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Post by JerryScript on Jan 8, 2016 20:08:21 GMT -5
Not to argue rockynv, but I'm confused at your concerns. The crankshaft and rod handle the force of thousands of explosions per minute, each of which is much more powerful than any impact wrench. I would be interested in reading some examples of people who have messed up their variator or crankshaft with an impact wrench, it could prove enlightening. Yes the crank and rod handle explosions but under constant pressure lubrication or splash lubrication that is renewed with every splash of the dipper in the oil pan which on a 4 stroke with dipper splash lubrication is twice before then next ignition pulse. The better splash systems use a paddle wheel that provides a more constant flow of lubrication. When using an impact wrench you squeeze the oil out of the crank and rod bearings after the first few moments and then start scuffing things. You can mute it by holding the variator from vibrating and transfering the impacts to the crank however a novice is not usually going to do that and just let it wail. Its not going to be a 100% failure rate and could be all over the scale depending on whose pulling the trigger on the impact wrench and the characteristics of the impact wrench itself. On a GY6 having more torque than in impact wrench I am not so sure of that. We are only talking about engine developing around 8 hp and a relatively few pounds of torque while my main impact wrench on the other hand creates around 650 pounds of torque with even the bargain units developing over 100 lbs to remove lug nuts. Better safe than sorry and use the correct tool for the job following established best practice. Thanks for the explanation. I have never rotated the crank more than a turn or two when using an impact wrench on the variator nut, it only takes a couple of whacks to tighten up, so i don't think lubrication is an issue. Perhaps I'm wrong, but I've been using it on two 50cc with BBKs for three years now, and my stock 150 for the past year, maybe I've just been lucky. If you happen to have a link to a discussion where someone did have issues, I would love to read more about it! |
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Post by geh3333 on Jan 8, 2016 20:35:43 GMT -5
This is what I am talking about. My 8 amp electric impact does not even turn the crank a quarter turn . because I hold the variator with my hand . drive face that is. You must know what you are doing when using certain tools.
I highly doubt "all " the oil will be shaken off the bearings in 2 seconds of using an impact. Also the oil pump is pumping oil when the crank rotates forward. Either way , the variator should always be held in place even with an impact. Its very easy to do if you hold the drive face with you free hand, then no spinning.
If somehow the variator spins then I agree with jerry , its not enough to cause any bearing issue.
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Post by rockynv on Jan 9, 2016 1:44:17 GMT -5
You read on this and other boards of folks who went at it for a long time with an impact wrench and could not get the variator or clutch nut loose because of various reasons some even burning out the ones that run off battery power. This is not best practice and if a failure happens a few thousand miles later or more immediately most will just chalk it up to faulty engine parts, bad design, etc. Some instead of holding the variator will stuff items down the spark plug hole having the con rod and crank taking the full brunt of things.
Yes you can many/some/a few times get the nuts off without damaging the crank and such but you won't always since you can also damage things and really won't know unless you pull things apart and do the forensics. Shop manuals tell you to use the proper tools and while some mechanics who have been trained otherwise will bend the rules and use impact wrenches on moving parts the only time you should really use an impact wrench on a moving part is with caution removing wheels from cars, trucks and trailers. Putting things on to moving parts with an impact wrench should be only to wheels using a torque limiter stick on the impact wrench however a set of those is relatively expensive and they can be inconsistent.
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Post by JerryScript on Jan 9, 2016 10:25:56 GMT -5
You read on this and other boards of folks who went at it for a long time with an impact wrench and could not get the variator or clutch nut loose because of various reasons some even burning out the ones that run off battery power. This is not best practice and if a failure happens a few thousand miles later or more immediately most will just chalk it up to faulty engine parts, bad design, etc. Some instead of holding the variator will stuff items down the spark plug hole having the con rod and crank taking the full brunt of things. Yes you can many/some/a few times get the nuts off without damaging the crank and such but you won't always since you can also damage things and really won't know unless you pull things apart and do the forensics. Shop manuals tell you to use the proper tools and while some mechanics who have been trained otherwise will bend the rules and use impact wrenches on moving parts the only time you should really use an impact wrench on a moving part is with caution removing wheels from cars, trucks and trailers. Putting things on to moving parts with an impact wrench should be only to wheels using a torque limiter stick on the impact wrench however a set of those is relatively expensive and they can be inconsistent. I guess my search-fu is weak, I tried finding examples here of what you are saying, but I couldn't. I'll try searching other boards as well, maybe I'll get lucky. If you could point me to any example discussions, it would be appreciated. |
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Post by rockynv on Jan 9, 2016 10:58:45 GMT -5
You read on this and other boards of folks who went at it for a long time with an impact wrench and could not get the variator or clutch nut loose because of various reasons some even burning out the ones that run off battery power. This is not best practice and if a failure happens a few thousand miles later or more immediately most will just chalk it up to faulty engine parts, bad design, etc. Some instead of holding the variator will stuff items down the spark plug hole having the con rod and crank taking the full brunt of things. Yes you can many/some/a few times get the nuts off without damaging the crank and such but you won't always since you can also damage things and really won't know unless you pull things apart and do the forensics. Shop manuals tell you to use the proper tools and while some mechanics who have been trained otherwise will bend the rules and use impact wrenches on moving parts the only time you should really use an impact wrench on a moving part is with caution removing wheels from cars, trucks and trailers. Putting things on to moving parts with an impact wrench should be only to wheels using a torque limiter stick on the impact wrench however a set of those is relatively expensive and they can be inconsistent. I guess my search-fu is weak, I tried finding examples here of what you are saying, but I couldn't. I'll try searching other boards as well, maybe I'll get lucky. If you could point me to any example discussions, it would be appreciated. They don't realize what they have done so you won't get a hit searching on "I broke my variator using an impact wrench when I should have used the proper holding tool and hand wrench" yet you see the posts about somehow the end of my crank came off, my drive face got wobbly, the piece of garbage bike threw the rod, etc. You see the bikes on Craigs List for sale needing work and when you go see them the threaded end of the crank that holds the variator on is broken off and although you can see the scuffing and annealing from the impact wrench on the nut few will ever admit that they used one. There is a reason the OEM service manuals don't advise one to use an impact wrench when servicing a variator or clutch and always recommend using the holding tool and a hand wrench. You will see discussion by trade mechanics admitting that they took a chance because they got frustrated since some joker previously used an impact wrench on a bike and that they had to do the same to get the bike apart so they could repair the damage the other guy had done and then using all new fasteners reassembled it using a torque wrench to OEM specs. |
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Post by JerryScript on Jan 9, 2016 11:07:28 GMT -5
I think I understand now. What you are describing is improper use of an impact wrench, not damage due to choice of tools. Stripped threads can be caused by improper use of any tool, and I wholeheartedly agree that improper use of an impact wrench will do more damage faster. Thanks for the clarification! One thing I have noticed is that the drive face gears are very strong. When my impact broke last week, I tried using a monkey wrench to hold the drive face gear teeth. I didn't even scuff the gear teeth, but the monkey wrench got several scrapes as a result. I would definitely recommend the variator removal tool that screws into the CVT bolt holes with teeth aligned to the drive face gear teeth, they are cheap and easy to use. However, one still must use proper care to prevent stripping or cross-threading the crank end threads with any tool.  |
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Post by geh3333 on Jan 10, 2016 17:32:00 GMT -5
I think I understand now. What you are describing is improper use of an impact wrench, not damage due to choice of tools. Stripped threads can be caused by improper use of any tool, and I wholeheartedly agree that improper use of an impact wrench will do more damage faster. Thanks for the clarification! One thing I have noticed is that the drive face gears are very strong. When my impact broke last week, I tried using a monkey wrench to hold the drive face gear teeth. I didn't even scuff the gear teeth, but the monkey wrench got several scrapes as a result. I would definitely recommend the variator removal tool that screws into the CVT bolt holes with teeth aligned to the drive face gear teeth, they are cheap and easy to use. However, one still must use proper care to prevent stripping or cross-threading the crank end threads with any tool. Your right jerry, that's what I was saying also . you have to know how to use the tools at hand on the task at hand. My 8 amp impact is massive for using on a variator nut ,but if you use it wisely it works just the same , and It works on my car also so I don't need 2 different impacts. The only thing is I cannot use it for a roadside fix , but in the past 4+ years , I never needed one anyway. |
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Post by geh3333 on Jan 11, 2016 15:46:46 GMT -5
I should add that I wasn't implying " rock" does not know how to use certain tools. Just that the ones tearing up the CVT and whatnot does not know how to .
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Post by rockynv on Jan 17, 2016 9:41:58 GMT -5
I should add that I wasn't implying " rock" does not know how to use certain tools. Just that the ones tearing up the CVT and whatnot does not know how to . Even if you do "know" you are more likely to do damage using an impact wench on a crankshaft especially on a small engine. The correct tools can be had for less money than an impact wrench and are usually easier to carry. Even if you do use an impact wrench to get the parts off you still need a locking device and torque wrench to put it all back together to spec. When making a recommendation to a crowd you are usually best giving the safe one that has the greatest chance of success. When servicing inside the CVT case the best practice is to use locking tools and a torque wrench. When you watch a factory trained scooter mechanic demonstrate a belt change even though they do have air tools in their shops they most always leave them on the shelf. Sometimes they will use the air tools only for removing fasteners however will still use the locking tools with the air tool and will put everything back together with only hand tools using a torque wrench for tightening the critical fasteners. Maybe I am a bit more critical on this because I was head of maintenance and responsible for enforcing best practice in the factories I was in charge of however its still the best practice and will prevent problems down the road. |
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Post by geh3333 on Jan 18, 2016 12:13:27 GMT -5
I guess when I comes to someone who has used impacts for many years, it is common knowledge that its easy to strip threads with them , but that doesn't keep us from using them "because we know how to use them". ever since I bought my scoot , I had all the older wiser members tell me to buy an impact for the variator and clutch nut . i guess its hard for me to tell others to use tools that I do not like to use, especially when there is an easier way .
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Post by rockynv on Jan 20, 2016 13:24:22 GMT -5
Off with a holding fixture and impact wrench is ok but on is still a manual process. Are there some things that I will risk personally after 50 years experience that I won't reccommend to a newbie, yes but its with full awareness of the risk and what could happen if I slip up. In forum I will only reccommend the low risk methods
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Post by phatboy on Jan 23, 2016 3:47:39 GMT -5
I should add that I wasn't implying " rock" does not know how to use certain tools. Just that the ones tearing up the CVT and whatnot does not know how to . Even if you do "know" you are more likely to do damage using an impact wench on a crankshaft especially on a small engine. The correct tools can be had for less money than an impact wrench and are usually easier to carry. Even if you do use an impact wrench to get the parts off you still need a locking device and torque wrench to put it all back together to spec. When making a recommendation to a crowd you are usually best giving the safe one that has the greatest chance of success. When servicing inside the CVT case the best practice is to use locking tools and a torque wrench. When you watch a factory trained scooter mechanic demonstrate a belt change even though they do have air tools in their shops they most always leave them on the shelf. Sometimes they will use the air tools only for removing fasteners however will still use the locking tools with the air tool and will put everything back together with only hand tools using a torque wrench for tightening the critical fasteners. Maybe I am a bit more critical on this because I was head of maintenance and responsible for enforcing best practice in the factories I was in charge of however its still the best practice and will prevent problems down the road. To be fair, piaggo has a special tool for holding the variator in place on Vespas. It makes it very easy and straightforward. I dont think such a special tool exists for all chinese scooters that is anywhere near as good as the vespa tool. I have one of these Vespa variator tools (an aftermarket version) and it was not all that cheap, but I think you'd have to be insane to use air tools on a vespa, with what they cost. On the other hand, chinese scooters are cheap to buy, cheap to mod, cheap to fix. I don't know if a mechanic will bother taking the extra time to do the best practices on one of these, and in a way I dont blame him. A typical vespa owner pronbably wouldn't hesitate paying $300 for simple roller and belt change, and chinese scooter owners probably don't want to sink that kind of money into their scoots. I admit that maybe I haven't always done the kind of best practices on my chinese scoots (that I would always do on my Vespa, I am meticulously careful with that.) |
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Post by rockynv on Jan 23, 2016 10:30:30 GMT -5
The complete Buzetti kit for the Vespa/Piaggio/Aprilia 250 is less than $50 and the tools for doing the work on a Chinese scooter are pretty much universal costing even less and work well enough.
I have had both and just kept the Aprilia since wrenching on the Lance was cutting down on riding time.
I can honestly say now that in almost 5 years of near to daily riding year round on the Aprilia that it has used much less fuel and cost me overall much less to maintain (belts, oil changes, valve adjustments, head replacements [multiple], clutch, variator, bearings, muffler, ignition, etc failures on the Lance) than it did owning the Lance for a year. Aside from normal belt, roller and tire changes every 12,000 miles and oil changes every 6,000 miles its been 30,000 trouble free miles without a single breakdown. Oh I did finally have to buy a new battery last month and the last time I checked the valves they did not need any adjustment making it so they have been checked twice so far and only needed adjusting once.
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Post by steve on Jan 26, 2016 16:59:40 GMT -5
My impact wrench doesn't turn my variator. I hate rapping my knuckles with wrenches.....
I use an impact to take my CVT apart. There are not specialty tools for 50cc variators. They don't have the screw holes like 150's.
I tried for 2 hours one day to change my belt without an impact.
I went and bought a compressor that day. I hope I am forgiven.
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Post by phatboy on Jan 26, 2016 19:00:12 GMT -5
Personally I see nothing wrong with *loosening* a variator nut with an impact even if you have the "right" tools.
Isn't it only tighening that we should try not to do?
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