Chrysler Outboard does not get full RPMs

JGKoenig · Jul 6, 2002

I have a freshly rebuilt 1983 Chrysler 140HP Outboard. All cylinders are bored 20 over and compression is excellent. I get up to about 4500 RPMs very quickly, but do not seem to have any more. I am running a 19 pitch cupped prop, the book recommends a 21 non cupped or 19 cupped so I don't believe the prop is the problem. It does not break up at the high end at all, it just seems to stay at 4500 RPMs. Any Ideas!!!

lepper · Jul 6, 2002

Re: Chrysler Outboard does not get full RPMs

Well, I would think it might have something to do with your prob. See if someone won't let you try one to see if that does anything. On my motor I ahve a 21 pitch prob. and my max rpms are 5000, I can trim it up to 5500+ But I figure 45mph is fast enough for me on the water..... so i am just going to leave it where it is..

JGKoenig · Jul 7, 2002

Re: Chrysler Outboard does not get full RPMs

Thanks, I will try that. I thought that a smaller pitch prop would drive the RPMs up instead of down.

sony2001 · Jul 7, 2002

Re: Chrysler Outboard does not get full RPMs

Timing is 32 BTDC, try higher octane, butterfly valves open all the way in the carbs, and try a 19" non cupped.!!!!!!!!!!

JGKoenig · Jul 8, 2002

Re: Chrysler Outboard does not get full RPMs

The butterflys were the first thing I checked because of the old controls, but they are opening all the way. Right now the timing is set to 28 BTDC. Its kind of wierd. The owners manual says 32 the service manual says 30 and the guy who sold me the parts for the rebuild said 28. I will definatly try advancing it to at least 30. thanks for the suggestion.

JGKoenig · Jul 9, 2002

Re: Chrysler Outboard does not get full RPMs

I advanced the timing, but it didnt really make a difference. It is now set at a little over 30 BTDC. I also removed the in line fuel filter I had added, but that didnt work either.

sony2001 · Jul 9, 2002

Re: Chrysler Outboard does not get full RPMs

The timing was lowered because poorer fuel showed up in the market. I don't let the octane slip below 89, prefer 32 degrees and don't have any preignition ping in the motor. As for your rpm, its in the wot range of 45 to5500. Could it be that everything is still tight and it will speed up later?

JGKoenig · Jul 11, 2002

Re: Chrysler Outboard does not get full RPMs

You are probably right, that everything is still a little tight. I am going to readjust the timing to 32 BTDC. I am a little shy with the timing because I burned holes in 2 pistons on the last rebuild because aI had it too advanced. I am also going to clean the carbs and put a new cap wires and rotor on it. That should help things, thanks for the info.

JGKoenig · Jul 23, 2002

Re: Chrysler Outboard does not get full RPMs

OK I have tried just about all of the suggestions and still am missing some RPMs. Could it be something in the distributor (maybe some kind of timing advance)? Maybe even a float setting or something? Any suggestions?????<br />HELP!!!

sony2001 · Jul 23, 2002

Re: Chrysler Outboard does not get full RPMs

My 125 enjoys the 17" prop. Your 140 should be a 19". I have high compression and am not at the top of rpm range. If book recommends 19" cupped, look for other books. For skiing with a load definately it should be a 17", from experience and the prop catalogs that I've read.

Bry21317 · Jul 24, 2002

Re: Chrysler Outboard does not get full RPMs

I have an 88 Force 125 HP on Bayliner 19.5' Capri and only can get to about 5000 RPM's with a Hustler 13 1/4 x17 Pitch prop. But she will get up and run out of the hole pretty fast. Tops out around 40 or a hair over. I would love to find away to get it up closer to the 5500 RPM's, but I'm not sure how to. This is with it trimmed all the way up to, as high as I can without loosing the water. I have also added Boyeson reeds which did give me about 300 Rpm's and one **** of a hole shot. Before that it wouldn't hardly pull me up on the wakeboard (200lbs) but now it jerks me out of the water, faster than ever, as a boat should.<br /><br />Thanks,<br />Bryan Cox

schmoedog · Jul 24, 2002

Re: Chrysler Outboard does not get full RPMs

Hey! That was my question for today. Ha Ha. I have a 79 Merc 115. I was running about 4300 rpm. It was really slow out of the hole. I advanced the spark and got to about 5000 rpm. I have a 19 prop. Do you think a 17 might be the answer. I want to pull skiers with a load. BTW the 5000 rpms shot me right out of the whole but top speed is only about 32 mph but it's a heavy Wellcraft boat,16 footer.

sony2001 · Jul 24, 2002

Re: Chrysler Outboard does not get full RPMs

The difference between my 17 and 19 is 1 mph, but everything else is better.

Chrysler Outboard does not get full RPMs

Seaman

Petty Officer 3rd Class

Seaman

Chief Petty Officer

Seaman

Seaman

Chief Petty Officer

Seaman

Seaman

Chief Petty Officer

Chief Petty Officer

Seaman Apprentice

Chief Petty Officer