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Post by paydem on Apr 7, 2019 10:43:41 GMT -5
Update:
I recently rebuilt the engine. The bearings that were in the engine was SKF C4. When I bought new bearings (same SKF C4's), I noticed that the clearance (and free play) were the same on all of the bearings (old and new). When I reassembled everything, the free play in the crankshaft was still there. Other people who use these bearings told me it's completely okay, as it's designed to withstand higher temperatures (mainly for mid-race or high-end engines).
Conclusion: The old bearings weren't in the best condition but I could have used them for some more time. It didn't upset me too much as I needed to change the crankshaft aswell.
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Post by paydem on Feb 10, 2019 8:16:20 GMT -5
Hard to tell from the videos. If you can move the crankshaft side to side, up and down then your bearings are going bad. Personally, I would not replace the bearings without replacing the crank and variator at the same time. If funds are low, and you do not mind splitting cases, you could just replace the bearings, seals, and possibly the ramp plate. If the variator moves out of balance because of worn splines on the old crank, your new bearings may not last long. The variator has 1000km's on it. The ramp plate has good teeth too. I guess I won't need to replace it if I replace bearings and the crankshaft?
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Post by paydem on Feb 10, 2019 7:32:20 GMT -5
I always had buzzing sound from the CVT and thought it was the starter motor or variator. Video with everything removed: youtu.be/FLS5sg9-hm0Video with the variator removed: (only variator's back plate, bushing, primary pulley) youtu.be/Ca5aWOD3pCQMy crankshaft isn't great neither. The splines are pretty worn out and variator's back plate seems to have some slack (doesn't seem to have the slack when I tighten up the variator nut, though). I know it would be perfect to replace bearings as well as the crankshaft, but what would you do in this situation? My budget is pretty strict. Would you replace the bearings only? Here's the photo of the crankshaft:
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Post by paydem on Feb 5, 2019 5:00:14 GMT -5
I'll be buying CHT gauge for my Minarelli 70cc AC engine. I wonder, at what temperature should I stop and turn off the engine? Sorry if this was posted earlier, can't seem to find it or I haven't searched that much.
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Post by paydem on Nov 20, 2018 16:56:49 GMT -5
Ermkk,if I remember right your a 2t guy?? What size belt are you using?? Geoff Yes I am. The belt is stock size, 745x16.5mm. As I mentioned earlier the variator bushing is too short, I'll probably end up adding some spacers on it. I need new clutch springs, too. Anyways the question is does an overheated clutch bell make a big difference?
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Post by paydem on Nov 19, 2018 11:30:44 GMT -5
Noticed that my clutch bell has got blue-purple type of color around the center. I probably know how that happened - my clutch springs are too tight for my main spring, and the belt sits low on the TQ because I shortened my variator bushing. What's happening, I think, it needs to get a lot of RPM to get going and the acceleration is decent at best (the clutch slips when accelerating). My question is what difference does it make to CVT? Should I change it?
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Post by paydem on Oct 3, 2018 5:45:07 GMT -5
Words to live by
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Post by paydem on Oct 2, 2018 10:22:11 GMT -5
God dammit. Around my area there's tons of deers, and I nearly hit one during daytime doing 50mph. And most of the time I ride during nighttime, near forests and stuff. I almost never go slower than 40mph. I never actually gave it a thought of how bad it could end. Any guess on how fast you were going?
Get well soon.
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Post by paydem on Oct 1, 2018 9:39:37 GMT -5
Whatever, air screw tuning and dropping the needle clip one position higher fixed all my issues. Now it idles at all times. I guess I was too lazy to put more time on the engine and instead posted here.
I'll be more patient next time.
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Post by paydem on Sept 29, 2018 11:28:55 GMT -5
Today I fouled a plug first time in my life. I rode about 5-6 miles with 1/8-1/4 throttle. Then I attacked a steep hill at about 70km/h, then the speed dropped to about 60km/h at about 1/2 throttle. After the hill I rode maybe 100m and then the power dropped significantly, also heard a sound which sounded like a lot of rocks in the cylinder. After that I stopped. Kicked it over a few times, compression was OK. It started for a brief moment and died instantly. After that I took out the plug, cleaned it, and then it started first kick.. The engine doesn't run rich at any throttle position. I wasn't idling it for a long time or anything. I run 50:1 premix on a 70cc cylinder. If anyone has an opinion on why it fouled at such conditions, I would like to hear it. One thing though: I gapped the plug very low, maybe it could be the reason? Thank god I carry a spark plug tool with myself
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Post by paydem on Sept 24, 2018 14:28:47 GMT -5
Check the gaskets on all your intake stuff and make sure your throttle cable is sealed at the entry point to the carburetor. I agree with the "too lean" concept. There's no leaks on the intake, carburetor cap is sealed but the throttle cable has a loose fit on the cap. I don't think it's a big deal, probably I just need to tune it better. Will try to do it once the skies clear up, thanks for the help.
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Post by paydem on Sept 24, 2018 11:33:55 GMT -5
Check the float height. Maybe it's off and affecting idle. Turning the idle speed screw in a little doesn't let it idle? Alright I think I kind of lied here a little bit because I created this post after tuning it yesterday and didn't even test how it behaves when cold. So today it started and idled when cold, but after riding for 5 minutes it idles high and the clutch almost starts engaging. Also after letting it cool down for 5 minutes the idle comes down, and I need to give it some gas to get it started. After all it's far from perfect, I can't adjust float height since the float is non-adjustable. I can set it to idle at all times, but when hot, the idle is too high. What's strange to me is that when cold, the idle is lower than when it is hot. The choke works fine but it starts picking up RPM's when it warms up. It should be other way around, right?
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Post by paydem on Sept 23, 2018 12:29:27 GMT -5
Engine: Minarelli Horizontal AC, long case 70cc BBK (un-marked) Tecnigas Silent Pro exhaust Motoforce 17.5mm PHVA carb, jetting: 85 main, 38 pilot, jet needle 3/5, air screw 2.5 turns out, automatic choke Stock airbox with snorkel
When the engine is cold, it won't idle. The choke works, it just puffs out more smoke, but won't idle. When the engine is hot and the choke shuts off, it sometimes idles at ~2k RPM for about 5 seconds and dies. When tuning the carb, it idles fine, doesn't puff out lots of smoke, doesn't bog, the rpm's don't hang up. I can kick it one time without giving it any gas and it starts fine. I can let the engine cool off for about 5-10 minutes after tuning, and it won't idle again. And then again, after a 10-15 minute long ride I stop, the engine can idle for up to about 10 seconds before dying. The highest RPM's seems to be around 2-3 turns out on the air screw. I already tried dropping the jet needle up or down.
The engine doesn't have any leaks, the carb and airfilter is clean, the compression is fine, I run 95 octane with 50:1 premix. Any ideas?
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Post by paydem on Sept 19, 2018 6:34:51 GMT -5
So this weeks little problem,my front brake lever was not returning to fully off so the brake light was staying on unless I pushed it back manually,after a little head scratching it turns out that my brake cylinder valve was sticking.A strip down revealed some gunk in there and after a clean all seems to be fine,I did have a problem with a stuck brake piston which I could not move untill I connected the system up and clamped the free one closed, the pressure from the caliper popped it out I cleaned years of grime off it, back in working fine. geoff in took this picture a while ago but this is the original restrictor ring as fitted by Yamaha . Would love to know if you used old seals after stripping down the brake caliper, my handle is squishy too, no matter how much I bleed the brakes it's the same.
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Post by paydem on Sept 17, 2018 12:45:40 GMT -5
We finally got a break in the rain, its been close to 2 weeks, so I took the opportunity to get a ride in. Ran over a squirrel, that was nutty! It was ok. It was a well needed ride. I was gonna post the question if anyone has ever hit a squirrel with their scooter. There were a couple of close calls. They dart around back and forth so fast you don't know what the hell direction they're gonna go. So I just keep barreling forward with open throttle and hope they get the hell outta the way. One of these days there might be a splat, but I'm not sure how hard they'll hit the bike or if I need to worry about getting into an accident at 40+ mph. So the one you hit got up and walked away ryan _ott?? You really should be thankful that it's only squirrels and not something bigger.. Yesterday, while going 50mph (the speedo showed ~82km/h) on my Jog, a roe-deer jumped right in front of me. If I had not used the brakes and turned, I wouldn't be typing this right now.
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