Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

611 carb problem


littlemarv

Recommended Posts

After I restored my 611 I put the mower deck on it and put it to work. I always thought the engine wasn't turning fast enough but it mowed just fine. After the initial snowfall a week ago, I found that the snowblower definitely doesn't perform as it should. I finally got around to borrowing the phototach from work and checking into it. At wide open the engine is turning 2600 rpm. I think it should be going 3400.I tinkered with the governor arm- with the engine off (throttle wide open), I loosened the bolt and turned the governor shaft all the way to wide open. No change. I tried turning it the other way a hair, thinking that the same governor arm position would pull the throttle open a little further, thus more rpms. Fired up the engine, about 4000 rpm immediately. I found that the original setting is the only way the engine will run normally- any adjustment on that arm otherwise and the engine just screams.I also tried bending the linkage between the arm and the carb so it pulls the throttle open further- no dice as the governor arm travels that much less.I noticed the throttle shaft itself bounces a bit in the carb body. I put inward pressure on the shaft like this....

611 carb.jpg

I used the tip of a pliers so I know I'm not turning the shaft when I push on it.Runs about 3300 rpm (which is close enough for me). Let go and it drops back to 2600 or so. Did it several times, it works without fail.Anybody run into this? Any ideas?I'm guessing proper engine speed will greatly improve snowblower performance, as auger speed is everything.Thanks.

57e05747d64d5_611carb.jpg.2714a5c041bb45d123517a1dfdf8f2aa.jpg

Link to comment
Share on other sites

Yeh, I guess. It kinda sounded like you were on the right track. Sometimes there's the instructions in the manual, and then you find out what is really required. I attempted to fix my damaged brake band by proper adjustment, then I custom adjusted it - now I have a rattle. Now I can see my brake system exiting the tractor - except I found a genuine need for the park brake, when my tractor rolled off my trailer with me on it. That was exciting. But that's another story.

I don't know - maybe read it again for that one word you missed. It sounds like you are close with the gov thing - but the wording is strange in part of one of those posts. (the part where, it's the gov, it's the carb????) maybe. Sometimes the part that doesn't make sense is the key.

I haven't done it; just saved the info in case I have to. I save a lot of stuff like that.

I'm not clear on what you did to get the 4000 rpm - that's close; but too much of something. Maybe check the physical setup of the gov too - spring installed properly. (?)

Link to comment
Share on other sites

by throttle shaft bounceing, do you mean up down left right? or open closed.

I would guess if its up down left right, then the shaft and or bushings are worn and you are sucking in air there. By holding the shaft with the pliers, you are pushing the shaft in a bit, pushing the end against the houseing, effectively blocking the air so the engine sucks more gas.

Carb rebuild or new carb maybe.

I don't diagnose well without being hands on so just my opinion ;)

Link to comment
Share on other sites

You can increase engine speed by adjusting governor spring which is under the throttle plate. It is a bugger to get at. PM me your e-mail and I'll send you the sheet. More then likely you will have to loosen plate to get at it, make a spring adjustment and then re-assemble it and try it.

Link to comment
Share on other sites

rokon,

It bounces both ways a little. My thoughts were that if I bent the linkage it would make up for the open/closed slop, but then the governor arm moved just a touch less, so a net gain of zero. I straightened it back out.

I'm going to try adjusting the governor spring, if that doesnt pan out I think I'm going to try putting a rubber band on either side of the throttle shaft and put a little tension on the shaft just to see if the bouncing ceases and speed goes up.

Thanks for the input.

Link to comment
Share on other sites

I followed BLTs advice and now it runs 3450 rpm no load, and throws snow about 7 feet further! I have never used a single stage thrower before. They are a little tricky- you have to watch the snow coming out of the chute and adjust constantly to keep the auger full, but not plug it. When the snow coming out of the chute starts to dissipate, you either need to speed up or slow down and you've got a 50/50 chance on getting it right. One way is the glory of victory, the other way is shutting down and getting the :|| stick out to unplug the :||.

At any rate, it shouldn't matter anymore this year because now that my snowblower works, past experience dictates that it won't snow anymore....

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...