Chrysler 20Hp runs good expect at high RMP

[B'Haven]

Great Website, I have read a lot of prior posts that have helped.

I have a 1973-74 Chrysler 20HP Model 202HF ? That runs great, idols and starts fine but when at full RPM it will start to lose power and would die if I didn't pump the ball continuosly. I assume it is getting air somewhere but I recently changed the line, bulb and tank with the same problems.

First question: What model of fuel connector (line) and (outboard) do I need?

Second Question: Do you think this could be an obstruction in my carberator or need a new float?

Third Question: Any other ideas to look into?

Any help would be greatly appreciated.

 

[jerryjerry05]

Re: Chrysler 20Hp runs good expect at high RMP

Sounds like the fuel pump is the problem.J

 

[snake eater]

Re: Chrysler 20Hp runs good expect at high RMP

The diaphragm in your fuel pump is hard. it needs to be replaced. I think your carb is fine. If the float didn't work it would just flood the carb.

 

[B'Haven]

Re: Chrysler 20Hp runs good expect at high RMP

Thanks for the help on the fuel pump. I purchased the repair kit from iboats and will replace the parts. Any word to the wise on things to watch out for in this process? Also, I know this question is asked frequently but I still need to ask. I do have some water that comes out my exhaust in the lower leg but it does not seem like much. Should I replace the impeller or is this normal. It has never overheated I am just use to a large stream of water coming out of other motors that makes me feel good about the cooling system.

 

[hunterope]

Re: Chrysler 20Hp runs good expect at high RMP

Make sure your surfaces are Very clean when you put in your new kit. A little speck can ruin your efforts. I'm not a pro on the Force Motors (yet) but I think the little spray your seeing is "normal" or "as by design". Someone else will probably post similar remarks (i hope). Good luck.

 

[moparman]

Re: Chrysler 20Hp runs good expect at high RMP

while your there, you might want to replace the check valves in the pump, the older ones are affected by the alcohol that's blended in the fuel now days. Their not but $5-$6 bucks apiece and are good for peace of mind to not have to worry about them again for a while as the new ones are more alcohol resistant. Just my two cents worth. MOPARMAN ROLL TIDE

 

[B'Haven]

Re: Chrysler 20Hp runs good expect at high RMP

Ok, One thing fixed and another problem created.... I changed out the parts on the fuel pump and now it is running better but while out test running it today it got hot. I noticed that there is no water coming out the top exhaust ports on the motor. I am not familiar with this cooling system on this motor at all. I would assume it needs a new impeller kit but could use anyones help on this issue. Is changing out the impeller on this engine the same as posts about 3 and 4 cyclinder engines? or with this being a 20hp will it be different? If anyone would be willing to give detailed advice I would sure appreciate it. Thanks again for all the help Unbelievable wealth of knowledge on this website!

 

[Frank Acampora]

Re: Chrysler 20Hp runs good expect at high RMP

Look at the attached photo of a Chrysler 50. Can you see the water exiting the relief in the back of the leg? Most of the water exits with the exhaust but there should be a steady stream coming out the idle relief vent at full throttle. Some 20s and 25s do not have a visible idle relief. The water just pours into the leg cover and dribbles out around the bottom.

Time to change the water pump impeller. It only costs about 20 bucks. If you can not find it here at iboats, go over to The Chrysler Crew or contact franzmarine@aol.com.

 

[B'Haven]

Re: Chrysler 20Hp runs good expect at high RMP

Thanks for the picture, no my 20hp is not kicking any water out at all. I think I will change out the impeller and see if that does it. Is taking off the lower unit of this motor going to differ than 3 and 4 cyclinder engines? I have seen and read how to do it on other motors but i haven't seen anything talk about 2-cyclinder engines? Franks post about impeller changing is great and the video on you tube is very helpful to see a visual of the procedure.

 

[Frank Acampora]

Re: Chrysler 20Hp runs good expect at high RMP

It is a bit easier to drop the 20 lower. It is lighter, there are only four bolts, and of coures, the shift rod must be unscrewed.

Assembling, you need to be careful to properly adjust the shift rod. If you don't move the jam nut, you should be close to where you started though.

The water pump is held on with four bolts. The nice thing there is if they are corroded and you snap them, they extend through the case and can be driven out with a punch or drilled. Then, there is enough room on the outside to use a longer bolt and a nut

 

[B'Haven]

Re: Chrysler 20Hp runs good expect at high RMP

Frank once again your knowledge is much appreciated. I dropped the lower unit last night to put in a new impeller. The old impeller was not in bad shape but still changed it out. in the process we noticed that a couple of the leg ports were blocked which was definatly our problem. We cleaned it up put back together and ran it in the tub of water to finally see good discharge. Sunday I will give it the real test but I could not be happier with all the great help from this website. A motor that once was considered ready for the garbage now appears to be running quite well.

 

[AZcamperguy]

Re: Chrysler 20Hp runs good expect at high RMP

just subscribing thanks.