KymcoForum.com
Scooters - 125 to 300 => Agility 125 => Topic started by: aschrauth on September 18, 2021, 10:16:37 PM
-
Good day everyone,
About a week ago I was doing my pre ride inspection and I noticed that one of the exhaust manifold studs and nut was missing (must have worked its way loose and fallen off) Anyway I cannot find the size of the nut or the stud that fits in the head. Does anybody know where I can purchase one from? I have already bought two off of amazon and both have not fit they appear too small. I would like to have the original stud and bolt setup.
https://www.amazon.com/gp/product/B07FRYC8CW/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B095CJTC25/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
-
Take the nut off the other side and go to Lowes, Home Depot, auto supply for studs and some kinda nut.
Think it's M6-1.0
-
Take the nut off the other side and go to Lowes, Home Depot, auto supply for studs and some kinda nut.
Think it's M6-1.0
Easier said than done. All my machines have long bronze nuts, I'm guessing to make them easier to remove after several years in service? Steel nuts will bind to the stud (because of the high temp) and break the stud on removal. Kymco parts catalog shows the nut as #90110-KFA6-900 SCREW PAN (M06X18)(SILVER). Kawasaki shows a similar exhaust nut as #92210 NUT,8MM 92210-Y006 The photo attached is from a WalMart listing!
-
@ashrauth,
this studs are M8x32
and those nuts are long M8 nuts but have instead of a 13mm head a 12mm hex head.
Means you can use ANY M8 bolt to fix your muffler again. Like CROSSBOLT suggests, see your HomeDepot of your confidence or any other hardware store.
This hardware need not to be posh quality. Hardens out anyway by time.
-
https://www.ebay.com/itm/322883068636?chn=ps&norover=1&mkevt=1&mkrid=711-160867-114178-3&mkcid=2&itemid=322883068636&targetid=4580428012964138&device=c&mktype=&googleloc=&poi=&campaignid=418451109&mkgroupid=1229254237204564&rlsatarget=pla-4580428012964138&abcId=9300595&merchantid=51291&msclkid=4db379b67f3f1126dc2218f13e3dc024
Might try contacting this seller.
Stig
-
https://www.ebay.com/itm/322883068636?chn=ps&norover=1&mkevt=1&mkrid=711-160867-114178-3&mkcid=2&itemid=322883068636&targetid=4580428012964138&device=c&mktype=&googleloc=&poi=&campaignid=418451109&mkgroupid=1229254237204564&rlsatarget=pla-4580428012964138&abcId=9300595&merchantid=51291&msclkid=4db379b67f3f1126dc2218f13e3dc024
Might try contacting this seller.
Stig
Stig
are these 8mm by 32? I couldnt find any dimentions on the ebay listing. I have asked the seller about it, This is what I wanted but Im not sure it is the right size.
-
I ended up purchacing these. They are the correct dimentions but like many others stated Im afraid that over time the bolts will seize themselves onto the thread due to the heat of the exhaust.
https://www.amazon.com/gp/product/B0089T063K/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
-
@ashrauth,
this studs are M8x32
and those nuts are long M8 nuts but have instead of a 13mm head a 12mm hex head.
Means you can use ANY M8 bolt to fix your muffler again. Like CROSSBOLT suggests, see your HomeDepot of your confidence or any other hardware store.
This hardware need not to be posh quality. Hardens out anyway by time.
I ended up purchasing something similar to this. Only thing Im afraid of is the bolt welding itself to the stud due to the heat from the exaust header. Stig mentioned an ebay seller that might have what I need but Im still waiting on a response to the correct dimensions.
https://www.amazon.com/gp/product/B0089T063K/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
-
anti seize is your friend when it comes to exhaust header bolts!
-
anti seize is your friend when it comes to exhaust header bolts!
I have some antiseze. Ill slap some on there when I install them.
-
Copper paste or ceramic smear are my favourites in such cases. Never had under normal circumstances seized bolts. Only if somebody messed with the thread and mounted tilted.
-
Copper paste or ceramic smear are my favourites in such cases. Never had under normal circumstances seized bolts. Only if somebody messed with the thread and mounted tilted.
That's true, and good advice. The only caution I'd add would be that your scooter exhaust is right down there in the mud and slush, so I prefer using the long acorn nuts whenever possible to try and keep the stud somewhat sanitary. Also you might find that (with a regular nut on a long stud) you might need to buy a deep socket. The long acorn nuts can be serviced with a normal socket.
-
@JJJ, you right about this nut lengths. Didn't think about that, for I have a whole workshop to my avail.
-
So I encontered a problem and may know why the nut and stud flew off in the first place. I went to install one of the new studs that was lost and noticed that it wouldnt Fully thred in the hole of the head. I have the correct 8mm stud. My only guess is that it worked its way out somehow and managed to strip the threads on the head. Bought an 8mm rethreading kit off of amazon and am going to attempt rethredding the stripped hole this weeke nd.
-
That's true, and good advice. The only caution I'd add would be that your scooter exhaust is right down there in the mud and slush, so I prefer using the long acorn nuts whenever possible to try and keep the stud somewhat sanitary. Also you might find that (with a regular nut on a long stud) you might need to buy a deep socket. The long acorn nuts can be serviced with a normal socket.
I wanted to use long acorn nuts but I cannot find any retailer that sells them in 8mm size, checked Amazon and ebay and looked at my local hardware store and didnt have any luck.
-
@ashrauth,
usually a stud, when it gets loose, does not destroy the thread in which it's located at.
The mufflers movement does.
However there is a reason why it got lost.
Mostly by overtightening. Then there might be some gunk or even a part of your old stud in there.
So, pry carefully with a small pointed tool to terminate how deep the thread really is. Compare depht with new stud. The shorter end goes into your cylinderhead.
Try now with a normal (softmetal) 8 mm bolt tenderly to log out what's going on there.
Keep in mind, a cylinder head is expensive.
Once you are sure the bore is deep enough to house your new stud, use your tap and tie set to
re-cut your thread.
Your thread cutter will be pointed, so it will NOT cut your new thread until the end.
You have to be very careful not to shear out your newly cutted thread.
-
@ashrauth,
usually a stud, when it gets loose, does not destroy the thread in which it's located at.
The mufflers movement does.
However there is a reason why it got lost.
Mostly by overtightening. Then there might be some gunk or even a part of your old stud in there.
So, pry carefully with a small pointed tool to terminate how deep the thread really is. Compare depht with new stud. The shorter end goes into your cylinderhead.
Try now with a normal (softmetal) 8 mm bolt tenderly to log out what's going on there.
Keep in mind, a cylinder head is expensive.
Once you are sure the bore is deep enough to house your new stud, use your tap and tie set to
re-cut your thread.
Your thread cutter will be pointed, so it will NOT cut your new thread until the end.
You have to be very careful not to shear out your newly cutted thread.
I'm not sure how it happened. I have installed numeroous helicoil inserts and normally have good results. Trick is to use lubricant and have patience.
-
I'm not sure how it happened. I have installed numeroous helicoil inserts and normally have good results. Trick is to use lubricant and have patience.
My big problem with Helicoil and similar is the drill bit hogging into the hole too fast. So adopted modifying the special tap drill by grinding the cutting edge to a smaller rake. More like a scraper and less like a chisel. Works on drilling plexiglas, too!
-
Ah okay, didn't know you have already experience with helicoil or similar. 👍
-
I wanted to use long acorn nuts but I cannot find any retailer that sells them in 8mm size
You won't find these at Home Depot! Learn to find your scooter parts online, they're there and not difficult to find. This is from Amazon, nuts, bolts, gaskets, etc, all for $9.95:
https://www.amazon.com/1PZ-EBG-001-Scooters-Sandrail-Coolster/dp/B0777JNVKC
-
@JJJ, very good source.
But this studs are 6mm pieces (pls see screenshot from this offer) and can't be used on our motors.
-
You won't find these at Home Depot! Learn to find your scooter parts online, they're there and not difficult to find. This is from Amazon, nuts, bolts, gaskets, etc, all for $9.95:
https://www.amazon.com/1PZ-EBG-001-Scooters-Sandrail-Coolster/dp/B0777JNVKC
Bought one of those and had to take it back to Amazon. Not the right size, the bolts on the head are 8mm.
-
I wanted to use long acorn nuts but I cannot find any retailer that sells them in 8mm size
You didn't say what machine you're working on, so we readers are mostly guessing at what might work. Almost all scooters use the 6mm bolts, so if your machine is 8mm, you could contact the maker and get the factory bolts?
-
Pls see..
https://www.kymcoforum.com/index.php?topic=31668.msg221737#msg221737
-
Pls see . . .
LOL! Now that we've circled around the the beginning again, can we assume that we've found useful solutions to this problem?
-
I have already fixed the issue. The studs are 8mm. Bought an 8mms helicoil kit and tapped threads and reinstalled new hardware. As far as I'm concerned I shouldn't have a problem with just using bolts to hold the exaust.
-
@aschrauth good to read you solved.
And yes, using 8mm bolts of any quality would be a solution, but a temporary one only.
Using studs on nearly any motor seen has several reasons.
- thermal stress is less on studs
- all exhaust studs or bolts harden out by time
- it's way cheaper /easier to remove a broken stud than bolt which shears nearly always even with surface
- studs have a non thread part which allows the muffler flange to "vibrate" a little to avoid greater damage on an expensive silencer.
-
@aschrauth good to read you solved.
And yes, using 8mm bolts of any quality would be a solution, but a temporary one only.
Using studs on nearly any motor seen has several reasons.
- thermal stress is less on studs
- all exhaust studs or bolts harden out by time
- it's way cheaper /easier to remove a broken stud than bolt which shears nearly always even with surface
- studs have a non thread part which allows the muffler flange to "vibrate" a little to avoid greater damage on an expensive silencer.
I plan on using the 8mm Nuts temporarily until I can order some longer ones. Went to my local Lowes and all they did not have any metric size coupling nuts. I might have to get some from amazon.
-
Here are some pictures of the repair if you all are interested. Upper left hole is the one that is repaired with the helicoil.
file:///C:/Users/alexs/Desktop/IMG_20211003_141913.jpg
-
Here are some pictures of the repair if you all are interested. Upper left hole is the one that is repaired with the helicoil.
file:///C:/Users/alexs/Desktop/IMG_20211003_141913.jpg
Link is inop...
-
If you plan to order anyway, take copper or brass nuts.
And BTW, don't have access to your c-drive to see pics 😊
-
If you plan to order anyway, take copper or brass nuts.
And BTW, don't have access to your c-drive to see pics 😊
Yep -my Piaggio uses yellow nuts on the exhaust studs (copper/Brass?)
I do not see pics either.
Stig
-
Went to my local Lowes and all they did not have any metric size coupling nuts. I might have to get some from amazon.
From experience, I don't recommend lumber-yard bolts. They're lower quality steel, inclined to snap off some time in the future. Try to find the hi-strength steel hardware from the manufacturer, or online from Amazon, with the long bronze nuts. Remember this connection runs red-hot while soaked in rain and dirt, and the bronze nut covers the thread completely so it can be removed easily after years of abuse!