1960's cushman truckster ignition problem

[aranman]

Below is a pic of the carb

[aranman]

Sparyed all over intake with carb cleaner like you suggested, no noticable change.

So it looks like I need to remove the carb again and inspect.

Strange thing is if I open or close the choke butterfly with my fingers, it seems to make no difference. Like wise with the throttle advance. Its only when I actually move the choke linkage and keep the choke slightly open that it will stay running.

[aranman]

Got it going without the choke.
No sure what did it. I stripped down the carb and cleaned it again. I also tightened the two jublie clips on the manifold T.

She now runs without the choke, although I still get a few misfires.
Thank you for all your help.

What is the ideal plug gap and what should the points gap be?

[sc3283]

.025 on plugs
.020 on points

[lakeeffectliving]

So, I am new here. I am looking for the carburetor for this same model. Does anyone have a part number for it? It is the keihin. Thank you in advance!

[CharleyL]

On an OMC engine the coils should be wired in series, not in parallel. Wiring them in parallel will burn the points up quickly. You may need to replace the ballast resistor or the capacitor in the timer. If the capacitor is bad you will see sparking of the points when trying to start it in the dark. The ballast resistor should have a resistance reading (about 40 ohms) when good and an open circuit when bad. It usually doesn't matter what the exact resistance is as long as it has a resistance and is not open.

Attached is the Keihin Carburetor exploded diagram and parts list. Only one model Keihin Carburetor was used on the 18 and 22 hp OMC engines. The marks on the parts list indicate which parts I ordered and replaced in my Keihin carburetor. It cost almost $100, but made a huge difference. My 1987 22 hp Truckster ran like new after replacing these parts in the carburetor.

Go to www.sillylittlecars.com, then go to the Manuals section. Then click on Maintenance Manuals. Select the 826767 Supplement manuall (the 826767 main manual is just part numbers by assembly with exploded view drawings of the body (non motor) parts for newer trucksters than yours, so it will not be very helpful. You want the Supplement. It contains all of the mechanical and electrical information needed to maintain and rebuild the 18 and 22 hp OMC engines. Both engines are the same, except for the cylinders and an advance spring in the timer. You can easily tell which engine you have because the 18 hp has the spark plugs located toward the bottom of the cylinders and the 22 hp engine has the spark plugs located toward the top of the cylinders. A single cylinder version of this engine was also made for one model of the Cushman scooters. Other brands of carburetors were used, but only one model of each.

Engine parts are available from several sources. Body parts are very difficult to find. Suspension, drive train, and steering parts are getting hard to find, but many, such as ball joints and brake parts are readily available. I found all of the brake parts that I needed from the local forklift service shop. When Cushmans were plentiful and in industrial use, the forklift shops maintained them.

Ball joints for my truckster were standard automotive parts, but the only cross reference to them was a visual comparison. Brake cylinder rebuilding kits were the same as early 70's Ford F-100 trucks. The wheel cylinders are almost the same as these Fords, but the outer shape is slightly different. Parts Direct and several other sources have the complete Cushman wheel cylinders for about $25 each, so it's not really worth trying to re-build them. My master cylinder and brake shoes came from the forklift shop for a price about 50% lower than through the internet.

The braking system in the Cushman trucksters uses DOT 3 brake fluid. But this brake fluid is alcohol based. It absorbs moisture like dry gas. When enough moisture has been absorbed, the brake system begins rusting from the inside out. Since the master cylinder reservoirs in trucksters is vented to the atmosphere, there is very little that can be done to keep moisture (humidity) from gradually getting into the brake system through the master cylinder reservoir vent due to natural temperature, humidity, and atmospheric pressure cycles. I couldn't find a new design sealed master cylinder that would fit in place of the original master cylinder, so I decided to just completely replace the brake fluid in my truckster every two years to keep the brake fluid from absorbing so much moisture that it can destroy my truckster brake system again.

If you have any other questions, just ask here. I try to check in here daily, but haven't been able to for the last couple of days. I hope I've helped, and it would be great if you could post your positive (I hope) progress here.


Charley

[dust1n_0414]

Charly, do are u still answering questions on the truckster? Im needing to know what the black/white and red/white wires by the coils go to. I have the diagram and it just shows a little box but cant figure out what that box goes to

[CharleyL]

Aranman,

The correct wiring for the coils is with them connected in series. If you wire them in parallel like you now have, the points will burn up quickly. Go to www.sillylittlecars.com. Then select "Manuals" and then "Shop Manuals". You will then have a list to choose from. Download the "826767 Supplement manual", an Acrobat .pdf file. It contains all of the motor information for the 2 cylinder OMC motors (both 18 and 22 hp). The electrical schematics for the engines and schematics for several models of Trucksters are in there as well. OMC motor parts are not easy to find but there are several sources for new parts, and even complete new engines. www.directparts.com and www.denniscarpentercushman.com are two of them. I also have some used parts from several 22 hp OMC motors that I'm selling off cheap, so I may be able to help with something that is not normally considered a "wear item" and not stocked by them.

Note the coil wiring in the schematic - it shows them wired in series with plus + of the first coil connected to the ignition key switch and the second coil minus - connected to the points with the condenser connected between the points and ground. Both spark plugs fire on every revolution, but one cylinder is on compression and one is on exhaust, so the one on exhaust doesn't do anything. A name given to this type ignition system is "lost spark ignition system" and it is very common in older small air cooled engines.

The only significant difference between these motors is the cylinders. The 18 hp cylinders have the spark plugs located below the center of the cylinder and the 22 hp cylinders have them located above center. Both the right and left cylinders and pistons are also identical and interchangeable. The timer advance spring may be different, but I've never been able to confirm this. Cushman/OMC also made a one cylinder version of this engine, intended for one of their later models of scooters. All of the parts of these engines, are pretty much interchangeable. OMC will not help you with information about these motors, even though they originally made them. Jacobsen.com has considerable documentation and manuals, so sometimes they might have documentation that you need as well. Both Jacobsen and OMC once owned Cushman. EZGO owns the Cushman name now, but everything with the Cushman name on it since they bought Cushman now looks like EZGO with the Cushman name on it.

Your running problems are most likely carburetor related. My 1987 Truckster had been sitting about 13 years and I had the carburetor apart and cleaned three times before I finally got it to work. I then bought many gaskets, needle valve, float, etc. and completely rebuilt my carburetor. Rebuilding it with new parts made a huge difference. The old mechanical fuel pumps also need to be replaced too. Unfortunately, these are nearly unobtainium now, and very expensive if you do find one, which if NOS is very likely to fail quickly due to the old rubber parts in them. I installed an electric fuel pump from OReily Auto Parts. It is pressure regulated, so the bypass fuel system and return to the tank is unnecessary, and my Truckster will usually start on the first revolution of the motor without using the choke now.

Be sure your fuel tank is clean and free of rust, then put a good filter between it and the fuel pump. If the tank is rusty inside, you can buy a tank cleaning and relining kit from KBS Coatings. This kit leaves an epoxy like coating on the entire inside of the tank. It will even fix pin hole leaks, and your old metal tank will be like new inside.

If you can find the model number plate, usually riveted onto the sheet metal to the left of the steering wheel, you will discover a 6 digit number, followed by a dash, and then 4 more digits, and maybe a few alpha characters following these numbers. The first two numbers following the dash are the year of manufacture. With an OMC engine, I'm guessing that your Truckster is about a 1968 or newer, but they went to a larger body design in the very early 70's. Dennis Carpenter has reproductions of the front sheet metal for your Truckster. The second two digits after the year may be the month of manufacture, but I haven't confirmed this. The 6 digits before the dash are the model number of the vehicle. These 6 digits are stamped in the sheet metal in several places in most trucksters. The easiest place to look for it is directly above the left front wheel in the trip piece over the wheel well. Unfortunately, the only place that has the full number with the year of manufacture is the plate to the left of the steering wheel.

3 wheel Cushman vehicles have VIN numbers and can be licensed as motorcycles in most States. The 4 wheel vehicles do not have VIN numbers, but most police departments consider them to be golf carts (over weight golf carts), and most of the States are now allowing golf carts to be driven on secondary roads with 35 mph or less posted speed limits if they have lights , rear view mirrors, seat belts, etc. without license plates or insurance, if driven by a driver who has a motor vehicle operator's license. Check your State's laws to see what is allowed where you are. Also check the community laws, since some communities are now requiring licenses for golf carts. Here in NC, it appears that these rules were a bit hastily created by someone who really didn't know much about golf carts and Trucksters, so the rules are a bit vague. Also look at the State rules for "Farm Vehicles". This is also a vague area of the law, which allows farmers to run almost anything on the secondary roads within the State. I now have the farmers "Slow Moving Vehicle" sign on the back of my Truckster, and flashing yellow lights front and rear. I haven't even been stopped yet. They usually smile and wave as they pass me. My Truckster has been as far as 22 miles from home, but usually it just helps me with yard maintenance (3+ acres).

Did I forget anything ? If so, don't hesitate to ask here. I try to check in at least every couple of days.

Please take the time to update your profile to show your name and approximate location. One of us might be just around the corner or in a neighboring town from you who can maybe be a good riding buddy or helping hand, if needed.

How about some better pictures? Maybe of your restoration progress? You can see my 1987 Truckster by searching for "Cushman Truckster Saved From The Forest" on this site, or early posts by me "CharleyL"

Charley

[aernest]

Thank you for the helpful information, Charley.

I recently picked up a 1972 Turf Truckster. It is a blessing that many of the parts are still available, although sometimes they are not inexpensive. So far I have totally rebuilt the brakes, rebuilt the transmission and am now about to get into the carb.

She runs and drives pretty well for an old, unloved vehicle.

[CharleyL]

I'm still here. Welcome to Buggies Gone Wild.

In your 72 Turf Truckster, you likely have the 2 cylinder 18 hp OMC horizontally opposed engine. Most of the OMC engines came with a Keihin carburetor. Earlier in this thread I posted the exploded view and Cushman parts list for these carburetors. If you look closely at the parts list, you will see some tick marks next to some of the parts. These are the parts that I replaced to get my carburetor working like new again.

With a carburetor this old, that hasn't likely been used in a very long time, you will need all of the gaskets and rubber parts, the float needle valve, plus a new float. I have found the passageway between the accelerator pump and the carburetor throat to be very plugged when I have rebuilt these carburetors for myself and friends. Make absolutely certain that you test the accelerator pump with a little gas in the float bowl before putting the carburator back on the engine, and take it back apart and clean it further if it doesn't work. It took me three tries to get mine clean enough to work, even though I had felt that I did a good job the first time. Floats, though expensive, need to be replaced because even the plastic ones will absorb fuel and sit lower, causing the float bowl to over fill. The parts for my carburetor cost me almost $100, definitely not cheap. The local forklift repair shop was able to get them for me. Wile working on the carburetor, carefully look inside the fuel inlet fitting of the carburetor for a tiny fuel filter and remove it with needle nose pliers. They are no longer available and will give you all kinds of grief if it is still there and plugged. Just make certain that you have a good fuel filter between the tank and carburetor.

Your fuel pump is likely history too. The rubber parts in it go bad, an original is almost unobtanium, and likely no good from sitting years on a shelf. They are also selling for several times what an electric fuel pump costs, if you do find one. An electric fuel pump from the auto parts store is an easy replacement and will work better than that old mechanical pump ever did, even when new. You won't need the bypass filter or the return line to the tank with an electric fuel pump either.


They also had an identical brake master cylinder on the shelf that they sold me for about 1/3 of what they sell for on the internet. Wheel cylinder rebuilding kits are identical to those sold for early 70's Ford F100 pickups, but the external shape of the Ford wheel cylinders is slightly different, making them not fit without grinding a bump off the casting.

Although it may not be a perfect match to your year Truckster, there is a lot of information that will help you in the two 898767 manuals. The supplement manual contains electrical and OMC motor information that will be very helpful. You can download .pdf files of these manuals from www.sillylittlecars.com . Go to "Manuals" from the front page and then "select the text regarding manuals" on the next screen. Then download free copies of the two 898767 manuals. The Supplement will likely do you the most good. The main manual is just exploded views and parts lists, likely not including your model. The electrical schematics may not include your model either, but very little changed from model to model and year to year, so most of what you need will be there. The 18 hp OMC engine has the spark plugs mounted below center on the cylinders. The 22 hp version has the spark plugs above center on the cylinders. So the cylinders are different for the two models, but the rest of the engine is identical with the possible exception of the advance spring in the timer. I have yet to verify this.

OMC also made a one cylinder version of this engine for a model of the Cushman Scooter and all of the parts for this motor are also identical, except for the crank case.

The hard to find parts are the sheet metal and other body parts. EBAY may be your only source for these. The mechanical and steering parts are pretty much all still available, and many are actually automotive OEM parts, but there are no cross references to aid in finding them. Still, an experienced parts man in an auto parts store can frequently look at the old part and find one like it on the shelf without using the cross reference.

Post a picture or few of your Truckster and I may be able to help more.

Also, please go to "User CP" in the left end of the second dark blue bar at the top of this page and enter some information about you and your Buggy(s). It will help us know how to better answer or help you with your problems.

Charley