Abby’s Guide > Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) > Discussions > Boratified MTD 5.5hp 21inch HSK850
Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions |
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trouts2
Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1328
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Boratified MTD 5.5hp 21inch HSK850
Original Message Jan 28, 2012 1:06 pm |
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The results of Borats Craftman seem pretty good even in comparison to the newer Toro's with 141cc engines and curved paddles runing stock rpm. I gave up on MTD straight paddles a few years ago so stopped buying them. BUT given the good showing of Borats machine decided to give an HSK850 a fling for which a cheap MTD or Murray is a good candidate. This morning I picked up an MTD 5.5 in excellent shape, (mostly) for $100. The body is excellent, no rust no scratches but the inside of the bucked has the paint scrapped. The guys 3 car lot was sand and gravel with mounds and holes. It's electric start, 4-5 years old but only used for two seasons due the owners heart condition. It came with a line cord and for some reason three brand new belts, a bottle of Sta-Bil and a gallon and a half can of gas half full. His son gave it to him with a bottle of Sta-Bil which he thought was the mix required. He only ran it with Sta-Bil, no oil and from what he tells me only ran about slightly less than a gallon of gas through it since he got it. He claimed that one can of gas half full he gave me was the only fuel he ever bought for it. It fired up on the first pull and seemed to run strong so I ignored the no oil part and bought it. It gets 95psi compression on three rope pulls and 115 on electric start so seems ok. Borat, I'd like to compare the flat paddle section of this one to yours. If you can please measure your mid-paddle section flats. What's the L and W of one section and what's the distance front to back? The MTD is (2) 1 3/4 x 4 1/4 sections and the front to back span is 8 1/4. If they match then the MTD should compare your Murray with booted RPM. I've got an excellent condition Toro 3650 I'm using this year so have a good machine to compare with.
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borat
Joined: Nov 10, 2007
Points: 2692
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #9 Jan 29, 2012 10:09 am |
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For some reason, the information that I've been gathering leave me a bit unsettled regarding the comparative heat ranges. The information on chart, although published by Champion is quite a bit different than proposed cross-equivalent plugs between NGK and Champion. Three heat ranges difference "7" on the chart and "4" on the recommended NGK plug doesn't appeal very well to my logic. Regardless, as per my edited message above, I've come to the conclusion the the RCJ8Y is likely cool/hot enough to work well in the HSK850. I've got several hours of hard work on my Craftsman with no signs of problems. It just keeps on keeping on. The only time it slows down or stops is when it runs out of fuel. edit... An NGK 6 makes much more sense. Why some vendors recommend the NGK 4 is beyond me unless the actual heat variance between a 4 and a 6 is not that great operationally. Regardless, I'm satisfied enough not to bother pulling the Craftsman apart. When the temperatures warm up, I still think I'll make an access door in the cover to make spark plug maintenance easier.
This message was modified Jan 29, 2012 by borat
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trouts2
Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1328
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #10 Jan 29, 2012 12:35 pm |
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RedOctobyr: a mystery hole in the back, facing the operator Often there’s an empty opening for models sold without optional electric start. RedOctobyr: I can't just pop it on to quickly check the RPM' Last year 4 machines were setup with wires on the plugs running to the handlebars. That end had a quick connect and the mate on a short wire on the RPM meter. It worked out OK for static readings but underway snowblowing the machines are changing speeds rapidly. The small variations in load cause the RP M meter to re-compute which takes a few seconds and it presents fuzzy readings until the machine gets more stable. I was looking monitor engine sagging and that usually happened too fast and unsteady for the meter’s response time. That was on two stages which are much more stable than single stage machines. On the riding mower things are more stable and the meters readout well but for those a few readings with a vibratech and you know what’s going on so a fixed meter there is not so worth the effort. boratify- (v) to enhance the performance and value of an engine for very little money, by increasing RPM's, esp. by means of a string on the governor. Usage- "My snowthrower was OK, but kind of underpowered. But then I boratified it, and now it's awesome!" Great definition. Can that expand? To borat…..When borating…..When finally borated….. Borat and RedOctobyr: I had poked around last week because the dealer sold me a Honda BR4HS and my machines call for 6 and 8’s. ?? Not sure why but I’m going to get the spec’d plugs. For all the reading I did what I’ve come up with on plugs is use what’s spec’d unless there’s a consistent plug condition that indicates going up or down would help. My asking about plug temp was for overall chamber temp. It looks like the dissipation on a plug is so local that it won’t have any effect on the chamber. So that’s out. For raised temps getting lowered by running a cooler plug. ?? All I got from looking into that was confused. Getting to know for sure requires equipment and test procedures I can’t do. The only view into this is probably noting when the engine explodes, melts or throws a rod. Better than that would be as you suggest, monitor the plug occasionally. That’s easy, telling enough and probably all that’s required. An interesting point Borat made was that some OPE that scream and use 6 and 8’s at least by Champion charts. Using an 8 in a pushed HSK850 will probably be fine. In some of the heat range stuff they talk about fitting a plug into a 500 to 800 degree range. The heat ranges are big and broad so picking a plug you don’t really know about other than by 4, 6 or 8 indicating a temp range you don’t know for internal temps you don’t know is too much to deal with. I give up. The result of all that whatever is knowable by pulling the plug and having a look. If something is suspected and another range might help then the charts are somewhat helpful for a ball-parking another range. After mucking with the boratified machines 4000 seems like slow motion.
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RedOctobyr
Location: Lowell area, MA
Joined: Nov 5, 2011
Points: 282
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #12 Jan 29, 2012 2:05 pm |
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trouts2, excellent points: - You're probably right on the mystery hole on my machine. Mine does not have electric start, but it was an option. That must be what the hole's for, thanks. - Tachs: I'll admit I'm not quite sure what the connector that you're talking about is for. But my Tiny Tach type device has 2 wires, one that you ground to the engine, and a wire that you wrap around the spark plug wire. You reminded me of something I'd been thinking about before, along the lines of what you described. Perhaps I could wrap another wire around the plug wire, and run that out to somewhere accessible. Then, to check the RPM's, I might be able to wrap the tach wire around *that* one. I don't know if that would work, however, since the tach would not actually be wrapped around the plug wire. - Definitions: The dangerous verb would be to over-boratify. Something along the lines of "I boratified my machine to 6000 and I loved it. So I decided to try for 9000, and over-boratified it. Now I have a hole in the block" Kids, boratifying is done by trained professionals in a controlled environment, and should not be attempted without adult supervision. boratifying involves risk, past performance is not necessarily indicative of future results; may cause dry mouth, sweaty palms, envious neighbors, and childlike glee as the snow flies further than it ever has before. Consult a medical professional if symptoms persist more than 4 hours. borat, that's a good question. Realistically, the higher RPM's will increase the wear on the engine (higher inertial loads), add to vibration, possibly start to take their toll on motor mounts, cause more wear on the belt as it engages, use more gas, more noise, etc. My manual makes note that the brake must be adjusted to stop the paddles within 5 seconds or something. The higher speeds would increase the time it takes for everything to stop. These are at least some of the "theoretical" drawbacks, I couldn't say whether any of them are actually significant (eg- maybe the lifespan of the engine goes from 800 hours to 700 hours, and no one will ever care). And I'm willing to replace a belt more often if it means much better performance, gas usage is very small anyhow, etc, so many of us might be OK with those tradeoffs. But then again the people here tend to be more of "enthusiasts" vs the general public. It's certainly an interesting question as to whether they avoided adding a throttle to try and stay away from cannibalizing 2-stage sales. One argument could be that an appeal of a SS is its simplicity and lack of controls. So it's friendly to use. Do these 2 things to start it, then just squeeze this handle. Less intimidating than the multiple levers and handles on my 2-stage, I suppose. Add a throttle, and you start to get away from that slightly. You'd have to set the throttle such that the default was a normal snow-blowing speed, and you could also squeeze it to rev even faster. You couldn't do it like a chainsaw, where no throttle input means very little happens. Actually, as I type this, I think I saw someone make mention of an old (60's-70's?) machine their family owned which had kind of an "extra power" button or lever. You used that, and you'd get a little more out of the engine. It might have been on a SS, I don't recall. So perhaps some company did try something along those lines?
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trouts2
Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1328
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #13 Jan 29, 2012 4:07 pm |
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>>>Perhaps I could wrap another wire around the plug wire, and run that out to somewhere accessible. That's it. I got lengths of hookup wire 6 feet long. One end of that wire wrapped around the plug. The other end ran up the handlebars. A simllar wire was run from ground to the handlebars. The tack wires got the mating connectors. The tach could be detached and moved from machine to machine. The tach did not get mounted perminantly. Each time it was just put on the machine dash, plugged in and taped down. Four machines were setup that way so one tach could be moved around. I had a few tachs and some machines got "perminant" mounts and others connect wires only. I did not like leaving the tach out all winter. Vanilla hookup wire is not shielded and engines can generate electrical noise of many frequencies that could interfere with the plug signals. I also tried some Belden shielded signal wire which was very small like 20 but it did not improve response time. What you need is a nice warm afternoon, open up the SS and install the wire. Give the wire around the plug 4-5 tight wraps and electrical tape over that. Then run it up the handlebars. The harder part is planting the gauge where it will stay, not vibrate off and be easily removable. One possibility is to get some thin aluminum plate about the size of the gauge and form it to an L with foot of the L part just larger than the thickness of the gauge. Drill a hole in the L foot and another through the handlebars at the side. Bolt on the L and epoxy velcro on the tall section of the L and the back of the gauge.
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borat
Joined: Nov 10, 2007
Points: 2692
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #14 Jan 29, 2012 5:05 pm |
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I put a Tach lead on my Toro machine as well while I had the cover off. Way too much work removing the cover to not do it. I didn't leave a wire on the Craftsman or MTD because it's not all that important once the lower rpm is set. It's not much more than an idle on those two. On the Toro however, being set at a fixed rpm is where the machine works. Hence the necessity to ensure it's set right. I made a couple wraps around the spark plug lead then used a small tie wrap to keep it there. See pic below. No sure why the picture is so big. I resized it to 400 x400???? Took the picture out. It was screwing up Trout's post. One thing that I wanted to re-iterate is the point of ensuring the oil ratio is changed to deal with the added load on the engine. I've always been a believer in using a bit more oil than less. Two cycles are hard working engines and have scant amounts of lubrication running through them. Despite the fact that lower oil to fuel ratios will work, you can rest assured that a bit more oil will enhance performance and durability. Particularly when the engine is being run beyond the normal parameters of the engine's operation. Not that I'm all that worried about the engine's durability. Four thousand rpm, in my opinion is not much more than a lively idle for any decent two cycle engine. I believe the HSK850 is designed and built well enough to handle far more than the 4000 rpm lope of a snow blower.
This message was modified Jan 29, 2012 by borat
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longboat
Joined: Feb 11, 2009
Points: 103
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #15 Jan 30, 2012 10:01 am |
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... One argument could be that an appeal of a SS is its simplicity and lack of controls. So it's friendly to use. Do these 2 things to start it, then just squeeze this handle. Less intimidating than the multiple levers and handles on my 2-stage, I suppose. Add a throttle, and you start to get away from that slightly. You'd have to set the throttle such that the default was a normal snow-blowing speed, and you could also squeeze it to rev even faster. You couldn't do it like a chainsaw, where no throttle input means very little happens. ...
I think you hit the nail on the head there. Mfrs. are always looking for ways to dumb down their products - saves them many phone calls/rma's from idiots trying to figure out how/when to operate throttles, etc. The other issue is, I would guess, emissions regulations. I think even OPE is regulated somewhat, and probably even more in the near future, and that is why throttles are locked on most new OPE. The mfr. can reduce emissions significantly if they allow the engine to run at only one speed. They can also maximize fuel efficiency for that one engine speed, and that helps out their emissions issues, too.
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RedOctobyr
Location: Lowell area, MA
Joined: Nov 5, 2011
Points: 282
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #17 Jan 30, 2012 11:08 am |
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The other issue is, I would guess, emissions regulations. I think even OPE is regulated somewhat, and probably even more in the near future, and that is why throttles are locked on most new OPE. The mfr. can reduce emissions significantly if they allow the engine to run at only one speed. They can also maximize fuel efficiency for that one engine speed, and that helps out their emissions issues, too. Good point. OPE is definitely regulated already, and has been for probably ~10 years, hence no mixture screw adjustments on most carbs nowadays. God forbid you are able to adjust your machine so it runs right And I'd forgotten about another throttle->no throttle scenario. Mowers from the 80's, let's say, had throttles, at least many of the 3.5hp Briggs-powered ones I remember. But my Craftsman walk-behind, which is probably about 15 years old, has no throttle or choke, just a primer button. My Lawn Boy was the same way (well, I think maybe it had a two position control tucked away down by the air filter, but I always ran at the faster position). I don't know if good machines have throttles now; I want to say many do not. I guess we should be glad our 2-stage snowblowers still have throttles. Enjoy that while it lasts.
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borat
Joined: Nov 10, 2007
Points: 2692
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Re: Boratified MTD 5.5hp 21inch HSK850
Reply #18 Jan 30, 2012 12:18 pm |
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Around these parts, SS machines are a rarity.
Last year and this year, I was/am vigilantly watching ads for used SS machines on Kijiji. Only four machines were listed last year. One was a Toro CCR2000/3000, can't remember which, nonetheless, the woman selling it was asking a ridiculous price so I passed on it and bought an brand new Toro 221 QE for only a hundred or so more than what she was asking. There was a Honda HS35 in great shape for sale for a reasonable price but the four stroke engine put me off. The other two I bought.
This year there are thirty or forty dual stage machines (mostly Craftsman/MTD/AYP) products listed. Occasionally, you'll see a nice old Ariens or Toro dual stage but that's infrequent. Around here, SS machines simply aren't appreciated. Initially, I didn't even know SS machines existed up until about five years ago (when I joined this forum). Nonetheless, after becoming aware of their existence, I had the same view of them as being inadequate for our conditions. I had never seen one in action so I didn't know any better. Even when I picked up the old Craftsman, I was far from impressed with it's performance. I'd rate it at about 10% better than a shovel. It was truly lame but I knew there was potential in the two cycle engine and for the price, if it blew up, so be it. I was buying it just to experiment with anyway.
After a bit of work fixing the engine mount, over-riding the governor and putting on a new belt, it's been doing yeoman service since. It sees more work than any other machine I have for several reasons. First of all, it's much more fun to use, works great, handles all but the worst storms and lastly, I want to see how long it will hold up being run well beyond the machine's stock settings. I'm certain that it has at least ten to fifteen hours hard labour on it by now. Time will tell but so far, I couldn't ask for more.
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