12Hp AS vs, 12hp AQS power & smoothness wise?

Mon May 07, 2012 8:37 am

I used the misses 1200 cc i restored for her to mow the first two times so far. I have a 122cc with a new replacement 12hp AS kolher engine in it and the 12HP AQS (quietline) in the 1200ss. I just noticed when mowing with the throttle in the upper RPM area this 12hp AQS(wide frame) is so much smoother over the 12HP AS 122 engine(narrow frame). Not only is it smoother there is hardley any vibration too. The misses is going to love this machine when she takes over some of the mowing. My point is was the 12hp aqs redesigned or something changed inside it?

Re: 12Hp AS vs, 12hp AQS power & smoothness wise?

Mon May 07, 2012 12:32 pm

Blocks are basically the same. The AQS has compression release at low RPMs, but that would not affect wide open throttle. A lot of folks take out the balancing gears/weights when they're building/rebuilding Kohler engines, so depending on who had their hands in your 12-AS engine, it may not have the balancers in it. Also, the quietline cadets use an ISO mounted engine, where the engine bolts to a set of rubber engine/motor mounts, then bolts to the frame. That takes a whole lot of the shake and vibration out of the engine, and does quiet them down a bit. They also used a much larger muffler, combined with the engine side panels, really quiets down the engine. I think that the engines all vibrate the same, and most folks with the quietline's will tell you that if the motor mounts wear out, and you direct-bolt the engine to the frame (like in the older cadets), they'll rattle your teeth too.

Also keep in mind, your 122 has a narrow, straight frame, that's basically a set of C channels. The wide-frame cadets have a hydro-formed frame that is wider, heavier, and stronger than the old narrow frames, and was designed to handle the load of the 14 and 16-hp engines, and was later used for the 17, 18 gas, and 17-hp diesel engines. So, all that extra strength and weight will certainly dissipate much more vibration from the engine.

Re: 12Hp AS vs, 12hp AQS power & smoothness wise?

Tue May 08, 2012 2:07 pm

This was a Cub cadet 1000 that i let my son get his feet wet with his first ground up restoration. I had him install all new iso pads and disc brakes. While gathering parts I found an AQS 12hp too. Being in a rush while the kid ws helping me i just put it 12hp AQS for now figuring i'd refresh a 14hp that i have too and swap them out. I find that the 12hp is running great and cuts with power even in the tall grass she trucks right thru it. I also like my 122cc too with its new replacemnent 12hp (factory new replacement big $$). In comparing the two the smoothness goes to the 1200. Now my plans are to install and rewire the 14hp AQS into the cc108. I purchased the 148 decals for it too. I like the narrow frames and the wide frames.

These machines live on like the car in the movie christine. I have an orginal cub cadet 100 with the creeper. the PO ran the snots out of it snowblowing his long driveway in the winter. She blows a puff of blue smoke on the cold start up but calms down when it gets hot. Being so old she makes noises(rod knock possibly) when she is tilling. But she stays running. Every year i pull her out, fire her up, till the garden in the spring and fall then put he to sleep and wake her up in the spring and repeat. She's been here for over 6 years+ now. I did put on some good rubber sneakers(tires). But i have to say i keep the oil filled(never have to add any since i use 30wt non det) and seafoam in the gas. But what a machine that runs great in this condition. She refuses to go to the bone yard.

Re: 12Hp AS vs, 12hp AQS power & smoothness wise?

Sat Jul 21, 2012 10:56 am

AQS engines weren't the only ones with compression release, all engines Cub Cadet used before them had it, except maby the k-161 and k-181 had it. If your 122 has a replacement engine it most likly has ballence gears also.

Re: 12Hp AS vs, 12hp AQS power & smoothness wise?

Mon Aug 20, 2012 11:09 am

My 122 has the replacement 12hp as engine. She appears like it was changed not too long ago and she still runs like new. Thats why i paid the seller what he wanted($400) these new replacemet engines weren't cheap.