Partner continues to release saws that are better, stronger, faster. The K700 concrete saw is no exception. We purchased one as a replacement for a K650 that had sprouted legs. Like the rest of the Partner line, this concrete cutter uses oil-impregnated filtersto clean the air headed for combustion. While I like these filters quite a bit, as they can really pull dust out of the air, because there is no firm frame around these filters, I occasionally find that dust-laden air has found it’s way through a tiny ripple in the filter where it didn’t seat perfectly in it’s housing, forcing the accordian paper filter to do more than it’s share of work. But in general, air tends to enter the cylinder very clean and ready to burn.
The power-to-weight ratio of this saw is excellent. With 4.8 horses being generated from a machine that’s just over 20 pounds gives you lots of concrete cutting power in a very portable saw. While you can’t get this saw as close to structures parallel to the blade when trying to cut (i.e. close to a wall when cutting a floor), you can reverse the blade guard to get into tighter spaces. While it appears to work, I’ve heard from people that have done it that it throws the balance of the machine off, making cutting more difficult.
Speaking of balance, this saw has it. The placement of the handles relative to the blade makes this saw comfortable to use in most positions and keeps muscle strain to a minimum. This balance allows you to make more accurate cuts, as you can better control when the saw is dropped into a cut and where it’s cutting. This saw can be run wet or dry, and the included plumbing allows for easy adjustment of water flow.
If this had been a review of our 6-year old, 16″ K950, or even our little K650 that sprouted legs and walk away on us, this review might be a little different. The K950 has always packed a wallop and has been as durable as anything. The K650 saw a few years of daily use, and even ran for a day or so with a puncture in the air filtration system housing. In time the dust that was sucked in during that day caused some cylinder scoring and we started seeing some blow-by, but it was to be expected after that abuse. But I’m not reviewing those saws, I’m reviewing the newer K 700, which hasn’t had as stellar a track record as our previous Partner concrete saws. I’m not sure if I was simply lucky before or unlucky now, or if Partner has made some design changes that have resulted in a less-reliable saw. All I know is, I’ve had to pour an additional $500+ into repairs on a 2-year old saw, when I’ve never had to put more than $20 into parts for any of my saws (aside from filters, plugs and belts).
Our Partner K700 has become a saw that does not seem to like extended use in hot weather. If we’re going to be doing a lot of cutting and it’s hot out, I know we’ll need to bring additional saws, because at some point the K700 will just stop running, and will need a rest of anywhere from an hour to a day before it’ll start again.
We also had a problem with engine seizing. In defense of Partner, the mechanic who repaired our saw claims at some point the saw was run with unmixed fuel. That being said, we have a very small crew, and each man is trained in concrete saw fuel usage, mixing, etc. And the mix can has “Mix” is huge letters on it. In the 8+ years we’ve been running concrete saws, we’ve never had this fuel mix problem happen. So while it is a possibility that unmixed fuel was run in the saw, I’ve also heard from another Partner user who had an identical experience, and he was the only one using the saw, and the piston melted to the cylinder on the first tank of fuel.
We also had a near-miss with a sheared bolt that holds the entire air filtration unit to the saw. Again the mechanic blamed the operators, and again, this has never happened with any of our other saws, Partner or otherwise. I was using the saw one day and after about 40 minutes of use I noticed the housing for the air filters bobbing all over the place. After quickly shutting down the saw I could see that the single bolt holding the housing for the oil and paper filters had sheared where it met the say body, essentially allowing completely unfiltered air into the cylinder for combustion. The mechanic repairing the saw claimed the saw was likely mishandled or dropped, weakening the bolt, which then sheared under normal use. I concede this may be possible, but it just doesn’t seem very likely.
For the negative experiences I describe above, vibration transferred to the operator is minimal for this saw, making all-day cutting a breeze. However, the vibrations sometimes are too much for the saw itself, shaking loose bolts all over the saw. It’s gotten to the point where we have to carry around extra bolts, loctite and zip ties to keep the thing together when out on a job site.
Maybe I’ve had all these problems with our K700 concrete saw because Partner is trying to squeeze every last bit of power out of this tiny package and something has to give. Based on previous experience alone I would still recommend buying a Partner saw; they are light, powerful and easy to handle. But I would also compare it to other saws before writing the check.
Partner K 700 Active III Specs:
Power: 4.8 hp
Weight: 20.5 lbs
Fuel Capacity: 23.7 oz
Engine Speed: ? rpm (max spindle speed 5,400 rpm)
Arbor Size: 1 inch (25.4mm)