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Post by bigmac on Aug 2, 2020 19:37:05 GMT -5
Just 50 miles shy of 10,000 and my front wheel bearings go. I can feel a slight wobble when riding and can feel and hear the rim shake around separate from the axle when I try to wiggle it.
I've watched several how-to videos on youtube about removing and installing wheel bearings. Looks easy enough but when I try to hammer out the old bearings, they won't budge. I also tried expanding the metal slightly with a heat gun. Maybe I need more heat and should try a blowtorch instead as shown in one of the videos I've watched?
Any suggestions? I'm trying to avoid buying special tools. I got a completely trashed Chinese scooter for free that I use as a parts bike and its front axle has a 12mm head whereas my running scooter has a 14mm so being a bit smaller in diameter, I've been using the axle from my parts scooter as a drift/punch to knock out the bearings. It makes good contact. However, this size difference concerns me because even if I manage to get the old bearings out, I then have to worry about finding proper fitting ones to replace them with as these scooters clearly don't all have the same size front axles.
I replaced the crankshaft last fall and thought that'd be the hardest job this thing could ever need but now I'm unable to simply pop-out the wheel bearings.
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Post by bigmac on Jul 4, 2018 11:47:58 GMT -5
I got my new rocker arms from a seller whom I've ordered from before as he appears to know about these things and even points out that there are 64mm and 69mm versions in his listings.
It was brutally hot and I was sweating profusely while working but I got it all together. Everything seems to be good after its first few uses. Hopefully no more oil leaking nor cracked rocker arm / camshaft holder.
That kind of has me freaked out now. I feel like at any moment, some part of the engine is going to crack and blow apart while I'm miles from home.
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Post by bigmac on Jun 27, 2018 21:19:39 GMT -5
I'm so glad that gasket did not seal well. I ended up buying another one from a different seller but when I removed the cover to install it, I noticed this:  Had I not taken the cover off and saw that, things could've gone really badly. I don't know how long that crack was there but it couldn't have been too long since it was only about a month ago when I last had the cover off. I'm sure I would've noticed it then unless it was really small and has since grown. The new gasket I got fits perfectly all the way around the groove so it's defiantly the right part. I swear the part I got on my first order wasn't even made for this bike. But now I need a rocker arm / camshaft holder before I can confirm the leak is gone. |
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Post by bigmac on Jun 23, 2018 11:29:02 GMT -5
FAIL.
It started leaking oil a few days ago. The rear body panels needs to come off to excess the cylinder head cover and I want to wash it before taking it apart as it's as dirty as a well used dirt bike at this time. It's going to take me about a week to do something about it.
Frustrates me so much how they basically throw some random thing in a package and send it to you as your replacement part.
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Post by bigmac on May 3, 2018 14:43:39 GMT -5
I lucked out with the Permatex. I didn't have any on hand nor wanted to buy a tube of it for this extremely small project. Luckily, a relative of mine bought a tube of Permatex for a car repair and didn't need the rest, which was still about half a tube full, so I got it yesterday while visiting.
I cut the extra length off, put a drop of Permatex on and brought the two ends together. That was done today and the package says to give it 24 hours to cure, so I should be ready to get my scooter back together tomorrow.
If it doesn't seal well, I'll try some of the other suggestions mentioned here.
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Post by bigmac on May 1, 2018 19:35:11 GMT -5
The vendor I bought from is 1800coolparts on ebay. www.ebay.com/itm/182197797450When I told the seller of my problem and the possibility that it may have been for a 150cc gy6, I got a reply saying he sells no other seals. I checked the seller's ebay store myself and found no other cylinder head cover seals aside for the one I bought. Who knows what happened. Maybe the seller got a seal for a 150cc gy6 or some other engine in what was suppose to be a shipment of just 50cc seals and I got the mixed up one. I've gotten 150cc parts instead of 50cc parts several times from ebay sellers so it's always the first thing I suspect when something doesn't fit. I had thought about adjusting it by removing the extra length but wasn't sure if it was a good idea but since you guys mentioned it, I think I'll try it. The seller said I could return it, so I'll be fully committed to getting this to work if I try to modify it. |
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Post by bigmac on May 1, 2018 11:21:29 GMT -5
I used 15w-40 oil but started using 10w-30 conventional after doing a top end rebuild and then switched to 10w-30 full synthetic after the break-in period for that rebuild. I had a minor oil leak issue with my cylinder head cover even before the rebuild but finally decided to replace the gasket seal that goes around the cover after noticing it leaking more with the lighter oil. Being super duper careful to make sure I got the right part, I removed the seal and held it up to my computer monitor to make sure what I was ordering online looked identical to what I had in my hand and that its description said it was indeed for a gy6 50cc scooter engine. After all that, I get the part and find that it's too big to fit in the groove along the edges of the cover. Here's a picture to show what I'm talking about:  I don't get it. I thought maybe it was for a 150cc gy6 but the seller claims to not even have 150cc cylinder head cover gaskets available. Are there multiple versions of 50cc cylinder head covers? I know there are two types of cylinder heads for the 50cc gy6 and I've had both and used the same cylinder head cover on both. Now I need to figure out if it's worth the trouble to send back this $3.55 part or forget about the lost money and if I should attempt to buy another one from a different seller or just continue using my old seal and just deal with any oil leakage because Chinese scooter parts are too difficult to replace. |
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Post by bigmac on Oct 14, 2017 21:07:53 GMT -5
I'll have to remember that if I ever need to replace the crankshaft and decide to go through the trouble of doing it.
I think the baffles in my muffler are falling apart and are even making weird noises as exhaust gasses are pushed through. Forgot what they're called, but there are these instruments which are basically hollow wooden pipes with rice or something similar to rice in them and you tilt them side-to-side to play them. I heard they're commonly used in rain dances to simulate the sound of falling rain. Well, my exhaust can be played like one of those instruments. Just tilt it side-to-side and listen to the soothing sounds of loose pieces of baffles moving from one side to the other.
I'm kind of worried about running into different versions if I order a new one though. Either the bolt holes won't lineup or the exhaust pipe will not meetup with the cylinder head port.
The noise is annoying enough that I'd like to get it replaced soon but it's not too bad compared to the noise I just fixed. That noise always made me think something was rubbing against my back tire. In fact, that's what I thought at first. There is a small plastic fender mounted just behind the cooling fan cover and I thought it had come loose and was making contact with the tire when I first heard it.
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Post by bigmac on Oct 9, 2017 15:45:56 GMT -5
I guess I'll need to replace my variator if I want to find out if doing so would make it quieter since the difference in condition is like night and day between the one I have and the one you had. I have a gy6 service manual that includes all the maximum allowable wear limits of parts but I'd need a micrometer to know if my variator and the sleeve it slides on are at or beyond them.
That issue you mentioned about the "v" guides is a pet peeve I have with these Chinese scooters. I want replacement parts that, well, you know, replace the worn-out ones. Not entirely sure what the deal is. I assume I'm getting copies of copies of copies and minor spec changes occurred somewhere down the line. I buy a part and get some 3rd generation Chinese copy of it which isn't quite the same as the original anymore. I sometimes wonder if that's why there are two different cylinder heads for the same engine.
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Post by bigmac on Oct 6, 2017 23:47:37 GMT -5
Yeah, hopefully it'll be problem free for quite some time. Thanks for the help.
One question though. When the hole in the center of your variator got worn enough to wobble on the bushing, did it make any noise and if so what did it sound like?
As I said, I checked mine but it didn't appear loose enough to get any real wobbling going on. It fits over the bushing plenty loose enough to slide side-to-side without hindrance but maybe it's slightly too loose and could have a slight wobble. That's the thing though, I never felt what a brand new variator and slide bushing feel like together so maybe it's suppose to fit tighter than mine and I wouldn't know. Just like the "v" guides. I thought mine were okay until I got the new ones and noticed the difference.
What I find interesting about the "v" guides is that the old and new ones actually look identical until you check the grooves on their outer edges. The grooves are so deep on the old ones that when slid onto the retainer, they barely stay on whereas the grooves on the new ones are just deep enough to fit the retainer, making them stay on very tightly.
Not sure if all the wear normally occurs inside the outer grooves of the "v" guides but if not, maybe that's how mine managed to create a noise like the one in the video.
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Post by bigmac on Oct 6, 2017 19:06:09 GMT -5
The noise is gone.
However, I still think I'm hearing some noise that wasn't there before. Maybe I'm just being overly alert now and think I'm hearing stuff that's actually normal. It's kind of like a low rumble sound.
I'd like to replace the variator and its slide bushing to see if that would make it quieter but can't stand the thought of doing anymore work on it at this time. The riding season is nearly over so perhaps in spring I'll get that done.
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Post by bigmac on Oct 5, 2017 19:46:11 GMT -5
Those plastic "v" slider guide things came yesterday. I got them installed today but didn't have time to put it back together to see if the noise is gone.
Kind of a let down to hear that you haven't heard any noises before like the one in the video from a variator issue. The new "v" guides do fit much more securely to the retainer and hold it nicely within the variator compared to before. I checked for slack that could cause wobbling between the variator and that slide bushing but didn't feel any.
Hopefully tomorrow I'll get it back together and find that it's finally fixed after all this. I really don't want to have to order any more parts just to discover that they didn't fix the problem after installing them.
We're going to need another drum roll.
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Post by bigmac on Sept 30, 2017 22:15:19 GMT -5
The variator looked fine so I kept it on.
The belt and roller weights were replaced since I could tell for sure they had wear on them. Later, while running the engine without the belt, I noticed the noise seemed to be either gone or just barely there (couldn't tell for sure over the normal engine sounds) so I replaced the clutch.
The video I posted at the start of this thread about diagnosing gy6 engine noises said those plastic guides can break, causing abnormal noise but mine appeared intact. So they are in there making a dampener between the two parts but perhaps some looseness has formed and it's enough to create noise.
I must say though, I'm so glad this whole situation pushed me into doing that top end rebuild. I never thought I'd get my Chinese scooter to run so well. One push of the start button and it comes right on and idles great. I haven't had it stall out on me once at any stops while out on the road. Aside for the annoying noise, of course, this thing is running better than it did when I got it, about 6 years ago.
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Post by bigmac on Sept 30, 2017 11:37:12 GMT -5
It has gone 200 miles since the top end rebuild. I've been giving it a hard break-in and the noise isn't any worse. I'm starting to doubt it is the crankshaft after all. I also rechecked the shaft's ends for slack but felt none.
I find the noise is rarely heard at low idle speeds, such as around 1,500 rpm. Perhaps that's why the guy who uploaded the video of an engine noise like mine kept revving since it's mostly heard at higher speeds.
Two possibilities I have in mind now are either:
1: One or more of those three plastic V shaped guides that go onto the retainer plate behind the variator are too loose and are wiggling around between the retainer plate and variator.
2: The slots for the roller weights on the variator are worn along their edges so the rollers can shake around inside there more than they're suppose to.
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Post by bigmac on Sept 18, 2017 18:42:11 GMT -5
Guess that's what happened then with the kick start that time. The spring's force seems fairly strong so the possibility that a lack of grease and/or dirt buildup could stop it from returning seemed unlikely to me.
As of now, I plan to wait and see how bad the noise gets with time. If it starts getting much noisier, I'll once again check for slack in the bearings. Perhaps I'll soon install that starter clutch that I was too late to cancel the order of and check for slack while I have the CVT cover off.
I'm still wondering why the noise seemed to be almost completely gone when I removed the drive belt. The tightness of the belt would put pressure on the shaft's left side. Assuming it's the crank bearings, are the bearings less noisy without the belt because there is less pressure on the bearings?
I was also thinking, that video I posted with a 50cc gy6 making the same noise as mine after a crankshaft replacement might still have damaged bearings. I have watched several videos about installing cranks on gy6 engines and the guy in the video always talks about cooling the shaft and heating the half of the case it fits into, otherwise it'll be too tight of a fit and forcing it in can damage the bearings which is said to be a common mistake. Maybe that's what happened in that video I posted.
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