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Post by 90GTVert on Apr 21, 2023 7:29:22 GMT -5
I replaced the rear tire. These Michelins on the Aerox wheels are such a pain. The Battlax on the TMAX is also bad and I did that the same day so that was fun. Seriously considering some sort of tire machine. I really like both scoot setups, but I have to fight tires onto them. The stuff tires are nearly impossible to keep in the drop center. They want to be up on the beads. I think if I had a manual setup with a duck head, life could be much easier and tire changes wouldn’t be accompanied with dread and loathing. The ready made stuff is either cheap and not suitable for scoot stuff and not great or expensive and not suitable for scoot stuff… and sometimes still not great. I looked at steel prices and I could easily spend a couple hundred to build something, plus likely a lot of time. Not today… but seriously considering something in the future. I took a test ride with the new carb bracket, smaller pilot jet and larger main jet. It runs REALLY poorly somewhere around 1/8 to 1/4 throttle. Previously it just seemed too rich, but now it’s bad enough to try to die or at least momentarily lose power when holding certain throttle positions. Basically anywhere I need for cruise is unusable, so it has to be a bit of a light switch. It runs as strong as ever otherwise, but will still get hot holding WOT. When I got back, I immediately noticed raw fuel on my rear wheel that was cleaned prior to the ride. Then saw raw fuel on the mudguard. The bracket does seem to be keeping the carb from contacting the mudguard BTW. I guess I had an already rich condition down low and the carb staying at a greater angle now has exacerbated it. Could be that float height was too high in the first place and I just made it worse. Boy do I enjoy playing with float height constantly on this thing. 🤦♂️
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Kaos
Scoot Enthusiast
Posts: 185
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Post by Kaos on Apr 21, 2023 9:57:16 GMT -5
I replaced the rear tire. These Michelins on the Aerox wheels are such a pain. The Battlax on the TMAX is also bad and I did that the same day so that was fun. Seriously considering some sort of tire machine. I really like both scoot setups, but I have to fight tires onto them. The stuff tires are nearly impossible to keep in the drop center. They want to be up on the beads. I think if I had a manual setup with a duck head, life could be much easier and tire changes wouldn’t be accompanied with dread and loathing. The ready made stuff is either cheap and not suitable for scoot stuff and not great or expensive and not suitable for scoot stuff… and sometimes still not great. I looked at steel prices and I could easily spend a couple hundred to build something, plus likely a lot of time. Not today… but seriously considering something in the future. I took a test ride with the new carb bracket, smaller pilot jet and larger main jet. It runs REALLY poorly somewhere around 1/8 to 1/4 throttle. Previously it just seemed too rich, but now it’s bad enough to try to die or at least momentarily lose power when holding certain throttle positions. Basically anywhere I need for cruise is unusable, so it has to be a bit of a light switch. It runs as strong as ever otherwise, but will still get hot holding WOT. When I got back, I immediately noticed raw fuel on my rear wheel that was cleaned prior to the ride. Then saw raw fuel on the mudguard. The bracket does seem to be keeping the carb from contacting the mudguard BTW. I guess I had an already rich condition down low and the carb staying at a greater angle now has exacerbated it. Could be that float height was too high in the first place and I just made it worse. Boy do I enjoy playing with float height constantly on this thing. 🤦♂️ I'm spoiled on the tire front. There's a dirtbike shop a mile from my house that'll swap my tires and balance them for $10. At that price its not worth it to keep a tire machine around... Also, I dig those wheels. I'm trying to figure out nicer wheels for mine but its hard to figure out a matching set when its a GY6 front, and a Vespa GTS rear.
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Post by 90GTVert on Apr 21, 2023 10:29:02 GMT -5
Also, I dig those wheels. I'm trying to figure out nicer wheels for mine but its hard to figure out a matching set when its a GY6 front, and a Vespa GTS rear. These are Aerox wheels, but they aren't going to fit a GTS. You can probably do some "close enough" matching... possibly requiring a hub setup. There seem to be a lot of custom wheels for the Vespa and there are a lot for the GY6... but for the front it doesn't really matter if it's a GY6. Lots of scoot stuff could be adapted. 10 and 12mm axles are common for fronts and you can just swap bearings most of the time and make it work or drill fork tubes to go larger.
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Kaos
Scoot Enthusiast
Posts: 185
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Post by Kaos on Apr 21, 2023 10:31:07 GMT -5
Also, I dig those wheels. I'm trying to figure out nicer wheels for mine but its hard to figure out a matching set when its a GY6 front, and a Vespa GTS rear. These are Aerox wheels, but they aren't going to fit a GTS. You can probably do some "close enough" matching... possibly requiring a hub setup. There seem to be a lot of custom wheels for the Vespa and there are a lot for the GY6... but for the front it doesn't really matter if it's a GY6. Lots of scoot stuff could be adapted. 10 and 12mm axles are common for fronts and you can just swap bearings most of the time and make it work or drill fork tubes to go larger. Thats kinda how I'm leaning. I'm thinking of finding a GTS front hub and see if I can get the wheels to work via bearing swaps. The GTS's wheel setup is weird, the hub isn't part of the wheel. Its a separate unit. Its also a 12 inch rim on a 10 inch fork, so we'll see if that matters. And the GTS forks are single sided... But I THINK I can make it work. Whatever I do, my front wheel is a boring as hell stamped steel wheel, and THATS no good
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Post by 90GTVert on Apr 21, 2023 12:29:14 GMT -5
I lowered the float height from about 20.8 to about 21.5mm. Took a quick ride around town and it doesn’t look like the carb is overflowing ATM.
It still has a bad spot though. My markings have got a little off, but it’s right around 1/8 throttle and not for much of the throttle. Still missing and acting up right there.
I’ve never really though float height should mess with that area specifically, but when fuel is leaking you focus there first and hope. Not sure what’s up. Nothing looks way off in EGT.
I couldn’t see anything in either passage that I threaded, but it does make me suspicious. Guess I could remove the bracket and let the carb ding up the mudguard long enough to see if it goes away. If it were some air passage suddenly blocked (again, I don’t think so) I’d think a small hole through the center of a bolt could fix that and still allow support.
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Post by 90GTVert on Apr 21, 2023 13:19:30 GMT -5
I just took the bracket off and no weird spot. I guess there must be an air passage that I was unaware of. Next project will be a bolt or bolts with through holes. Hoping the lathe may help, cause my drill press ain’t doing that.
It wants to rip at around 1/4 throttle now. I left a stop sign and it came up fast as I got around 1/4. If I hammer it, it slips, so the belt has prob been in there too long.
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Post by 90GTVert on Apr 21, 2023 13:55:44 GMT -5
M6 with a 2mm through hole.
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Post by oldgeek on Apr 21, 2023 16:25:01 GMT -5
I believe the carb mount is going to be too rigid as you thought.
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Post by rollingbender on Apr 21, 2023 16:55:53 GMT -5
Happy medium for the carb support might be to cut a short section out of the round part between the carb and the bend and “re-connect” with a piece of hose that has a nice slip fit over the rod. Keep the carb off the fender a bit but still let it move a little too.
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Post by 90GTVert on Apr 21, 2023 19:52:26 GMT -5
I put the "breather bolt" in the intake side hole and it acted up, but didn't seem as bad. I put it in the rear and it seemed just as bad as before. I'll try 2 breather bolts and see what happens. It's leaking fuel again though. The only ride that it didn't act up... no fuel leak... but that was also the only ride with no support... so there's still no certain answer there. I'll do the 2nd bolt when I get a chance and I guess then we'll know what the answer is... or then I'll question if the bolts breathe enough. lol
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Post by 90GTVert on Apr 22, 2023 8:00:49 GMT -5
I made a 2nd breather bolt and enlarged both to 2.35mm (3/32”) through holes. Installed both and the issue persists. OK. So either they need much closer to full flow of the original “ports” or this is all nonsense and I was correct initially that the passages do nothing. Simply some extra cast spots prob for some other configuration of this carb. I took the bracket off, but installed both breather bolts. It ran fine. There may be some very minor odd feeling at the specific throttle position, but nothing that wasn’t there before all of this and nothing that I’m terribly worried about. Next up, I’ll try cutting out a small piece of the rod and connecting the leftovers with a short piece of hose as rollingbender suggested. I wasted a good bit of time worrying about those ports, but at least this way I’m satisfied that we have a pretty good conclusion about any possible airflow/venting harm vs good old fashioned vibration transmission. Not a good idea to bolt the carb straight to the engine case essentially.
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Post by 90GTVert on Apr 22, 2023 12:53:53 GMT -5
Just when you thought my bracket couldn’t get any uglier, I cut 1/4-3/8” out and connected it with fuel hose. Just took a 31 mile ride and that seems to still let it function at low throttle. Found a new problem just before I got home. I went WOT and it tried to die. I was going around a corner so I wasn’t looking at gauges, nut 60+MPH and I know the EGT was 130_ when I looked down after. Tried WOT again after slowing down and it was cutting out just over 60. I guess now the carb is a little too angled. Prob more than before. I loosened one clamp and pushed the bracket in more to lessen the angle slightly. Maybe that’ll do it. This thing has always seemed to live on the narrow path between overflowing and running dry.
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Post by 90GTVert on Apr 22, 2023 14:42:52 GMT -5
The slight adjustment to the bracket didn't change anything. I moved float height back to roughly where it was before all of this. Don't see any leaks. It did start to die once, but it was also at 1379 EGT and 78MPH. Prob need to put a larger main jet in and still raise the float just a little if it will take it.
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Post by rollingbender on Apr 22, 2023 16:01:50 GMT -5
… and now you have an adjustable carb support/buffer. Win!
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Post by 90GTVert on Apr 23, 2023 19:00:47 GMT -5
Changed the float height a little and installed a 150 main jet this morning. Took a sorta long ride and wound up at a friend's house. The bowl still ran dry WOT with high EGT.
I came back and adjusted the float height more. Left the jet alone, assuming it may be the low fuel causing high EGT as well. I tried to run it WOT and it died... and stayed dead. Out of gas. Got a roadside delivery of premix and held it WOT a few times on the way home without issue. Didn't try to cut out and stayed under 1350 EGT. I'm not calling it good yet. I would like to see it do it again.
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