70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

[dgaudi]

I have a chrysler 55hp motor model 55hd that ran great before running into a sandbar on the river with it. We hit the sandbar at about 20 mph and the motor buried itself into the sand and died when we hit and we had to get out and pull the motor and boat out. There was alot of sand in the exhaust. After hitting the sandbar the motor would start however it would sputter and die under the load of the water with any acceleration. We could tilt the motor keeping the intake in the water and it would pump water and accelerate fine, but in the water it would sputter and die under load. After getting it home we took apart the lower unit and cleaned it all out including the intake holes, and the exhaust. The motor will fire up and begin to idle fine, but will die within 10 to 30 seconds. It pumped water before the accident, but will not pump water now. I am going to inspect the impeller and water pump next. If the water pump was out would the motor still run but just overheat? I am trying to determine what might of happened to the motor when it buried itself into the sandbar and what is causing it to start but die right away. I would appreciate any feedback. Thank you

 

[tater76]

Re: 70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

You likely sheared the flywheel key. Usually the prop shear pin will go in an instance like this, but I would bet money that its the flywheel key. The motor will run, but is severely out of timing adjustment and will not run correctly. The key can be found on ebay for a few bucks. Let us know what you find so I know wether to stay home or go to vegas

 

[dgaudi]

Re: 70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

Could you explain where the flywheel key is? I havent got a manual for the motor yet, if not I should be able to find an online diagram. I appreciate the feedback. Do you think that when the motor buried itself it could have pumped sand into the motor head?

 

[tater76]

Re: 70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

The key is actually a woodruff key that aligns the flywheel in a certain orientation with the crankshaft. The key will be found in the crankshaft flywheel mating surface. There are cutouts on both the shaft and flywheel where it rides. Your key will be around 2" long if I remember right, and it also holds the timing cam inplace on the crankshaft. Here is a link to ebay for one, but this is pretty spendy for it. http://www.ebay.com/itm/FLYWHEEL-KE..._Accessories_Gear&hash=item1c1e22564b&vxp=mtr If you need one do some searching for a better price.

If sheared, the flywheel is only held in place by the flywheel nut torque. Even though this is usually around 100ftlbs, sometimes the enertia from a quick stop like you experienced will cause the flywheel to rotate a little on the crankshaft shearing the key and throwing off timing. Also, if this is indeed what happened, then everytime the starter engages it can move the flywheel even further.

To pull the flywheel you will need to remove the nut on top of the flywheel. Then it will require a puller of some type. I use a steering wheel puller from Harbor Freight. You will find three threaded holes on top of the flywheel, these are designed for the puller. Once you have the puller installed and tightened down until it feels like its going to snap, don't be afraid to smack the end of the puller with a LARGE hammer. You won't harm the engine, and sometimes the extra umph is needed.

One its off you will see the key in the crankshaft, or maybe in your case.... half of the key. If its the key, replace it and while you have the flywheel off clean and check the points and gap also inspect all the wires.

I will look for my downloadable version of the manual for you, give me a few.

 

[tater76]

Re: 70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

The manual file is too large to attach, so it will have to go email. PM me if you want a copy.

 

[Tmacular]

Re: 70's Chrysler 55HP motor model 555HD problem running after hitting sandbar

I pull my flywheel by gently using a prybar and slowly lifting each side until its loose (if you dont have a puller like me). I just replaced my key as well, and being a novice it was VERY simple. Just be careful taking the flywheel off and the key will be sitting right under it. You most likely wont miss it because it will be in pieces. Thats how I found mine