Any tips for widening the ebay exhaust mounting holes?

Sullybiker · 06-30-2017, 02:45 PM

My ebay exhaust is on its way - I wondered if anyone had any tricks for widening the mounting holes in the stainless part that mounts to the cylinder. I know they have to be about a half inch.

I can get some tungsten carbide bits but this looks tricky on such a large existing hole. Those that simply cut it open at one end, what did you use?

Rangerscott · 06-30-2017, 03:03 PM

https://m.harborfreight.com/1-4-quar...ill-44460.html

**JerryHawk250** · 06-30-2017, 03:07 PM

A step bit like Rangerscott suggested or a thin cutoff blade on a grinder work great on stainless steel for cutting the ends open.

Megadan · 06-30-2017, 03:12 PM

It's not that tricky to drill the existing holes. I widened mine with a cheap set of titanium coated bits from Harbor Freight. The real trick is to spin that bit slowly, lubricate the bit with cutting oil (or any kind of light oil), and step up the sizes. The number one cause of burned up bits is heat, and heat is caused by high speed, high pressure, and friction. So spin it slow, let the bit do the work, and remember that you can never have too much lube

Sullybiker · 06-30-2017, 03:47 PM

Thanks all - very useful.

2LZ · 06-30-2017, 04:27 PM

Nip the ends out. Takes five minutes with a Dremel, tops. Cuts fast with little effort. I chose this method as it will allow it to stay centered as it expands and contracts in the exhaust port. Done two this way, zero issues.

Ariel Red Hunter · 06-30-2017, 04:39 PM

Quote:

Originally Posted by 2LZ

Nip the ends out. Takes five minutes with a Dremel, tops. Cuts fast with little effort. I chose this method as it will allow it to stay centered as it expands and contracts in the exhaust port. Done two this way, zero issues.

That is the way I recommend doing it...ARH

Sullybiker · 06-30-2017, 06:15 PM

Quote:

Originally Posted by 2LZ

Nip the ends out. Takes five minutes with a Dremel, tops. Cuts fast with little effort. I chose this method as it will allow it to stay centered as it expands and contracts in the exhaust port. Done two this way, zero issues.

I didn't think of the dremel! What bit did you use? I'll need to get one as I don't have any cutting wheels or anything like that, just various grinding stones and sanders.

2LZ · 07-05-2017, 10:15 AM

Quote:

Originally Posted by Sullybiker

I didn't think of the dremel! What bit did you use? I'll need to get one as I don't have any cutting wheels or anything like that, just various grinding stones and sanders.

I used the little cutting wheels. Four little cuts. They're super cheap at any Lowes, etc....

ricardoguitars · 07-05-2017, 10:29 AM

I did it with a bench grinder, using the edge of the stone.

timcosby · 07-05-2017, 01:33 PM

I did it the 2LZ way with cutoff wheel. Took all of five minutes

06-30-2017, 02:45 PM	#1
Sullybiker Join Date: Dec 2016 Location: Western PA Posts: 363	Any tips for widening the ebay exhaust mounting holes? My ebay exhaust is on its way - I wondered if anyone had any tricks for widening the mounting holes in the stainless part that mounts to the cylinder. I know they have to be about a half inch. I can get some tungsten carbide bits but this looks tricky on such a large existing hole. Those that simply cut it open at one end, what did you use?
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06-30-2017, 03:07 PM	#3
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,554	A step bit like Rangerscott suggested or a thin cutoff blade on a grinder work great on stainless steel for cutting the ends open. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
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06-30-2017, 03:12 PM	#4
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 7,986	It's not that tricky to drill the existing holes. I widened mine with a cheap set of titanium coated bits from Harbor Freight. The real trick is to spin that bit slowly, lubricate the bit with cutting oil (or any kind of light oil), and step up the sizes. The number one cause of burned up bits is heat, and heat is caused by high speed, high pressure, and friction. So spin it slow, let the bit do the work, and remember that you can never have too much lube __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
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06-30-2017, 04:27 PM	#6
2LZ Join Date: Mar 2010 Location: Volcano, Ca Posts: 7,081	Nip the ends out. Takes five minutes with a Dremel, tops. Cuts fast with little effort. I chose this method as it will allow it to stay centered as it expands and contracts in the exhaust port. Done two this way, zero issues. __________________ "Light a fire for a man, and you heat him for a day. Light a man on fire, and you heat him for the rest of his life." 2007 Suzuki DRZ400S (SM convert) 2009 Q Link XP 200 1967 BSA B25 250cc Starfire 2022 Royal Enfield Interceptor 650 2023 Royal Enfield Scram 411 1948 Royal Enfield Model G 350 Last edited by 2LZ; 05-26-2020 at 12:25 PM.
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07-05-2017, 01:33 PM	#11
timcosby Join Date: Nov 2016 Location: robertsdale alabama usa Posts: 1,007	I did it the 2LZ way with cutoff wheel. Took all of five minutes __________________ 1991 harley heritage softail classic 2016 hawk kaw h1 400 tripple 13' long chopper in progress 2009 johnny pag bar hog 2004 hd electra glide ultra classic shriner edition 1997 harley davidson 1200 sportster 1972 harley davidson amf sx250
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06-30-2017, 03:03 PM	#2
Rangerscott Join Date: Sep 2016 Location: Texas Posts: 165	https://m.harborfreight.com/1-4-quar...ill-44460.html
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06-30-2017, 03:47 PM	#5
Sullybiker Join Date: Dec 2016 Location: Western PA Posts: 363	Thanks all - very useful.
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07-05-2017, 10:29 AM	#10
ricardoguitars Join Date: Jun 2016 Location: Costa Rica Posts: 82	I did it with a bench grinder, using the edge of the stone.
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