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Kenh

Engine? vibration

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Kenh
I noticed last summer a vibration at1/2 to 2/3rds throttle. I'm running a 7116H with a Briggs. At first I thought it was a blade out of balance. Removed all three blades but all were well within balance,(almost perfect). Same shake with the deck not running. I know single cylinder engines will never balance perfectly, but could the vibration come from some place else? The drive shaft and fiberglass couplings look to be in good condition and all the bolts are tight. The angle gear drive is just a "tiny" bit loose on the input shaft, maybe about .010 to .015 play. Any ideas would be helpful. Thanks! Ken

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D-17_Dave
Besides what Roy mentioned, are the deck bearings in real good shape. If not, they could let the spindles wobble and rotate out of balance. This can also transmit vibration into the drive belt and run up to the tractor.

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MPH
If the same vibration is there with the deck not turning I'd say you should pull the driveshaft and check the discs and bolts. Not sure how long you have owned the tractor but it's simply ammazing what some folks will do to get a cheap patch job fix. Might just check first and make sure the washers on the drive shaft are evenly distributed, I recently forgot one on my B-112 I found while cleanning up. Input shaft to the BGB has a needle bearing, I won't claim to know if the play you have is in excess. How about play betwwen rotation of the driveshaft abd the output pulleies? If it has a S/G might loosen the belt after it's running and see if that make any dif.

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ehertzfeld
After mounting the diesel with rubber in between the engine mounts, I thought about putting some under the feet of a few of my tractors. I'm not sure if it will do any good or harm, but it seems like a good idea. My B1 and one of my 725's get very shaky at times. Elon

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Kenh
Dad gave me the tractor about a year ago. It has only been used to till the garden for 7 or 8 years prior to me having it. Deck bearings are good, BGB bolts as well as engine mounts are tight. Just had the engine out, removed the drive shaft in the process. All the discs and bolts look good. I think I'll try to check the runout of the drive shaft. It may be a bit out. I'll also check the BGB for any other problems. Has anybody used any other type of couplings for the drive shaft besides the fiberglass coublings. If the runout is excessive, I was thinking about a Lovejoy Jaw type coupling with the rubber isolators. http://www.lovejoy-inc.com/jawtypecouplings.htm The only real hitch is on the engine end of the driveshaft. Getting the coupling attache3d to the stub on the crank. Ken

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UCD
Are the driveshaft disc couplings installed right with the washers in the correct place and the rounded edge of the washers on the correct side.

CONNECTING DRIVE SHAFT 1. Under the tractor, slip a lock washer, and then a plain washer, flat face toward the screw head, on each of the two coupling cap screws (A, Figure 9). 2. Push a cap screw (A, Figure 9) through its hole in the coupling flexible element until it protrudes about 1/8 inch from the front face of the element. Slip a plain washer, flat face away from the element, on the protruding end of the screw. Slip a spacer sleeve between the washer and the mating boss on the flywheel. Push the cap screw through the sleeve to its mating hole in the flywheel, turning it to catch the threads. 3. Repeat step 2 for remaining cap screw. 4. Run both screws in finger tight, and then, using a wrench, tighten them permanently. Use another wrench on the crossbar (B, Figure 9) to prevent rotation. 5. See Figure 2. Depending on separation point used during engine removal, secure rear coupling (C, Figure 2) to drive shaft (B, Figure 2) or secure flange (E, Figure 2) to bevel gear shaft by tightening set screw

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Kenh
I have the early 7100 series. Didn't pay any attention to the washers when I took it apart, but did notice the round side when I put it back togeather. I put the flat side next to the cap screw head. It just seemed like the right thing to do. Thanks for the drawing. I'll double check that all is assembeled correctly. I beleive that you done as much as you can do and now the rest is up to me. I can see from my last reply that I need to proof read a bit better!!!!! Thanks Again. Ken

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UCD
Take the shaft out and check it for straightness. You can do this by rolling it on a flat surface. If you find a high spot strike the high spot with a heavy hammer. continue doing this until straight. I have done this to straighten a couple driveshaft's one was bent 45°. I got it straighter than the replacement from the factory

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