1650 vs. 1450 QL comparison

[Mike McKown]

3 1650's, 2 1450's and one 1250 here.

The 1250 was the smoothest by quite a bit followed by the 1450's. The 1650's shake noticeably more than the 1450's.

All of the above tractors had the mounts replaced years ago with the CC parts.

[Darrell]

My 1650 does shake somewhat , shakes the worst at idle. Raising the idle speed will help. Mid/Full throttle is not to bad , but i still feel a slight vibration sitting in the seat. Supertuning your engine and checking out your driveline for worn parts helps ALOT.

Alot of the hood rattling can be fixed by taking your time to loosen/adjust some parts. I unbolt the grill enough so it can move around , loosen the firewall ( the metal plate bolted to the dash/shield for fuel tank ?? ) and adjust. Bend the metal prongs on the firewall and hood for a tight fit , this helps ALOT.

On top of the firewall/tank shield is either two flat pieces of metal or two angle pieces that you can slit some vacuum hose and glue it on or get some square rubber pieces and glue it on the angle pieces. Like what some newer newer QL's and the 82 series has glued on seat mounting plate.

Replacing the rubber that goes around the fuel tank stand helps alot also , but it is like $50 from Cub , and i haven't tried to find a good replacement , yet.

WHEW !! Tighten everything back down and hope it is good !! But you will probably have to do some fine tuning.

[bkw3614]

I can't speak for a 1650, but I replaced the ISO mounts on my 1250 last year. I used Cub Cadet mounts. First, I started with the recommended torque, as listed in the instructions packed with the mount kit. and it didn't look right. So I used the 1 1/2 threads showing method, and the vibration was terrible.

I checked the bolts, and they were loose in the mounting hole, so I began to tighten each with a quarter turn at a time to try to find the spot where the vibration would improve. I then went a little farther and found a higher vibration point and backed off the nuts to the place where the vibration was felt the least.

I don't know if this will work on your tractor, and I have nothing scientific to back this, but it worked for me.

[IH Cub Cadet]

My 1650 is still in pieces, but it came with a 14 hp engine, but I have a rebuildable 16 hp for it - whew!!!!

From what I read, the 16 hp Kohler K341 vibrates quite a bit. As you go down in hp, the vibration goes away.

I think you can "tune" your isolators my changing the torque on your bolts from loose to tighter and see how it runs. Also give the isolators some time to "wear-in" - if there is such a term.

I think the QL tractors had a very high idle setting due to potential vibration, don't recall what that is.

Also, did you do a cradle mod before you installed your new isolators? If so, that might help.

[sawdustdad]

Thanks for all the responses and feedback. I did do the cradle/rail mod. I think I'll track down the source of the rattles on the 1650 as much as possible, and run it this summer. It will get grass cutting duty this year, so we'll see how it runs.

I wonder if the installation of new flex joint disks on the 1650 (being stiffer initially) would contribute to vibration, while the well-worn disks on the 1450 absorb some of the misalignment and don't transmit it to the hydro and frame.

Perhaps as the flex disks wear in, the vibration will decrease? Thoughts on this theory?

[bkw3614]

PHP Code:

I wonder if the installation of new flex joint disks on the 1650 (being stiffer initially) would contribute to vibration, while the well-worn disks on the 1450 absorb some of the misalignment and don't transmit it to the hydro and frame.

Perhaps as the flex disks wear in, the vibration will decrease? Thoughts on this theory? 


It's possible. What you could do is to loosen the bolts on the flanges on each end of the drive shaft, start the engine, and let it run for a few minutes, then stop the engine and tighten everything, being careful not to move anything in the tightening process. This will align the drive shaft to both the engine and the charge pump. While the engine is running, you can check to see that the drive shaft isn't bent by holding a flat screwdriver with a square shaft against the frame, with the screwdriver tip on the drive shaft to see how much it bounces. If it bounces a lot, your drive shaft may be bent and you will need to have a new one made. I would recommend that a machine shop make it, using 4140 steel shaft material. The machine shop can be sure that it is perfectly straight when it leaves the shop.

I doubt that the drive shaft is the problem, or the flex discs are contributing too much to the vibration problem. I still think your ISO mounts need a bit of fine tuning in tightness, and have the engine timing and carburetor set properly. With any one cylinder engine, there will be vibration because there isn't anything to neutralize the natural motion that it sets forth as it runs. Hence, the balance gears that the older Kohlers had. Your 1650 doesn't have balance gears, or it shouldn't have. Personally, I am glad the grenade gears are gone. I don't know why Kohler took them out for the Quietline series, but I am told they aren't there. Thus, we have to live with some vibration.

I did use some felt in some key places to curb some vibration, especially at the place where the hood meets the lower grill housing, next to the hinge. I also used some rubber bumpers on the fiberglass dash where the hood meets it. It didn't stop any vibration, but curbed a lot of noise.

It is going to take some trial and error to come up with a combination of fixes to suit your liking. It takes some time. Do a little bit at a time and not more than one single fix per try. You'll find the right combination of fixes. Good luck, and remember there are a lot more people here that have answers.

[bluesman]

I keep hearing about the balance gears not being in the K341. Is that true or just a rumor? I'd like to think that I won't have to take my engine apart just to remove them.

[Cub-N-It]

Originally Posted by bluesman

I keep hearing about the balance gears not being in the K341. Is that true or just a rumor? I'd like to think that I won't have to take my engine apart just to remove them.

Mine did not have balance gears.
Also I did not mention this. I don't have a 1450 but I do have a JD 140H3 with a K-321 14hp. The crank position is the same as the 1650. The JD engine has less vibration than the CC1650.
I'm thinking the general consensus would be the K-341 vibrates the most, followed by the K-321, followed by the K-301 being the smoothest.
Would everyone agree?

[CADplans]

Originally Posted by Cub-N-It

Mine did not have balance gears.
Also I did not mention this. I don't have a 1450 but I do have a JD 140H3 with a K-321 14hp. The crank position is the same as the 1650. The JD engine has less vibration than the CC1650.
I'm thinking the general consensus would be the K-341 vibrates the most, followed by the K-321, followed by the K-301 being the smoothest.
Would everyone agree?

Oh, the 10HP is a smoothie!!

[sawdustdad]

Here's an update on the 1450 vs. 1650 vibration issue. I got my 1450 back together with cradle mod and new IH iso mounts. Tune up, etc. Started her up and it shook like crazy...for about 5 minutes. Then it settled down and smoothed out quite a bit. The engine was not running rough, it was running perfect--about 3500 rpm by laser tach. After another 20 minutes of use, it was even smoother. So, I went and got the 1650 out and started to cut the grass. Hadn't been run more than 5 minutes since the cradle mod and iso mounts. Of course it ran smoother than I remember, and as I cut the grass, it settled down even more. Again, running about 3600 rpm by laser tach.

By the end of the day, both tractors seem similar in vibration and noise. I tracked down some rattles on the 1650 and fixed them (mostly hood related).

I am thinking that the high vibration is due to new flex discs and/or iso mounts wearing in. What a difference a half hour makes.

I'm a happy camper again!