Chrysler 20HP has no speed

[Barry Duncan]

My 20HP Chrysler starts and runs fine but will push my 14ft boat at only a fast troll. I noticed last night that when I unhooked the tank to run the gas out of the motor I was able to speed the motor up and run the boat fast until the gas ran out of the motor. It would seem like an obstruction in the tank or hose but why does the motor run normal when I unhook the hose? I would appreciate any info or help. Thanks.

 

[roscoe]

Re: Chrysler 20HP has no speed

Is there a vent on the tank? There should be. It must be open to allow air into the tank to replace the gas that is being sucked out. Otherwise it creates a vacume and restrict fuel flow.<br /><br />Other problems could be dirt in the tank creating an obstruction on the fuel pickup, a partial clog in the fuel line.

 

[Barry Duncan]

Re: Chrysler 20HP has no speed

Originally posted by roscoe:<br /> Is there a vent on the tank? There should be. It must be open to allow air into the tank to replace the gas that is being sucked out. Otherwise it creates a vacume and restrict fuel flow.<br /><br />Other problems could be dirt in the tank creating an obstruction on the fuel pickup, a partial clog in the fuel line.

 

[Barry Duncan]

Re: Chrysler 20HP has no speed

Thanks for your response. There is a vent on that tank which is open. I even tried running it with the gas cap off with no different results. The puzzling thing is that it must be getting enough gas into the motor because when I unhook the fuel line from the motor when it is running the motor speeds up normally until it runs out of gas.

 

[Oldsaltydog]

Re: Chrysler 20HP has no speed

Sounds like the problem is the pick-up tube and the coupling assembly at the gas tank. Borrow another tank and hose assembly and see if it helps. Or your fuel pump may be weak. How's your inline filter? (How are things on Minnesota Ave?)

 

[Barry Duncan]

Re: Chrysler 20HP has no speed

Originally posted by Boat builder Barry:<br /> My 20HP Chrysler starts and runs fine but will push my 14ft boat at only a fast troll. I noticed last night that when I unhooked the tank to run the gas out of the motor I was able to speed the motor up and run the boat fast until the gas ran out of the motor. It would seem like an obstruction in the tank or hose but why does the motor run normal when I unhook the hose? I would appreciate any info or help. Thanks.

 

[Barry Duncan]

Re: Chrysler 20HP has no speed

Thanks for the advice. I put a new tank on with fresh fuel and am having the same results. The motor starts right up, idles fine, but will only run at a fast trolling speed. When I unhook the fuel line from the motor when it is running it will then speed up until the gas runs out of the motor. Any other ideas? Also, I changed the lube in the lower unit and now when I run the motor lube ozzes out of, what I think, are the vent holes. Did I overfill it? I took out both plugs and squirted it in from the bottom until it came out the top plug hole. I then put the bottom plug back in and topped off the top hole. I have taken the advice of other post replies and ordered a Seloc manual for this motor. Thanks again for all the help!!

 

[scotiany]

Re: Chrysler 20HP has no speed

Or, it could be the fuel pump diaphragm. Strange problem though.

 

[eurolarva]

Re: Chrysler 20HP has no speed

take a whiff of that suspected lower unit oil. I bet is smells like gas. It is probably unburnt gas and oil coming out. It is probably white and frothy. IF it smells like gas this is normal to some extent. you can not over fill the lower unit so dont worry about that. Get a fuel pump kit. I believe you have a single stage pump and the kit is a 18-7805. Iboats sells them here is a link chyrsler fuel pump kit 20 HP <br /><br />Also you may want to consider getting a new fuel bulb. I have neard that like 1 in 20 new ones are defective

 

[rbruce63]

Re: Chrysler 20HP has no speed

Perhaps it's time to check compression on your Chrysler 20 and compare it with the specs. If there are leaks in the main seals your'e probably loosing primary compression and the combustion chambers are not filling correctly and you are loosing power.

 

[Barry Duncan]

Re: Chrysler 20HP has no speed

Thanks for all the good advice. After trying everything suggested I finally took it into the shop to be checked. The carb was all gunked up inside so they cleaned it and it runs great now. Their explaination for it running better when the fuel line was unplugged is that the gunked up carb couldn't suck fuel through the line and created kind of a vacumn situation. Unhooking the fuel line relieved the vacumn and allowed it to run off the fuel in the motor.