Abby’s Guide > Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) > Discussions > Inside an R-Tek engine
Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions |
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jrtrebor
Location: Michigan - 3 hours north of Chicago on the lake
Joined: Feb 10, 2010
Points: 539
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Inside an R-Tek engine
Original Message Feb 15, 2012 6:05 pm |
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Well I got the bolt stud welded, new old flywheel on, air gap set, good spark. Put everything else back on the engine. Still don't have the gov. vane so I just used the spring to keep the throttle at the idle position and used the idle screw to bump up the idle up a little. Put the engine back in the housing and it start on the third pull. Was idling and running well, then I heard a knock, couple seconds later heard another one then another one. So I shut it down. Was one of those sounds you know isn't good, kind of a deep sounding clank. It only made the sound maybe 3-4 times in about 20 maybe 30 seconds or run time. Pull the engine back out and decided to take it apart to check the rod cap. When I took the flywheel back off found that the new key I put in was sheared. ( could have had something to do with the knock) Was really clean inside. Intake port I believe Exhaust port. The two ports on the side run down into the crankcase. Which is up in the photo. Rod end on crank. You can see the roller bearings Rod cap was tight. Roller bearings in the cap. Most of them stayed in place when I lifted it off. I decided to put in the old crank I had from another R-Tek. Same part numbers. I put a few drops of oil on the crank journal so the bearings would stay in place. There is enough space for one more bearing, but that's all that came out. I guess once they all get spaced that's the way it should be. A few photos of the difference between the two cranks. Same part numbers. Top one is the older one out of a CCR2400 The ends of the counter weights are clipped off on the newer crank. (bottom photo) and the casting itself is a lot rougher. New crank on the left. If I remember to I'd like to weight them both. Just for comparison. Honda 11Hp crank on top. Key way slot on the replacement crank. Things were going well until I cracked a ring. Hate when that happens. There is an alignment pin in the piston ring groove for both rings. It keeps the end gap space of both of them aligned right above each other. Which normally you don't do. Unfortunately I didn't see the pins at first, pushed on the ring when it was on top of the pin not aligned in the end gap and.... snap.
This message was modified Feb 15, 2012 by jrtrebor
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trouts2
Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1328
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Re: Inside an R-Tek engine
Reply #7 Feb 16, 2012 9:01 am |
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Jrtrebor, Opened up my first two stroke a couple of months ago to get familiar with them and did snapped the ring in the same way not noticing the groove position hump.
I looked up all CCR models using the 141cc across a few years of each model run and all have drawings list the same 801220 crank. Your finding the physically different lob indicates that the drawings are not correct and for a model run there may be unaccounted for differences at lest with the online parts lists. Other than this mysterious crank it looks like Toro is getting it’s hp bumps from rpm bumps. For the HSK850 it gets a bit more fuzzy as many different makers used that engine from 4 to 7hp. There are a lot of pulley arrangements which cause crank bumps of the part numbers so hard track across engines. There is variation in the governor spring so overall it looks for Tecumseh HSK850’s the changes from 4-7hp are probably only rpm changes also with different governor springs. On the 141cc it looks like the vane and spring are the same from early 4hp 2400’s up to your 2010 6.5hp. They’re probably just spec’ing the governor spring arm to be bent for the rpm boost.
The rpm hp progression: R*Tec CCR2400 3950 4hp CCR2450 4050 4.5hp CCR3000 4150 6hp CCR3650 4250 6.5hp HSK850 CCR2400 3850 4hp CCR2500 3850 5hp SS722EC 3950 7hp (Ariens value but not a min-max like the others and probably +- 150 bringing the 7hp to possible 4200 which makes sense). In the past I thought that mufflers, carbs, possibly heads, ports, bores, pistons and rings were the cause of hp bumps. It’s looking like on the 141cc and 139cc engines over the years it’s basically adjusting the rpms for the boost.
It would be interesting to know just how much weight difference there was between your cranks. For a while I was weighting 8hp, 7hp and 5hp cranks on rebuilds. I found differences in similarly hp engines. Some differences were due to 3/4 vs 1 inch cranks but some were lob differences. The lighter cranks were in lesser maker engines (all Tecumseh) so I thought it might be do cost cutting but never sure.
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borat
Joined: Nov 10, 2007
Points: 2692
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Re: Inside an R-Tek engine
Reply #8 Feb 16, 2012 9:29 am |
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MNRunner:
I've been a motorhead all of my life. I've never charged anyone a cent for fixing something for them. I do it because, as JRT says, we enjoy the challenge of fixing something, especially at no cost to either myself or the owner. More often than not, I can. Occasionally money might be spent but judiciously. I recall fixing a non-starting snow blower for a friend's sister. It was a very old Craftsman from the early 70's not in the greatest shape. It was the first snow storm of the year. My buddy and I drove over to the sister's house and on the way, he was explaining to me that HE had recommended a "friend of the family" mechanic to go over the snow blower for her only a month or so earlier. So I fix it in a few minutes (dirt in float bowl and auger shear pins broken). As we were driving home, he told me that he was very disappointed that we had to fix the snow blower because his sister had just shelled out ........ $480.00 for repairs!!!! I was dumbfounded. I told him the machine isn't worth $150.00, why would she pay him that much to fix it? "Friend of the family", pay the bill. That's absolute b.s. If he were a friend, he wouldn't be sticking it to the guy's sister. Would he? And, it's not like she's got tons of money being a single mom working a low paying, menial job. It's rewarding to help people, usually friends and relatives, to save them a few bucks and often a lot of bucks. As we are all aware, 90% of stuff that doesn't work needs a very simple fix. Usually fuel related, which is often caused by negligence.
JRT:
I agree, that the ring retainer pins should be offset at least an inch or so. You'd think that having both joints in the same location would allow a bit of blow-by. Obviously hardly enough to matter. The pins on my Yamaha pistons are spread a good inch and a half apart.
It's hard to tell by looking at pictures but, that crank has to be defective. Spinning it up on a lathe should show imbalance. I'd also check it with a dial indicator to see if it's warped. I suspect that the new crank will solve the problem. Too bad about the broken ring. I hate when a $2.00 part holds up a project.
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RedOctobyr
Location: Lowell area, MA
Joined: Nov 5, 2011
Points: 282
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Re: Inside an R-Tek engine
Reply #9 Feb 16, 2012 9:46 am |
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Can you spin up a crank on a lathe to check for imbalance, though? I'd expect the crank, by itself, *should* not be balanced, since isn't it also trying to help reduce the imbalance due to the connecting rod and piston going back and forth? If the crank itself were balanced, then there's nothing to help counteract the conrod & piston. I would agree on using a dial indicator to check for runout, at least.
Now I'm curious- would you consider buying a new crank for the engine? If I could confirm that the crank is *definitely* bad, then I might consider that. But it also needs a flywheel. Barring some really cheap source for those, I will admit I, personally, might consider the engine too far gone (but I've also never had to do that kind of major surgery on an engine). Based on what I saw for Tecumseh crank pricing, a new one could be ~$70 or so, plus a flywheel, maybe at a similar price? I wouldn't pay those prices to try and resurrect it, unless I could be sure those would do it, and I could definitely sell the machine for more. But that's just me. Of course, a similar, inexpensive machine that got backed into, but still has a good engine, could be a nice source for parts.
Thus far I've primarily just fixed machines for me. Some for family. Not 'cause I'm unwilling to do it for friends, just haven't really been asked. I've fixed plenty of computers for friends & family. There is something fun about getting a device working properly again. And it's nice when it turns out to be just bad gas or something similarly straightforward.
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jrtrebor
Location: Michigan - 3 hours north of Chicago on the lake
Joined: Feb 10, 2010
Points: 539
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Re: Inside an R-Tek engine
Reply #10 Feb 16, 2012 10:02 am |
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trouts2 - I agree, Bumping up the RPM on these engines does seem to be the only difference I've been able to find that explains the increase in HP. And as borat's video clearly showed. Higher RPM does make a difference the blowers performance. Glad to hear I'm not the only one who has made the mistake with the ring. Bugs me when I do things like that, but sometimes that's how you learn. Trial and error. Don't mind the trials, don't like the errors.
borat - I always amazes me what some people end up paying for repairs. As you said most problems are fuel / carb. related and not a big deal. Other issues are simple part swap fixes. I love being able to fix things for someone and feel fortunate to have the knowledge and ability to be able to do so. Been working on all kinds of things for many years. Guess that is why I kind of enjoy trying to figuring out things like the problems with this engine. It's a challenge, unlike a lot of other no-brainer repairs.
I just ran across an ad on CL where a guy is selling his Toro 3650 because it needs a new flywheel. Hmmmm, Maybe there is a problem Toro isn't talking much about. Thought this was curious as well. Note: On page 32 of the R-tek engine manual, it states: " NOTE: Replace crankshaft and/or flywheel if keyway is distorted or cracked in any way."
I looked and the B&S engine manual link you posted (thank you). Read that the crank / rod needle bearing count is 33. You were close. I know, it's usually not the cost of the part it's the delay. Although the rings are going to cost me about $20.00 unless I can find a junk engine somewhere. Either way, it's money well spent if I can get things running correctly again, the blowers in great shape.
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jrtrebor
Location: Michigan - 3 hours north of Chicago on the lake
Joined: Feb 10, 2010
Points: 539
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Re: Inside an R-Tek engine
Reply #11 Feb 16, 2012 10:25 am |
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Now I'm curious- would you consider buying a new crank for the engine? If I could confirm that the crank is *definitely* bad, then I might consider that. But it also needs a flywheel. Barring some really cheap source for those,
Well actually I did have a crankshaft and flywheel from another R-Tek. It was in a CCR2400 that I parted out. I sold a few parts (carb, ign. coil) to get back what I had paid for the blower and make a little. Then kept the rest for spare parts. I don't do a whole lot of repairs on other people's blowers I mainly buy used blowers. Repair them for resale, or keep and upgrade / replace my personal use blowers. This 210R will be a big upgrade, it will replace my CCR2450. I'll be going from a 2001 model year blower to a 2010 model. I'll probably ask $200.00 for the 2450 but will take less (considering the lack of snow winter we've had). Only have $25.00 in the 2450 and a few hours time. I'll probably have about $65.00 total in the 210R barring any other problems. So doing the math, the 2010 Toro 210R will cost me nothing. And I'll have made $110.00 for the time I spent in both blowers.
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borat
Joined: Nov 10, 2007
Points: 2692
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Re: Inside an R-Tek engine
Reply #14 Feb 16, 2012 1:44 pm |
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"Can you spin up a crank on a lathe to check for imbalance, though? I'd expect the crank, by itself, *should* not be balanced, since isn't it also trying to help reduce the imbalance due to the connecting rod and piston going back and forth?" That makes sense. Turning the crank on the lathe to watch to see if the threaded end wobbles would be more productive. But then, so would a dial indicator. JRT: From page 23 of the manual: "If a new needle bearing set (32 needles) is being installed, the set will come on strip of paper and the needles will be coated with wax on one side. " Don't drive yourself nuts looking for no. 33.
This message was modified Feb 16, 2012 by borat
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RedOctobyr
Location: Lowell area, MA
Joined: Nov 5, 2011
Points: 282
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Re: Inside an R-Tek engine
Reply #15 Feb 16, 2012 1:59 pm |
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I have to say, it's always cool to get to see the inside of an engine that's been torn apart. I'm somewhat inspired. I have a 2-stroke weedwhacker that I'm hoping to replace with something better. It stopped running over the summer, seemed like a fuel delivery problem; I replaced the diaphragm in the carb, then it ran fine. Until the next time, and now it's tough to get running, or to keep running. It's just a cheap machine (was free to me), missing the guard, whose main redeeming quality was that it ran. Now it doesn't even have that Really don't have the desire to spend a bunch of time to try and get it back on its feet, so perhaps I'll open the engine up instead. That would be interesting. I've never gone deeper into an engine than taking the head off (well, except for a tiny nitro-powered R/C engine which blew a conrod, and had surgery to install a new one). I'm always impressed when someone just dives deep into an engine (even better when the rest of us also get to see pics). It's one of those things I've just never had to do, so I've never tried it.
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