Chrysler Project Motor

[DavidW2009]

I just purchased an older Chrysler outboard as a project to learn more about outboards.

The seller doesn't own a boat and never used the motor. He told me it belonged to a friend of the family's who passed away. He bought the motor from the estate.

He said the motor was 2-3 years old, circa late 70's, when a fire broke out in the marina storage and burned a bunch of boats, including the one that had this motor. The outside of the cover is scorched and the cover is no good.

He claims the cover had not been off since the fire. The latch handle is stuck.

I bought it because, except for the cover, the outside looked pretty good. The prop and lower end looked almost new. The motor has been on a pallet outside for a few years. The cover says it's a 75 HP MagnaPower Chrysler.

I brought it home and got the latch to unlatch. Removed the cover and found the insides somewhat sooty, but the wiring, etc. was not damaged.

The motor is a 3-cylinder with (3) carbs. The tag says it's a 90 Brake HP at 5,000 RPM. Model number appears to be: 907HA. The flywheel rotated when turned by hand, so it's not locked up.

I plan on taking this engine apart and seeing if it's any good. The carbs definitely need rebuilding. I built an engine stand for it. The motor came with power lift and trim.

Any experts here who could help me ID the engine? Year, etc.. It's interesting the cover says 75 HP and the tag says 90 HP. (I don't even know if Chrysler had a 90 HP 3-cylinder.)

Edit: Found this website that ID's the motor as a 1974 or 1975, 90 HP.
http://www.maxrules.com/ChryslerModels/90_150.html

 

[Frank Acampora]

Re: Chrysler Project Motor

That's a good little engine. I have one myself. Go by the ID plate--it is almost certainly a 90 that had a 75 cover put on to power a boat rated for less than 90. All the 3 cylinder blocks were the same and different horsepower was derived with different porting and bigger carbs. If yiou turn the flywheel by hand with the engine in gear and the prop turns 1 rev for 2 turns of the flywheel, the lower unit is a 2 to 1 ratio and the engine is most certainly a 90. The 75 ha a 1.7 ratio and the prop turned about 1 1/4 turns for 2 turns of the flywheel.

The Chrysler engines were rated at the engine block, not the prop, so in the 1980s, Chrysler de-rated their 105 4 cylinder and called it the 90.

Before you tear it apart, remove the plugs and pour about 1 teaspoonfull of TCW-3 oil into each cylinder. Rotate by hand to distribute the oil. Next using the starter motor, crank the engine at least 4 turns and check compression in each cylinder with a gauge you can buy at the auro store.

145-155 psi is factory new specification and if it has that, don't do anything. Over 120 is excellent and the engine will run well. 100 or so and it will run but not produce maximum horsepower.

You are looking for equality between cylinders. If one or more cylinders show 60 or less psi, then the engine needs a rebuild.

 

[DavidW2009]

Re: Chrysler Project Motor

Frank,

Thanks for the info. I'll do what you said. Do the throttle plates need to be open while running the compression check?

Is there anyway to get fuel/oil and/or lubricant to the crank bearings before using the starter? This engine has not run since about 1978.

I also need to know how to check for freeze damage, especially in the lower end.

The motor was laying on its side outside for I don't know how long, at the PO's.

I'll post progress on this project on this thread. I'm going to clean it before anything.

I'm looking forward to this project. If the motor turns out okay, I'll buy a good hull.

I noticed this 90 HP clamps to the transom, no thru bolts like on the Force 120 HP.
There is not any provision for thru bolts. (Edit: After I took the transom clamp off, I found there are two mount holes, 1/2" dia., one at the bottom of each clamp.)

 

[DavidW2009]

Re: Chrysler Project Motor

Frank: "The Chrysler engines were rated at the engine block, not the prop, so in the 1980s, Chrysler de-rated their 105 4 cylinder and called it the 90."

So, this 90 HP I bought, in reality may be a 75 HP by the later rating system(?).

 

[Frank Acampora]

Re: Chrysler Project Motor

You will find that a Merc 75 will run just as fast.

Unless there was a significant amount of water in the lower unit, it will not be damaged. As a matter of fact, as long as the lower had some oil, if it was not open to the air, there probably would not be any rust damage either. Compounds in the oil combine with the free oxygen in the water and thus it can not rust.

Carbs do not need to be open. Since it is a ported engine, the cylinders always go to atmospheric pressure at bottom dead center.

Just pour a bit of oil into each carb behind the butterflies and the engine will get lubed adequately the first time it turns over. You would be surprised at just how little oil those roller bearings need.

That engine uses 50-1 gas to oil mix. 1 pint to 6 gallons (48-1)

If you do need to rebuild, and really want to wake up that engine, while you have it apart, modify the ports, square the openings and streamline the inter-port webs with a Dremel and carbide bits. She will then put out an honest 90.

 

[DavidW2009]

Re: Chrysler Project Motor

Frank: "If you do need to rebuild, and really want to wake up that engine, while you have it apart, modify the ports, square the openings and streamline the inter-port webs with a Dremel and carbide bits. She will then put out an honest 90."

Now that sounds like a plan. Then mount it on a 14' Sidewinder Super......

Thanks for the info. This site is a source of knowledge.

 

[DavidW2009]

Re: Chrysler Project Motor

Using a roll-around crane type engine hoist, the Chrysler was lifted on to the engine stand. (The stand is a 1,000 lb. Northern Tool engine stand. With the rotating mount plate pinned in place, a 'transom' made from 2 X 6's and 2 x 4's was bolted on.) The stand holds the 90HP and seems to be stable. The motor swings on the steering pivot effortlessly.

If it doesn't snow tomorrow, the motor comes off the stand and the 'transom' will be lowered a few inches.

Putting a 1 1/16" socket on the flywheel nut, and marking the prop to the housing, the flywheel turns 2 times for every 1 turn of the prop. I noticed I had compression on each cylinder. The shift lever moved easily and I could hear the safety switch clicking. The prop has what looks like a shear pin to hold it on the shaft.

The lower end drain plug was removed to check for water. No water was present, though the oil looks dirty.

I need to get a repair manual for this year motor.

I found a cover to replace the scorched one. The bone yard wants $40. Another place wanted $50, and worst price was $75 from a boat yard that has never given me a reasonable quote on anything.

When I placed the motor on the stand, it was in the lift position. I cracked the hydraulic lines and bled the oil out of the lift cylinders. This slowly let the motor down most of the way and then it stopped. I have no idea why it's not going all the way down.

While the engine is back off the stand, I need to look at the lift closely.

All the wires coming out of the cowl had been cut, so I need to do some wiring to try things out.

 

[Frank Acampora]

Re: Chrysler Project Motor

At 2 to 1, it is definitely a 90. The prop is not shear pin. The prop shaft is splined and that 5/16 pin is a thrust pin. If you hit something, It will not shear to protect either the prop or gears. Yiou can cut the threads and head off a long stainless 5/16 bolt to make an extra pin.

The prop has a rubber hub insert that should slip in the event of a hard hit. These props are not available new and are getting more difficult to find. Spun hubs can not be repaired because no one sells new hubs. Some older prop shops may have one on hand if you get lucky. If you should need a prop in the furure, send me a private message--I have a couple.

Timing is 32 degrees BTDC at wide open throttle. It should have the decal "Electronic" on the distributor. Firing order is 1, 2, 3, top cylinder is #1. Do not overtighten the distributor drive belt--This will cause difficulty in shifting in and out of gear. A .010 feeler gauge pressed against the center of the belt like a finger should deflect it about 1/8 to 3/16 inch before bending.

Buy a Clymers manual. Not the best, but adequately explains carb setting and synchronizing.

ABOVE ALL: These engines are extremely intolerant of lean runs. Never, never, never set the carb low speed needles leaner than 3/4 turn out from lightly seated. 7/8 is better. Too lean WILL result in melted piston(s). Definitely install a cheap disposable plastic fuel filter between the fuel pump and carbs. This prevents one carb from getting junk in it and going lean while the others run well. Plugs are surface gap Champion L20 V Or NGK BUHW ( I think--either BUHW or BUHX) Bent electrode plugs may result in holes melted in the piston baffles.

The engine probably is not going all the way down because the pentagon shaped trim cylinder has a very high mechanical advantage OR--may be jammed in the cylinder. Be careful when re-connecting the hydraulic lines. It is easy to cross thread or strip them. Next time, if the trim motor still works, just jump the wires. Green is down and blue is up. if it is a three wire system, black is ground If it is a 2 wire motor, pos. on blue and neg. on green will raise the engine DO NOT DO THIS WITH A THREE WIRE MOTOR

Engine wiring is standard for any pre 1978 Chrysler: Yellow is start, White is tachometer signal, Orange is overheat indicator, Green is choke, red is power, Blue is ignition (power to Cd box and electronic distributor) and Black is ground.

 

[DavidW2009]

Re: Chrysler Project Motor

Thanks for the info, Frank.

What is the best way to lift this Chrysler motor on and off a stand or boat?

I've been lifting it with heavy duty cargo staps around the lower cowl. But read on this forum that it may be okay to lift using a bearing puller bolted to the top of the flywheel. Will it hurt the motor's crank and or bearings to suspend the motor like this?

Also, how much does a 90 HP weigh? Two of us lifted this motor into my Taurus Wagon, so it can't be too much. (200 lbs.?)

 

[DavidW2009]

Re: Chrysler Project Motor

The Chrysler was lifted off the stand to lower the 'transom'. While off, the lift/trim was looked at to determine why it wasn't going all the way down.

There is what looks like a hydraulic shock/down stop (pancake-like cylinder) centered between the two lift cylinders. There were (4) screws with much thread exposed, holding this cylinder in place(?). The motor looked like it was bottoming out on this down stop cylinder. Without a manual, I'd guess those (4) screws may be jack screws to adjust where the motor stops when all the way down. But I don't know if it's adjustable or not. Just guessing. (It was too cold and it did snow a little here, so I didn't work on it much)

Bought a good used Chrysler motor cover for $40. The boat shop/bone yard I got it from claims to have bought out the entire stock of a Chrysler boat dealer. He claims most of the stock is for 70's motors. He quoted me $85 for a brand new Chrysler prop. for the 90 HP. He said he had several. I thought that was a good price. (Don't need a prop, but good to have a source)

 

[Frank Acampora]

Re: Chrysler Project Motor

The engine itself with power trim and tilt weighs about 275 lbs--two men and a boy can lift it. I manhandle them alone all the time.

Standard practice is to screw a lifting ring onto the top threads of the crankshaft. The top bearing is a ball bearing (standard bearing from a Ford rear end) and locates the crank. you can bolt a puller to the flywheel and lift--I do it all the time. You will find that almost all bearings and seals are standard and can be bought at the local bearing supply store.

The "pancake" cylinder is the trim cylinder and should be (if stock) a pentagon shape held on with five 12 point aircraft type screws they do not adjust anything. The center piston retracts almost all the way into the pancake and no further travel is possible. So, that is as far as the engine can trim down or in. The piston extends about 2 inches out and then the tilt cylinder raises the engine (only when not under load. Tilt cylinder will not hold at anything more than about 1500 RPM.) Tilt cylinder is on the starboard side and a plain shock absorber is on the port side.

85 bucks is good for a new prop or New Old Stock (NOS), a little excessive for a used one. Using that engine on a 15 or 16 footer, you would want to prop around a 17-19 pitch. On a 17 foot or larger, 15-17 pitch would be a start point. Buy a tachometer, regular 12 pole, NOT special 20 pole alternator. Prop to have the rpm at full throttle at or near 5500, that is where the engine produces best power.

Use regular 87 octane pump gas and TCW-3 outboard oil. The engine neither needs nor wants high octane fuel.

While timing for that year was set at 32 BTDC, In subsequent years, Chrysler recommended reducing engine timing advance to 30 degrees BTDC, because of low quality maria gasoline. This is acceptable on that engine.

 

[DavidW2009]

Re: Chrysler Project Motor

Finally getting a bit warmer outside in the carport.

Connected HD jumper cables to the sawed off stubs of battery cable left on the motor. Connected a remote starter push button to the solenoid coil and the battery side of the solenoid. Pulled the plugs and sprayed WD40 into the cylinders. Sprayed WD40 into the carbs. Hand cranked the motor several times.

Hit the push button and the starter turned the motor normally. Had to spray some WD40 on the starter drive shaft. Drive kept sticking in the engaged position. After a few more times, the drive was disengaging normally.

Pulled the Champion L20V plugs (look like new) and ran a compression test with the motor at 43 deg F ambient temperature. Test results:

#1 (top): 120 lbs.
#2 (mid): 130 lbs.
#3 (bot): 130 lbs.

Used a screw-in type compression gauge. Ran the test two times and got the same results.

With the Blue Ign. wire touching positive, the motor was cranked with a spark plug connected to the plug wire and grounded to watch for spark. There was none. This motor has a solid-state CD ignition, or is suppose to. Need to pull distributor cap and take a look.

For a motor that hasn't run since 1978, I am pleased with the compression.

After the spark problem is fixed, the carbs and fuel pump will come next. The throttle plates (or something else) is sticking and the throttle doesn't move much.

I took a bunch of photos of the motor for reference, before taking anything apart.

I called a boat yard on buying a control for this engine and pricing out a used CD module. The yard wanted $175 for the controls (with ignition) and $150 for a used CD. Just fishin'.....

 

[Frank Acampora]

Re: Chrysler Project Motor

Well, before you start pricing a module, always troubleshoot from simplest to most complex So: if you have no spark, the first thing to check is that all wiring is correct. As I said, Blue is power to distributor and CD box. If you jump it to red on the engine terminal board, it should then have power. Now: if the distributor has one wire going to it, it is points signal to the CD box. If it has two wires and says "Electronic" it uses a shutter and electric eye to signal the distributor. If it is points, clean and gap them to .014. If it is electric eye, there is nothing you can do.

Be certain the red wire to the CD box is connected. Red powers the capacitors and blue only powers the switching transistor.

 

[DavidW2009]

Re: Chrysler Project Motor

Frank,

The wiring looks all OEM original. There's not one thing that looks reworked.
The wires are still soft and pliable.

I'll connect the red wire tomorrow and see if there's spark.

 

[DavidW2009]

Re: Chrysler Project Motor

Connected the red wire and blue wire to a 12 VDC source, made sure the shift lever was on the safety switch and cranked the motor over. No spark.

Removed the distributor cap and with a mirror, saw that it does have a point set. Could not tell the condition of the points, but the inside of the cap looked like it has not had much, if any, use.

It seems awkward to R&R the points with a distributor facing down. Do mechanics install the points upside-down like that? (Need to get a Clymer manual asap.) I think I'll pull the distributor and check it out.

All the electrical connections on the ignition system need to be cleaned.

I want to get this motor to at least fire, before taking it apart and cleaning it up.

**********************

The used motor cover I bought looks almost identical to the scorched original one, except its a few years newer and says "Force" on it. But it will not fit. The front and sides are okay but it's 1/4" or so too short lengthwise and will not go over the seal on the lower cowl and clamp in place. The damaged one that came with the motor fits fine over the seal. The boat yard says they will exchange it.

 

[DavidW2009]

Re: Chrysler Project Motor

That was easy.

First did a search of the Chrysler Forum using the term, "distributor". Found a good description on how to R&R the distributor and set the timing.

Pulled the distributor and bench tested it for resistance across the contacts. Found there was no contuctivity at all. Inspected the points and saw a coating of black grud on both contacts. Spray cleaned the contacts with brake cleaner/parts cleaner.

Wiped off cleaner with rag. Contacts looked like new and were shiny. Cleaned off the contacts again and let dry.

Applied very small amount of dielectric grease to felt pad on points. Cleaned the distributor cam and lightly coated it with dielectric grease. Re-installed the points and set to .010".

Bench tested distributor for conductivity. Got '0' OHMs when points were closed.

Re-installed distributor and set belt tension to the .010" feeler gauge criteria.

Applied power and rotated motor until the contacts opened.

Got fire across the test plug. Nice blue/white spark. What good fortune. It appears the MagnaPower is still functioning.

The crud on the contacts was probably from distributor grease in the felt pad or on the cam. There was still an accumulation of old grease on both. Had to clean it off.

I figure the way the motor was laying on its side all these years at the PO's, in the hot sun, the grease dripped down onto the contacts.

The carb linkage was free and moveable, almost normal after working it a bit. It has been soaking with WD40 for several days. My first thought was the throttle valves were corroded or something. But it was a very stiff linkage. Just needed some oil.

Frank, How much (if any) mechanical resistance is there suppose to be in the distributor advance? This 90 HP distributor has some resistance to it. Is it suppose to rotate freely?

Thanks for your posts elsewhere on the forum. Very helpful since I have never worked on an OB, other than simple maintenance, in my life.

 

[Frank Acampora]

Re: Chrysler Project Motor

SEE! I told you not to jump to confusions! Test simplest first.

When the linkage from the tower to the distributor is disconnected, the distributor should move easily and silky smooth. Any resistance to movement will cause binding of the tower linkage and trouble shifting into and/or out of gear.

If there is excessive resistance to movement, set the engine to TDC so the pulley lines up with the flywheel. Remove the pulley, remove the top circlip, remove the distributor body and clean out the bronze bushing inside the mount. Clean the distributor body. Then apply a light coat of grease to both parts and reassemble. NOW pump one or two shots into the zerk fitting on the side. Now, reattach the pulley to the shaft, lined up as it was before. Doing this will not change timing nor change the tension on the drive belt.

BTW: Chrysler used several versions of electronic ignition that they called "Magna-Power." The version you have is a slightly early one and relatively reliable. However, points, even though they are used for signal only, still tend to wear and lose setting, necessitation re-gapping. If at some future time you wish to convert to the elecronic distributor, which will never require re-gapping and is a bit more precise than points, all you need to do is find a used electronic distributor. NO wiring changes are necessary.

 

[DavidW2009]

Re: Chrysler Project Motor

Thanks again, Frank.

The distributor will get cleaned next, per your instructions. Then on to the fuel system. Once the fuel system is operative, I'll try running the motor for a few minutes. (I'm going to stay with the points for now. If I start doing some 'hot rodding' mods to this motor, I'll go electronic.)

Connected power and ground to the Lift/Tilt motor and it hummed quietly. It sounded normal in both directions. (the reservoir needs to be refilled and bleed the air out.) Then try actually lifting on the stand.

The bracket that supports the lift motor/pump is broken. Broke off just below the dog. I hope that doesn't mean replacing what appears to be a good lift motor. If the motor can be removed from the existing bracket, maybe it can be welded.

(I may just fab a bracket and mount it on the transom using a glued mounting plate so as not to put holes in the transom.)

I need advice on pressure washing this motor. I'm thinking, remove all things electrical and tape up holes and ports. Maybe pressure washing is too rough, but not on the inside of the lower cowl.

So far, haven't hit any "killer" problems. I don't doubt now, this motor will run again.

 

[DavidW2009]

Re: Chrysler Project Motor

I am stumped on how to remove the timing gear sprocket from the distributor. There is a 3/8" (either UNC or UNF) Nylok nut retaining the sprocket. It is very tight. I'm not sure how to hold the sprocket or shaft in order to loosen the nut. I don't want to damage anything.

Also, can't figure out what is retaining the rotor inside the distributor. Is it held in place with the roll pin just above the distributor cam?

I did get the advance to start working smoothly by pumping in one shot of high quality lube molylube and working it back and forth.

R&R'd the tower shaft and throttle cam. Found the Nylok nut retaining the throttle cam was way too tight. Linkage now works smoothly even when connected to the distributor advance.

 

[DavidW2009]

Re: Chrysler Project Motor

With the motor off, and in gear, the prop has rotational free play. What is normal when rotating the prop by hand CW and CCW?

I looked thru the Clymers manual for Force and saw no spec on this. Only on how to shim the gears and check the prop shaft end play. (There is just a few thousandths end play on this shaft.)

BTW, The prop that came with this motor is 13" dia X 19 P.