Cushman 22hp throttle barely opens

[Nairod]

First post. It's a 22 hp 4 wheel cushman, has a Walbro carb. I am restoring it from a history of considerable abuse and neglect, it was going to be scrapped.

I am a VW guy, thought this would be easy. Hah.

The gas pedal will fully actuate the gas pedal linkage back to the carb.

It is not directly connected to the throttle butterfly or anything else; instead it regulates the movement of an arm going to the base of the timer. This arm also does not connect to the throttle, it seems just to follow and be captured by the motion of the gas pedal linkage.

Connected to the timer arm is a smaller arm that pivots. It has a return spring attached to the timer arm on one end and a ball joint on the other.

Attached to the ball joint is an adjustable spring loaded link that attaches to the throttle butterfly linkage.

So, near as I can tell, there is no direct connection between the gas pedal and the throttle.

With the pedal fully depressed, and the timer arm allowed to move fully forward, the linkage arm to the carb throttle will only open about 1/3. It seems like the little return spring may be too weak as there doesn't seem to be much drag.

Anyway, I don't understand the intention of all these linkages, and am not sure how to get this thing to have some power.

Thanks if you can help!

[CharleyL]

Nairod,

Welcome to BGW. If you would, please go to "User CP" in the left end of the second dark blue line at the top of this screen and tell us more about yourself and your Truckster. A first or nickname would help. There are quite a few Cushman owners here, so I expect others to provide you with answers and help too.

That is the mechanical governor mechanism. These engines don't hold up well when run at higher than 3600 rpm. Unfortunately, there isn't a whole lot of information available for making these governors work well, and I doubt that they ever did. The one in my Truckster had been crippled long before I became the owner and I haven't succeeded in getting it working, so I just have to be careful not to over rev the motor.

If you go to the www.sillylittlecars.com website and click on "manuals", then "shop and maintenance manuals" in the text, you will find several manuals for Cushman. The 826767 Supplement contains the OMC motor information for both the 18 and 22 hp motors and electrical diagrams for many of the Truckster models made in the 70's and 80's that used the OMC motors. The 826767 main manual only contains exploded views and parts lists, of which most of the parts are no longer available.

You can still buy parts for the drive train, steering, brakes, and motor, but the sheet metal, etc. is no longer available. If you are willing to pay the price, you can still even buy a brand new short block OMC motor. www.directparts.com and www.denniscarpentercushman are the two sources for motor parts. Dennis Carpenter specializes in selling scooter parts, but one scooter model used a 1 cylinder version of the OMC motor, so they carry the motor parts, and they will fit the 2 cylinder motors too. www.directparts.com has brake and steering parts, and parts for the drive train, but they likely only have the parts that wear out. I found that steering knuckles, brake lines, etc. are automotive parts available through auto parts stores, but unfortunately there is no cross reference to them. You will need to take the old part in and hopefully find a guy behind the counter who has been in the business for a long time, who can recognize the part that you brought in and then find the equivalent on the shelf for you.

Forklift repair shops once serviced these vehicles, so they may still have parts on the shelf for them too. I was able to buy a NOS brake master cylinder from my local forklift shop and the flexible brake line to the front axle from O'Riley Auto Parts. The brake line was for a 1968 Dodge van. Early 1970's Ford F100 pickups used brake wheel cylinders like the ones in these Cushmans, so the cylinder rebuilding kits for them work perfectly, but the Ford cylinder casting has a bump on the outside of the casting that needs to be ground off if you want to use it. I was able to get Cushman brake cylinders and shoes form the forklift supply.

Jacobsen once owned Cushman. Although they don't seem to be able to help with parts, their manual library is quite extensive, and might be able to help if you need more than available through www.sillylittlecars.com. Go to http://www.jacobsen.com/americas-contact-us/ and make a request.

Your model number should be on a metal plate located to the left of the steering wheel. It will be a 6 digit number, possibly with an addition of a following letter, then a dash, followed by 4 more digits. The two digits following the dash are the year of manufacture. You can also find the 6 digit model number stamped in the sheet metal in several locations, but the easiest to find is in the sheet metal fender just above the left front wheel. Unfortunately, none of these other locations include the dash or the numbers that follow the dash.

If you can, please post some photos of your Truckster. It also sometimes helps to add photos if you have a question, so we can better understand your question. "Go advanced" below is where you start when adding photos. Then just follow the instructions to upload and attach photos to your post message.

Charley

[jclark138]

Welcome !

[Nairod]

Thanks for answering, guys!

I will see about pictures. I'm not much of a computer guy, so far I suck at getting pictures to upload properly.

There is a tag to the right of the steering column. 898444-8110.

Below it are stamped 945 and 1000.

CharleyL, how did you manage to get your Cushman to run without the governor? I am tempted to just run a cable to the throttle.

Spark advance is independent of the governor? I could run it with a throttle cable and be good? For sure I recognize that over revving it is a bad idea, but right now it won't go up even a very minor grade.

I think this may have been for industrial use, maybe inside factories... it has a cab, but no headlights and a compact, somewhat rounded front end.

[CharleyL]

My governor was bypassed when I got it. I played with it some, trying to figure out how it was supposed to work, but then just put it back the way that it was. It's been several years since I've even looked at it, so give a few days and I'll try to re-learn what I discovered about it and I'll take some photos for you. My slate is quite full right now so it will likely be a few days before I'll get the chance. There is a section of the manual that I told you about that has a description of the governor and some detailed pictures of the governor pieces inside the timer. Take the time to find and download that manual. There is a lot of good information in it, especially about the OMC motors, that you will find very useful.

My Truckster is 4 wheeled, has headlights but they were low beam only, until I rewired them and added a hi - lo switch (but not a foot switch). It has a full fiberglass cab with doors. Do a search for "Cushman Truckster saved from the forest" and you should find a few photos of it, or just search for some of my early posts under "CharleyL" .

Your model number seems to show that it was built in 1981. They made several models at a time and quite often custom built for customers, taking a standard model and then making it fit the customer's needs. The same model design was thus made over several years, rather than existing in production for only one year. Different differentials determined the top speed at full rpm and there was a dual range differential, mostly for the on/off road needs. The Turf Trucksters mostly had these, but my Truckster has the operating lever, although it isn't connected to anything, and my differential is not a dual range. I wish it was.

The cab and front of my Truckster looks something like a little version of a long haul semi and it has a flat front. I know of later models that had the curved front, but again, both shapes could have been made at the same time.

Charley