Chrysler 20HP dead in the water.

[i386]

Model: 202HD<br />S/N: 2143<br /><br />Today on the lake I was running at almost full speed when I heard a rattling sound followed by the engine quiting. I pulled the cowl cover and the flywheel was loose enough to be removed without a wrench. The key was also sheared. After getting a tow back to the dock and getting the boat home I took another look at it. I removed the spark plugs and slowly turned the crankshaft. It does not seem to be siezed up. Both pistons move freely. Could this happen just by the flywheel nut vibrating loose? Should I pull the head and check for scoring of the cylinder walls? I really don't know what to do next. Any suggestions would be appreciated.

 

[eurolarva]

Re: Chrysler 20HP dead in the water.

Chances are there were minimal or no damage done other then the flywheel key. You are going to have to replace that. When you replace it do a good visual inspection to verify nothing else is broken. When you replace the key make sure you torque the flywheel nut to spec. Good luck

 

[i386]

Re: Chrysler 20HP dead in the water.

Thanks! Sounds promising. Maybe I just didn't tighten the flywheel enough when I installed the cam wiper felts. Anyone know the correct size key to buy? Otherwise I could take the flywheel to the hardware store and see if they can match it.

 

[eurolarva]

Re: Chrysler 20HP dead in the water.

I doubt the hardware store will have the correct key. IF they dont try a local merc dealer. Merc number F458498 works on the newer model 20 HP chryslers. This is from a 1978 motor but it should work on yours.

 

[i386]

Re: Chrysler 20HP dead in the water.

Upon closer examination it looks like I'll have to take the whole points/coils business off so I can remove the cam. The key appears to be of the half-moon type and is shared by the flywheel and cam.<br /><br />*The key sheared on the flywheel part, but the cam part is still in tact.

 

[scotiany]

Re: Chrysler 20HP dead in the water.

Make sure that you lap the flywheel and shaft before you reinstall it. Also make sure your stator is secure. It would also be a good time to check the timing. The Seloc manual has the proceedures for theses tasks.

 

[i386]

Re: Chrysler 20HP dead in the water.

Thanks again. I was able to find the part locally today. After fighting with what was left of the key to get it out I was able to lap the flywheel and shaft and re-assemble everything. <br /><br />The muffs I bought today were too big to fit the engine so I sacrificed one of the garage garbage cans. <br /><br />She started and ran like a top after the 4th pull. Subsequent starts were one-handed and nearly effortless. I'm gonna take her out in the morning and see how she really runs. <br /><br />At this point I think all this happened because I failed to tighten the flywheel nut properly. The old gentleman at the repair shop concurred. If anything else pops up I'll let you know.<br /><br />Thanks for your help because I really thought she was gone for good.

 

[i386]

Re: Chrysler 20HP dead in the water.

I'm still waiting for my manual to arrive but I have figured out how to sync the carb with the timing advance and boy was it set wrong. With the throttle backed off all the way the butterfly was partially open. After aligning the follower with the mark on the cam and closing the butterfly it ran better and smoked MUCH less. Of course this also means that at WOT the butterfly isn't opened as much as it used to be but I guess it was never supposed to be opened that far at WOT anyway. I have no tach so I don't know how many RPMS she's turning at WOT but my GPS says we were doing 19MPH (small 14ft fiberglass boat) and that was up the middle of the Chattahoochee where it was choppy. She might run a little faster on the smooth. I'm anxiously awaiting my manual getting here so I can find out what else is set wrong. She might be a good little motor after all.

 

[rbruce63]

Re: Chrysler 20HP dead in the water.

Cut the circular muffs to make them rectangular and compress the muff spring in a Vise Grip to make it fit snuggly in the small lower unit.<br /><br />The butterfly has to be totally horizontal at wide open throttle. Wait for the manual to arrive to set the proper throttle pickup as this is a very important adjustment.<br /><br />The speed seems correct, however, I make up to 21 mph in my Boston Whaler Sport 11 and Chrysler 20. Experiment with the tilt hole setting, I found that tilting the motor leg out one hole helps a bit, perhaps, also raising the motor half an inch to an inch above the bottom of the hull by putting a hard wood spacer will help with your boat and motor combination.<br /><br />Good luck (take the Coast Guard Boater's Ed course) and enjoy your motor!