexkartsport.com

David McDowell · Posted: Mon Jan 21, 2013 5:42 pm Post subject:

Scott Boito · Posted: Sun Jan 27, 2013 1:59 pm Post subject:

Finally got some time to tear it apart again to look for the problem. It wasn't the chain or the clutch. I can move the crank slowly, but with a lot of resistance by screwdriver on the starter flywheel, so the piston isn't stuck. I took off the head and confirmed everything was in order there - and the crank still won't turn.

So I'm to the point of removing the crankcase cover, but cannot get it all the way off. I get it about 3/8" and it just hangs. Any suggestions for how to get this all the way off?

Any more suggestions as to the problem with the crank? I was thinking rod, but the piston will move when I turn the flywheel. The pull-string works well off the crank, so that's not it. I need to get to where I can say what is the cause.

Thanks
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

John Matthews · Posted: Sun Jan 27, 2013 6:48 pm Post subject:

If it turns over with a lot of resistance it's gonna be a seized crank bearing, really just the rod on a WF. There's another bearing inside the sidecover that is probably hung up on the crank which is keeping you from pulling it off. Can't really tell you much more without looking at it. Do you have an engine builder or are you going to give it a try yourself?
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John Matthews
Heartbeat Power, LLC.

Scott Boito · Posted: Sun Jan 27, 2013 6:59 pm Post subject:

Willing to try myself - it should have been ready to go so I wasn't planning on any work on it this winter. Just getting it ready for the season when this happened. I have some time with 2-strokes, but this is the first 4-stroke I've played with.

I guess I will pop out the oil seal and see what I can see. Need to get this fixed.
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

John Matthews · Posted: Sun Jan 27, 2013 7:18 pm Post subject:

Removing the oil seal really won't tell you much. If it was on my bench I would go ahead and pull the flywheel, then if all the sidecover bolts are out and it still won't budge I use a small hammer to tap the pto side of the crankshaft until it's free. You may need another set of hands to do this as well since you'll need to support the sidecover, usually with the engine held above the bench with the flywheel side facing down.

How many hours are on this engine?
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John Matthews
Heartbeat Power, LLC.

Scott Boito · Posted: Sun Jan 27, 2013 8:03 pm Post subject:

only supposed to be 1.5 hours on the motor since new. eBay special, but it is pretty clean and everything looks very nice and new.

I want to get the oil seal off so I can pull the cover. Will be able to see the PTO side bearing to see if that's a problem. Other than that I want to see if anything is broken anywhere. I guess it sounds like I will need to pull the other side off too. Yay.
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KM #68 - Haase/Honda kart
BetterOffRacing
Member of the SCCA KAC

Bernie Lacotta · Joined: 21 Mar 2006 Posts: 168

John Matthews · Posted: Mon Jan 28, 2013 7:24 am Post subject:

It's a good practice to go through any used motor you buy before running it. The money saved in parts if you catch something is significant and a good builder may be able to find power you wouldn't otherwise have.

Let us know what you find....
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John Matthews
Heartbeat Power, LLC.