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Post by dexameth on Apr 23, 2020 20:42:15 GMT -5
That was after about 30 kicks... I forgot to prime the carb so I was relying on engine vacuum to activate the petcock, but it eventually fired right up.
Went and filled up 1.07 gallons and added just over 3oz of oil. Spilled some, was inevitable, but I know I got more than three ounces so I'm like 42:1 mix.
Lap around the block and she is SO MUCH SNAPPIER. No more electric start, and the tiny flywheel make the engine rev super super quick. Got up to 57mph to hehe. I gotta check the plug and see where it's at, but I think we are fine. Lil rich before so now with premixing leaning it out it might be spot on. Plus there's the power jet.
Calling for rain tomorrow so I'm torn which scoot to ride... luckily I have invested in a rain suit and boot covers so I'll stay mostly dry.
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Post by dexameth on Apr 24, 2020 8:08:08 GMT -5
Yup, totally rain. The new Bilt rain suit did great tho! As well as Maddy, she ran good and strong all the way...
except
Faulty kill switch / rain short circuited it.
Outta nowhere, while cruising at 48, she just shut down. It was literally like somewhat flipped the kill switch. I pull over, a homeless dude hiding under this carport says "I bet you're outta gas". I just filled up last night.
Just because, I flip the switch, then back to run and she fired right up. Make it a few blocks, turn and she does it again! Kick, kick, kick, over and over and nothing. Flip switch back and forth, first kick she fires up.
Dang! I thought I had her pretty much good to ride with no worries. Easy fix though, really. I just can't wait to get her out on a nice day with no rain and see what she has!!! So much power at hand now... and I swear my squish can be improved (not to mention case porting and trenching).
Happy Friday!
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Post by dexameth on Apr 27, 2020 9:50:12 GMT -5
Well dang... it happened. Don't know how, I had checked the plug about 30 minutes prior to the incident. Cruising at 32mph, mid throttle, and I heard what sounded like a .22 rifle firing off underneath me. Total loss of power. Right in front of a sheriff.   And believe it or not... the cylinder actually didn't get too messed up! But, I did pull a rookie mistake in the midst of excitement: I forgot the damn wrist pin circlips. No joke. Take a look at the cylinder and notice the wear groove from the wrist pin. If that little "bridge" wasn't there it would have snagged the port and left me with a much worse day.   DOH! Live and learn, I guess. But, we are completely out of stock on cast iron cylinder/piston kits with 10mm pins. I really wanted to take home a "regular" kit today but we only have one in 12mm wrist pin size or Athena or Hoca ceramic again. We don't even have a 47mm piston with 10mm pin in stock either. I could totally buy another 47.6mm piston and pop that back in there, and I think I'm going to. If you think about how far down the ring goes at BDC, it really isn't going to expose the deeper grooves on the bottom but barely touch the little groove above the small port. Meaning, I should still get good piston-to-cylinder seal (I hope). My only other option is to leave all the go fast stuff on there, and install the stock cylinder kit again. Remember, this would be stock cylinder with stroker crank, light flywheel, taller gears and full CVT upgrade. Got me wondering if it'd push those taller gears; if not it's not too hard of a swap. Also: On my ride home from the weird "kill switch" failure I had gone over train tracks that were rough and it led me to sputter the last 2 miles. Raining, I just hoped I'd get home... and I did. Next morning I go out to inspect and the damn ignition coil wire (space connector) was completely loose and wiggling around. Pinched it tight and she fired right up and sounded MUCH healthier. Then, I found an air leak at the vacuum line to the petcock. I strongly believe that was my air leak this entire time. I used two zip ties to secure it down and boy oh boy does it seal now. Everything fired up - rode 15 minutes to a friends house, on the way back is when she popped. So... 40mm with stroker kit? Or... 47.6mm new piston and just send it? |
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Post by 190mech on Apr 27, 2020 11:58:12 GMT -5
Part throttle has killed many a good 2stroke!There will be metal bits packed in the bottom end,,you may get lucky with a good flush out,but maybe not...
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Post by dexameth on Apr 27, 2020 12:05:51 GMT -5
you may get lucky with a good flush out,but maybe not... I got lucky with Stella's engine by taking cylinder off, then intake off, then pouring gasoline down were the reed block is and hand cranking it while allowing the gas to spill out the cylinder bore. Sure, it's messy and wasteful but it did the trick. I was going to do that tonight on this engine, after purchasing a new air compressor, and hope for the best. |
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Post by 90GTVert on Apr 27, 2020 12:26:34 GMT -5
I'd go for the 47.6mm and see what happened. Once you ride a good setup like this, you can't just go back to stock cylinders. I'd at least pull the engine out, drain the gear oil, remove the rear wheel to make it easier to work with, do plenty of flushing and turn it cylinder end down. Once flushed, put some drops of 2T oil in all bearings and turn it over and check for play and noise. Don't forget to shake the pipe around and see if it rattles. Blow some air through there at least. One of mine ate a wrist pin bearing. I actually took care to make sure the pipe wasn't rattling, blew it out and so on. Got it all back together and it put a hurtin' on a new setup. Something either came out of the pipe or the engine that was cleaned and flushed. That's why we mention this stuff. It's a little risky anytime it's not a full disassembly in the first place and it really sucks when new parts are ruined quickly. Also, since this happened just after a new ignition; whenever it's running with any cylinder kit again you need to pay attention for knock. Not a bad idea to see if you can find out where the timing is. Good news there is that the cheapest eBay/AliExpress timing lights seem to work better with some racing ignitions. ( Example) Don't forget to make sure it's rich at part throttle. Maybe check the plug style. Not sure what your cylinder likes, but I know the race stuff calls for a 10 series NGK (cold) compared to the 8 series that I've always ran in sport-type iron bores of all sizes. Also, part throttle is scary with these. I ride around revving and bucking like a jerk anymore because I really don't like hanging out at one low throttle position for any length of time. It's bad enough with iron bores, but stuff can go south so fast with these things. That's how you know two-strokes are the most badass engines. They may punish you if you don't run them WOT. |
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Post by dexameth on Apr 27, 2020 14:03:09 GMT -5
I'd go for the 47.6mm and see ... Thanks man, I know you know a lot about ignition on these and I was gonna ask about this flywheel specifically since you installed it... WHERE ARE THE TIMING MARKS? Haha I might have to scribe in my own TCD marks then my own mark about what, 15° back as a starting position? I installed the plate to where I thought was factory timing, and it started and ran fine and I didn't hear anything out of the ordinary. I do need to get a timing light... I did notice a good amount of debris in my pipe when I pulled it off. Last night right at sunset I pulled the engine inside. I have already removed exhaust, cylinder, piston and intake/reed block. I'll pull the wheel if I need to but I'm sure I'll be able to flush it all just fine. The way you explained is my exact intentions. Plus, the wrist pin groove does seem low enough to get away with running the new piston. I'll only go back to stock if absolutely necessary. |
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Post by geoffh on Apr 27, 2020 14:10:18 GMT -5
Dexameth,did you forget to fit the wrist pin clips and have them on the bench ,or like me fitted them wrong and they ended up embedded in the piston,there is a right way to fit them.
Geoff
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Post by dexameth on Apr 27, 2020 14:23:32 GMT -5
Dexameth,did you forget to fit the wrist pin clips and have them on the bench ,or like me fitted them wrong and they ended up embedded in the piston,there is a right way to fit them. Geoff I didn't even install them... left them on the little work stand next to my bench. Found them the next day, with others, and though "I think those are supposed to be inside". I guess I was too anxious to get everything together. Luckily for that little bridge though - it saved me! |
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Post by geoffh on Apr 27, 2020 15:01:39 GMT -5
Yes tricky little so and so,s I lost one while I was rushing a build,I saw it on the concrete floor the other day but by the time I had tilted my bifocals to reach it the gremlin,s had hidden it.  Geoff |
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Post by Zino on Apr 27, 2020 16:05:21 GMT -5
10,000 rpms without wristpins amazing.
With all the work you put into that you have to at least get a 47.6 cylinder .
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Post by 90GTVert on Apr 27, 2020 16:10:53 GMT -5
WHERE ARE THE TIMING MARKS? Haha I might have to scribe in my own TCD marks then my own mark about what, 15° back as a starting position? I installed the plate to where I thought was factory timing, and it started and ran fine and I didn't hear anything out of the ordinary. I do need to get a timing light... At least on mine, they just give you some hash marks by the bolts. Just helps you put it in the same spot if you find what you like, but doesn't tell you timing. You would need to setup a timing pointer and make a mark on the flywheel that corresponds with TDC. Alternatively, some people mount a small degree wheel to the flywheel. Make sure it's not something that's gonna fly apart or be a big hazard. Can be done the opposite way with a mark on the flywheel that corresponds with TDC when an external degree wheel (cutout the inside so you've just got a ring with timing marks) is on 0. When you don't have an adjustable light (again, mine didn't work with my MVT or the HOCA kit), you need to have some marks to figure out where you are and the degree wheel is probably the easiest. You could take the time to mark your flywheel and then you'd just need to setup a pointer each time directly on it's 0 TDC. Here's an example of the external ring. I made mine from steel, but you can do it with a paper one or something. Pitobread shows that in his ignition setup vid. youtu.be/JuehGGccJhM?t=170 |
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Post by dexameth on May 7, 2020 7:59:24 GMT -5
Dang, late update haha!
So, she cleaned up very nicely inside the crankcase. Gasoline is cheaper than Mineral Spirits so I drained some of the old stuff outta poor Sonja just sitting there. I threaded on the flywheel nut to the crank, then used my cordless drill to spin the crank while I poured gas in and it started flushing itself. Compressed air to blow it all out and dry it up.
Reassembled again with three base gaskets and no head gasket - my digital caliper died and it looks like just a hair under 1mm of squish, maybe .9mm. I believe the stator plate is still clocked to what I think is stock timing. Fresh B9HS plug and a new piston which I did have to file the ring open a tad bit. Installed a 112 main, up from 107 and moved needle clip to middle. Fired 2nd kick! I used a good amount of oil during reassembly and that turned the neighborhood blue for a bit haha
She seems to have more power than before! Like... front wheel just lift if you crack WOT from a stop... when she's cold. After she warms up you gotta give it a lil pull, help the bars come up, but damn does she ever! Like, this is a crazy snappy and quick build for sure. Way way more than I thought it would be. It would absolutely accept even taller gears.
I have managed to maintain 59mph, full tuck. She rockets off the line, and pisses off cagers BAD. Everyone on the roads now thinks I'm racing when I'm just enjoying the ride haha!
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Post by dexameth on May 8, 2020 14:59:02 GMT -5
So I added all the spacers that make up the room from the starter clutch and added them to the drive boss. 3mm + stock spacer + boss. The 788x17 belt sits almost perfect at the top of the rear pulleys and sits right down against the boss now. Take off is MUCH MUCH better, super snappy and I still do near 60... what's weird is there's almost 3/4" left on the pulleys! So, I changed belts to the Malossi overrange belt. Immediately was too long with all the spacers. Removed the spacers to "stock variator" setting and it sits kinda better...   But, the clutch engages SOONER now. Like, too soon. Nice mid range with this belt, crappy takeoff and top end I haven't pushed over 52mph yet. I think I'm going back to the 788 belt. Oh, I finally cut a hole in the CVT case to allow a little extra cooling.  Gonna enjoy this weekend ripping around town! |
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Post by Zino on May 8, 2020 15:10:41 GMT -5
Is that a Long Case Minarelli.
I found the same thing when I went to a larger pulley in the back My clutch was engaging sooner.
My AHA moment was that
My tach only keeps track of how fast the front pulley is turning.
When I change the Gear ratio between the 2 pulleys .
I am spinning the rear pulley at a different speed in the back compared to the front so the clutch engagement changes .
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