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My Bolens' Story and a carb problem

1011 Views 7 Replies 4 Participants Last post by  JamesC
First, I’d like to say thanks to everyone on these forums. I’ve learned a lot about my Bolens 1256-02 as well as others.
Second, some history behind my Bolens:
My grandfather purchased this tractor and attachments brand new in 1970 or 1971. For nearly 30 years, he used this tractor for tilling his large garden every spring, cutting the grass in his front and back yards every summer (until the flail mower was ‘killed’ by my father), collecting tree leaves and fallen limbs in the fall, and blowing snow during the winters of Colorado Springs. When I was big enough to hang on, I would ride around on the rear fenders while he was driving. When I go big enough to drive it, I was in the seat and behind the wheel. I grew up with this old girl. When Grandpa passed, my father took her to his house and used in the winters for blowing snow. She sat under a tarp most of the rest of the year.
A few years ago, my father decided to move out of his home in the country and into an apartment in the city. Those items that he did not want to take with him or could not take with him were split between my sister and brother-in-law and myself, sold, or taken for scrap. I wouldn’t let the old girl go to scrap or get sold. And I couldn’t trust my sister and brother-in-law with her. So, I loaded her up and brought her south.
Her new home is much dryer and warmer. She doesn’t have to move snow any more, and there’s no grass for her to cut (yet). I have a small flower garden that we use the tiller on once a year, and I use her to pull the utility trailer around for some of the yard work. Beyond that, she has an easy life right now.
My wife and I hope to move back to Colorado someday, so I’m keeping the snow blower for that. I’d like to find a deck mower someday. But for now, no need.
Here’s an issue I’m currently having – while she was with my father, something happened, and I don’t think the carb is set correctly. When I got her down here to New Mexico, I replaced the air filter and rebuild the Zenith 68 series carburetor. However, in order to keep her running smooth while working with her, I have to have the choke pull closed. This tells me the carb is set too lean. Using the instructions with the carb rebuild, I initially set the main jet to 1-1/4 out from seat. I also set the main idle 1 out from seat. She runs smooth at idle with no load. But as soon as I pull the throttle open enough to start working, she stalls out. But if I pull the choke closed, she fires right back up works just as she used to.
Our altitude in New Mexico is approximately 5500ft. Any input as to proper card adjustments for this altitude would be greatly appreciated.




1 - 8 of 8 Posts
Altitude would make your carb run richer, not leaner. You have another issue somewhere in the carb. Sounds like in the main circuit somewhere, given the good idle but dying out when power is called for.
What happens when you engage your pto with a attachment and motor at full speed ? but sounds like you need to rebuild your carb if it sat for a long time with fuel in the float bowl it would dry up and leave varnish that plugs jets.
That is a very clean looking tractor. Looks to be 100% original.
What happens when you engage your pto with a attachment and motor at full speed ? but sounds like you need to rebuild your carb if it sat for a long time with fuel in the float bowl it would dry up and leave varnish that plugs jets.
Thanks, ljohn. The carb was rebuilt when I got it down here to NM. However, the issue is still present. Because I have to use the choke, it sounds to me like the fuel mixture is still not right. With or without an attachment, the engine stalls out. If I use the choke along with the throttle, the engine goes to full RPM.
That is a very clean looking tractor. Looks to be 100% original.
Thanks, bolens_kid. With the exception of a couple small things (i.e. the petcock on the fuel tank, battery), it is completely original.
It does sound like you are running lean. First u need to richen the idle mix up if it is to lean the transition between the circuit will be off it will be readjusted later. Have your high end needle set 2 1/2 turns out from seated and low end should be about 1 1/2 out those are good starting points. Bring it up to full speed and adjust the high end out until the speed drops slightly then go to idle and adjust the same way but adjust for a smooth idle now run it back up as long as nothing is blocked it should transition just fine. I have been setting carbs in that way for 35 years works every time hope this helps and I agree nice tractor


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It does sound like you are running lean. First u need to richen the idle mix up if it is to lean the transition between the circuit will be off it will be readjusted later. Have your high end needle set 2 1/2 turns out from seated and low end should be about 1 1/2 out those are good starting points. Bring it up to full speed and adjust the high end out until the speed drops slightly then go to idle and adjust the same way but adjust for a smooth idle now run it back up as long as nothing is blocked it should transition just fine. I have been setting carbs in that way for 35 years works every time hope this helps and I agree nice tractor


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Thank, ljohn. I'll give that a shot. I called a local mechanic shop and bounced the info off the guy on the phone. He gave me a couple of things to look into also.

Thanks again!
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