mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 11, 2019 10:00:34 GMT -5
So you can see i totally screwed the pooch on the cam, not only was it backwards but it didn't line up at all. No worries, immediately saw what was wrong, took everything out, got it back lined up correctly, everything was going smooth. took my time and in a star pattern, butting the head bolts on slightly snug, taking my time, then got my torque wrench out, set it up with 13 ft pounds and in a star pattern again- not in a rush, started to torque down my head bolts... then the upper right long head bolt sheered off. so back to square one. if you can notice the "core"" of that head bolt looks like taffy, cheap crappy Chinese metallurgy. i hopped right on and ordered some of these studs to replace the one i busted. i might as well do all 4.
so that's where i stand. dead in the water. at least it sheered off above the valve head and i was able to get it out without pulling the entire head and jug. im so annoyed im day drinking now.
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Post by scooterted on Nov 11, 2019 11:20:09 GMT -5
Oh geeze. You cant catch a break. At least youve found the problem, and extracting that stud didnt sound like it was a problem. Dont worry about the cam being in backwards, not possible. Cam position determines what stroke the crank is on. Just make sure the crank is at top dead center and the two small holes on the cam gear are level with the top of the head and youll be fine.
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 11, 2019 11:40:58 GMT -5
Oh geeze. You cant catch a break. At least youve found the problem, and extracting that stud didnt sound like it was a problem. Dont worry about the cam being in backwards, not possible. Cam position determines what stroke the crank is on. Just make sure the crank is at top dead center and the two small holes on the cam gear are level with the top of the head and youll be fine. no it came right out with some lock-pliers. at least parts for scooters is local, i got my valve head in one day via USPS priority mail. i can likely get it back in middle of the week. If i had another car i would just run up to partsforscooters, its like a hour away, but the wife has the car today so ill just have to wait for the mailman.
EDIT: Shotout to our Boy dexameth for reminding me i need two long and two short for the cylinder bolts! Called Parts for scooters and the fixed it right away.
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 13, 2019 19:22:08 GMT -5
Hey guys. So I got that new bolt in, but now a different problem. I ditched that direct air intake filter contraption and went back to stock air. Started with a 94 main and it's a 33 pilot, good idle on stand at 2000 rpm. Problem is when under load and WOT, tops out at 20 mph and has a strange sound, buzzy sounding. Slight bog occasionally with WOT. I keep going back and adjusting the valve lashing, to me has been pretty difficult.i adjusted it twice tonight. I'm TDC via flywheel and my cam is lined up correctly. What could be the no power and weird sound? I'm second clip from the top on the needle so that would make it slightly lean, can this be due to a lean condition?
I've gotten pretty good and opening the valve cover, going tdc and adjusting valves. I've been trying to get them set to .004 what am I missing? I can do a video this weekend to show the sound and from gauge.
So frustrated, been down a month.
Any ideas?
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Post by scooterted on Nov 13, 2019 19:40:44 GMT -5
Why do you keep swapping intake setups? You just have to keep starting over.
Is your valve lash changing? Or are you just rechecking?
Air fuel ratio being off can make a change in engine sound.
Try moving the needle and swapping jets.
Edit: "Bogging" is usually how rich is described. I would go up a jet size and see if it gets worse.
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 13, 2019 19:58:41 GMT -5
Why do you keep swapping intake setups? You just have to keep starting over. Is your valve lash changing? Or are you just rechecking? Air fuel ratio being off can make a change in engine sound. Try moving the needle and swapping jets. I changed back to stock because I couldn't seem to get the air fuel mix right, I dialed it in pretty fast once back to stock air. I don't know what's going on with the valve lash, I'm using needle noses on the lash pin and once I find the correct spot with just a little drag I tighten the nut down and tighten it up. Consistently throughout this whole ordeal I have never gotten it to perform correctly. i appreciate the help though seriously. I'm going to change the needle position to middle the ride test it and take it lower if no improvement.
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Post by scooterted on Nov 13, 2019 20:13:58 GMT -5
I see. Setting the lash can be a pain. I bought the tool pfs sells and it makes it a little bit easier.
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Post by scooterted on Nov 13, 2019 20:20:27 GMT -5
Aside from mixture, im out of ideas except for checking your compression, everthing is new though, so that shouldt be a problem. Maybe spark plug gap. Idk.
With all this work under the valve cover. Are you remembering to reinstall the ground?
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 13, 2019 21:41:02 GMT -5
Aside from mixture, im out of ideas except for checking your compression, everthing is new though, so that shouldt be a problem. Maybe spark plug gap. Idk. With all this work under the valve cover. Are you remembering to reinstall the ground? The ground on my scoot was never attached to the valve cover as far as I know. looks like it may be mounted by the starter. The plug I got was supposed to be pre-gapped but I'm thinking along the same lines as you are. I'll take a look and see if a gound inadvertently got disconnected but I haven't seen one tbh. And I'm picking up a gap gauge this weekend at autozone for sure. I'll slap myself if it's that. I might end up saving up for a good carb, all these aftermarket carbs seem janky.
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 15, 2019 14:55:56 GMT -5
So I'm going to take another run at this scoot this weekend. I replaced the one broken head stud but I'm going to replace the other 3, double check my tdc and get the head torqued back to 14 ft pounds (19 nm).
Going to replace the spark with a nice CR7HIX Iridium IX Spark plug.
My needle is 2 from the bottom so I'm going to recenter the clip and try that. I am running a 33 pilot and 94 main on stock airbox, had no issues with getting to run a clean steady idle.
Anyone have any idea what the low power, buzzing sound could be? Valve lash? Using my valve lash set I get it set with light drag at .004.
It will rev on stand to almost 8k, but on road under load has that buzzing and low power.
Last attempt I think at home. Might have to bite the bullet and take it to a shop, but that's going to be expensive and can't really afford it.
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Post by scooterted on Nov 15, 2019 22:20:15 GMT -5
I really dont know what the buzzing is. Maybe take the cvt apart and inspect?
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Nov 16, 2019 15:00:40 GMT -5
I really dont know what the buzzing is. Maybe take the cvt apart and inspect? The scoot is finally fixed! The valve lash was still off, opened the valve cover, pulled the plug and set tdc via fly wheel,cam was lined up perfect. Checked the valve lash. Way off again. I think either I didn't read the drag properly or I didn't tighten down the valve nuts properly. Got it set for .004 on the ext and intake, upt the cover back on and put in the New iridium plug. Fired right up. Shut it down and dismounted the carb, cleaned out the carb and all passages with carb cleaner, put in a 90 main jet. Rode it around a bit alternating between wot and 1/2. Bike tops out around 7800 and about 31-32 mph, but I haven't had on a long stretch yet to see how far the cvt will open up. Took it back and gave it a oil change. I noticed while doing the runs and coming back to check the needle position it seems to like the middle position. I'll leave it alone for now and see how it performs on my commute on Monday. I'm sure I could wring a bit more out of it by adjusting the jet size but that's not a pressing issue. I want to thank scooterted and dex from partsforscooters.com, both of you were very helpful and to everyone else who chimed in here in the thread. The buzzing was from that janky trunk that came with the scooter. I took it off. Scoot looks better. This was a aggravating but a wonderful learning experience and makes me more confident in the future to tackle other project on it. Thanks guys!
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Post by jloi on Nov 16, 2019 20:47:21 GMT -5
good for you.
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Post by crabjoe on Jun 19, 2020 21:47:17 GMT -5
Sorry to revive this old thread, but what am I missing?
You went from a 50cc to 72cc (47mm BBK). How is it that after you got everything running, you're only getting 31mph? Isn't that pretty my standard top speed on most all stock 49cc scoots? Did you at least gain a lot of acceleration with the BBK versus stock?
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mikeh
Scoot Member
Posts: 59
Location: Bradenton, FL
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Post by mikeh on Jun 26, 2020 13:44:37 GMT -5
Sorry to revive this old thread, but what am I missing? You went from a 50cc to 72cc (47mm BBK). How is it that after you got everything running, you're only getting 31mph? Isn't that pretty my standard top speed on most all stock 49cc scoots? Did you at least gain a lot of acceleration with the BBK versus stock? Sorry I haven't been around for a bit, busy at my waterplant. No the top end is around 42-43, cruises well at 40. Pulls over a large inclined bridge at 30-35. The scoot has ran fine but has been garaged for quite a wild, been driving my car to work mostly. Started it up and ran it around the neighborhood this past weekend. Still very zippy, gets up to 30-35 very fast. Considering eventually putting in a 50mm bbk and stroker crank. Am very curious where to get upgraded gear sets, with the 47mm I feel even it is being limited by gearing ratios.
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