Doing Hawk things.

[Megadan]

I decided to revisit the exhaust I bought almost a year ago and try to make it work just to see if there is any loss from it having a catalyst compared to the normal "ebay" exhaust 99% of Hawk owners run.

It's not available at the moment, but this is a link to it if you decide that you too want something that doesn't fit and needs fabrication. https://www.amazon.com/exec/obidos/A...im/refuge08-20

Before I delve into things too much, you may notice my plain jane carb and filter setup. I already did an experiment with carburetors on the Motocult head and big bore setup with the 292 cam. One for curiosity sake, and the other just to prove a point to people that obsess over having the biggest carb they can manage to fit on the Hawk. Yep, that's a "Mikuni VM26 30mm" It took me 5 minutes to setup, and one main jet adjustment to get running right. I haven't lost a thing in terms of power and speed, and if anything it runs the best it ever has and the mileage is incredible for a larger bore, ported head, big duration cam engine. I will never stop loving the Fake Mikuni carbs. It's staying there forever.

Anyway, on to the real reason we are here. Redneck Engineering! A bit of steel strap for a muffler hanger and a pair of vice grips to hold the mid pipe in place.
(as always, if you want larger pictures, all of the images are linked)


The first problem with this particular exhaust is the mid pipe mounting bracket on the pipe itself. It sits too far away from the pipe, at the wrong angle, and does not center with the mount point on the Hawk at all.

My solution involves 2 heat shield mounts/clamps and a hinge reinforcing bracket from the hardware store (because it was $2 and weirdly perfect for this). Now I could mark my center and drill a hole. If you are curious about the stability of this mid pipe mount solution, it is incredibly solid. Surprisingly so.

This is the original bracket that comes on the mid pipe. If you are so inclined and can weld stainless steel, it would be entirely possible to simply cut off this mount, shorten the legs, and weld it back on in a better position.


I don't have a welder capable of thin stainless, so this is the hardware store solution.




Once I had the hole drilled, just a simple bolt and nut on the back side to hold it, and a large fender washer to help clamp the rubber isolator in the frame better. My last one got chewed up pretty bad because of the heat and probably my own over tightening the bolt and squeezing the rubber too tightly.

I will say this, the exhaust fits way better than the ebay system across the board. Plenty of clutch arm and engine case clearance. If my airbox was still intact it would completely clear the bottom with an inch of air gap. With my home brew md pipe bracket I was able to get the muffler alignment perfectly straight, where before it was putting most of the muffler over the tire.

The head pipe does't protrude out as far and stays tighter to the engine.


Look at all of that room.

[JerryHawk250]

What? No video or sound clip! lol That's definitely different. Looks good.

I picked up a new flux core welder a while back for just under $100. They do make a flux core stainless wire. I'm ordering a spool to test out. I have a huge lump in my exhaust on the Lycan I need to remove. lol I'm sure the welds won't be pretty but I have a huge heat shield that will cover it.

[Megadan]

Originally Posted by JerryHawk250

What? No video or sound clip! lol That's definitely different. Looks good.

I picked up a new flux core welder a while back for just under $100. They do make a flux core stainless wire. I'm ordering a spool to test out. I have a huge lump in my exhaust on the Lycan I need to remove. lol I'm sure the welds won't be pretty but I have a huge heat shield that will cover it.

I had considered a cheap small welder. I still might. Since this is an experiment at this point I don't really mind. Plus, I'm not kidding when I say that mount system is solid. It's not going anywhere anytime soon.

As for a sound clip. 2 things preventing that. I decided to re-do some wiring and eliminated the fuse block I installed, which required a re-do of some wiring and I don't have the right size ring terminal for my new fuse holder. Need to get one today.

The other reason is the weather. We are getting some spring time severe weather. Tornado threat and a chance for large hail, etc.

[JerryHawk250]

I'm really impressed with this little welder. So much better and lighter than my old mig welder. You can use it for Tig and Stick welding too. I see the price went up. If you have Prime, you get $30 off. https://amzn.to/4aCuMXK

[Megadan]

Originally Posted by JerryHawk250

I'm really impressed with this little welder. So much better and lighter than my old mig welder. You can use it for Tig and Stick welding too. I see the price went up. If you have Prime, you get $30 off. https://amzn.to/4aCuMXK

For that price I may just give it a try. Good enough to stick a bracket back on an exhaust after cutting it down to size. I saved that to my wishlist.

As for the muffler I likely won't be using this one for too long. The look is different, and in it's own way kind of cool, but I used it because I had it on hand from my last exhaust experiments. I am probably going to order one of these guys in the 440mm length, assuming I don't find my bike losing power with this exhaust.
https://www.aliexpress.us/item/32568...yAdapt=glo2usa

Or this Round bodied Yoshimura knock off (450mm).
https://www.aliexpress.us/item/32568...Cquery_from%3A

Or I can go silly and use one of these 570mm giants. With this set of pipes I can! That's the part I love, options.
https://www.aliexpress.us/item/32568...Cquery_from%3A

[JerryHawk250]

I was going to order one of the Yoshimura Knock offs for my Vulcan S. Now that I have the ST, I put the Vulcan S up for sale. I have a guy coming tomorrow to pick it up.

[Thumper]

Looks good. The curved megaphone follows the path nicely, fits.

That snug fit of the resonator against the engine will allow you a bit of room to clamp a custom heat shield if it poses a threat (!) It is tucked away, but might could use a shield.

I have seen builds here on this site that involve headwork and opening up the exhaust sytem to improve midrange torque (esp) and I've heard the phrase "willing" or revs easier too. I also hear of people struggling to make a larger bore carb work, unsuccessfully. It is the "go to" upgrade.

My OEM Youall carb on the Templar is very dependable. I do have it jet on the rich side. I should lean it out a bit for better running when hot, but it isn't really that rich. The primitive shim method can work nicely for the needle, and I didn't mind drilling out the airmix screwcap and extracting the float bowl screws. I really have no reason to replace that carb now until I follow through on porting, slight overbore kit (to 265cc), and get a pipe on there with a resonator. Then a better carb would be a good idea at that point.

[Megadan]

Originally Posted by Thumper

Looks good. The curved megaphone follows the path nicely, fits.

That snug fit of the resonator against the engine will allow you a bit of room to clamp a custom heat shield if it poses a threat (!) It is tucked away, but might could use a shield.

I have seen builds here on this site that involve headwork and opening up the exhaust sytem to improve midrange torque (esp) and I've heard the phrase "willing" or revs easier too. I also hear of people struggling to make a larger bore carb work, unsuccessfully. It is the "go to" upgrade.

My OEM Youall carb on the Templar is very dependable. I do have it jet on the rich side. I should lean it out a bit for better running when hot, but it isn't really that rich. The primitive shim method can work nicely for the needle, and I didn't mind drilling out the airmix screwcap and extracting the float bowl screws. I really have no reason to replace that carb now until I follow through on porting, slight overbore kit (to 265cc), and get a pipe on there with a resonator. Then a better carb would be a good idea at that point.

That resonator is a large cell catalyst. Or at least pretending to be one. The individual cells are rather large, so I don't see it being very restrictive at all, especially with the exit being essentially the same size as the catalyst itself. No bottle neck like the stock system.

It does actually have a decent air gap to the cylinder as well. My fear at first was that it would end up too close, but after making my mid pipe bracket ala Hardware store, it moved it away enough that I am not concerned about the proximity too much, but I do have a heat shield on the way, more to protect me and my leg than the bike.

Having basically played every mod game with this bike, I have come to the conclusion that the "ultimate" modded street ridden Hawk = Motocult kit and a VM26 "30mm" clone, and an exhaust.

The VM26 Clones aren't really any different than the stock carb other than the choke working backwards and the bowl has 4 screws instead of three. The key difference is the fact that they use Mikuni jets, and Mikuni jets are simply superior to Keihin. They function as a tapered metering orifice instead of a basic hole. That just seems to make them run better. Better than the PZ30, which is more or less the same carb.

Maybe I am giving up half a HP on the very top end by using this carb over my PE28FL or using something bigger, but most of the bigger carbs have fitment issues and become tempermental with tuning.

[XLsior]

Originally Posted by JerryHawk250

What? No video or sound clip! lol That's definitely different. Looks good.

I picked up a new flux core welder a while back for just under $100. They do make a flux core stainless wire. I'm ordering a spool to test out. I have a huge lump in my exhaust on the Lycan I need to remove. lol I'm sure the welds won't be pretty but I have a huge heat shield that will cover it.

Having used the Blue Demon branded stainless fluxcore wire during my 3" custom exhaust for my van. on much the same type of budget welder 140am 240v...


My only advice is get the thinnest stainless wire gauge. My welder needed to be cranked to 11... and I believe what is .9 wire settled up with a heavy bead though managed to penetrate...


pre heating the job would probably help...


But yes it will do the work it just wont look like a TIG fusion finish.

[XLsior]

Hmmm...


https://www.aliexpress.com/item/1005...80160.html?spm

[bigdano711]

Originally Posted by Megadan

That resonator is a large cell catalyst. Or at least pretending to be one. The individual cells are rather large, so I don't see it being very restrictive at all, especially with the exit being essentially the same size as the catalyst itself. No bottle neck like the stock system.

It does actually have a decent air gap to the cylinder as well. My fear at first was that it would end up too close, but after making my mid pipe bracket ala Hardware store, it moved it away enough that I am not concerned about the proximity too much, but I do have a heat shield on the way, more to protect me and my leg than the bike.

Having basically played every mod game with this bike, I have come to the conclusion that the "ultimate" modded street ridden Hawk = Motocult kit and a VM26 "30mm" clone, and an exhaust.

The VM26 Clones aren't really any different than the stock carb other than the choke working backwards and the bowl has 4 screws instead of three. The key difference is the fact that they use Mikuni jets, and Mikuni jets are simply superior to Keihin. They function as a tapered metering orifice instead of a basic hole. That just seems to make them run better. Better than the PZ30, which is more or less the same carb.

Maybe I am giving up half a HP on the very top end by using this carb over my PE28FL or using something bigger, but most of the bigger carbs have fitment issues and become tempermental with tuning.

Nice work on that pipe and something I would likely do since I am a non-welder. I got my JFG pipe pretty much ironed...errr...hammered out. To make clearance for the clutch thingie on the case. I foolishly tried to bend it while connected to the head and only managed to crimp the head gasket, so I replaced it with the MotoCult head gasket. Much thinner, so I think I'm getting slightly better compression.



I am finally getting the PE28FL dialed with both new mods: pipe/head gasket. Just got back from test ride after putting the 105 main jet in and she is MUCH peppier. Was accelerating into the wind in 5th gear on a gravel road!!


Why did you go away from the PE28FL? Better luck with Mikuni clone? Prefer that tapered jet?

[Megadan]

So, first of all, it is not a cat. I believe Thumper is right and it was some attempt to make a resonator or built in dB killer. I was purposefully a tad rich, and after over 30 miles of riding around town doing everything short of WOT (ok, I did it once in 4th gear lol) as I am technically still within "break in" for my new rings and cylinder. The "cat" never got any hotter than the rest.of the system. Not even slightly.

My Action camera batteries are all dead. Seems they don't like sitting at 0 percent for a few months, go figure. (Oops) so all I have is this clip from warming it up after the first start. The camera doesn't translate how loud this.is, even at idle. I ended up using both baffles I mention in the video to make it tame enough to not feel horrible conspicuous, and go deaf.

Short Video:
https://youtube.com/shorts/g9ODyDyC_...ueIznQsRZu-Dyo

[Megadan]

So, my opinion on this exhaust. Other than the minor fitment issues, it's a good pipe. If it is a cat, it doesn't seem to hamper the performance at all, even on my big bore, ported, cammed CG250. The larger pipe volume after the "cat" likely helps with that a little bit. What you gain is a better fitting exhaust system, with engine, frame, and airbox clearance as well as the ability to fit any 51mm inlet muffler your heart desires.

As for me, I just ordered this guy iin the 440mm length because it was less than 40 bucks with a "coupon" deal: https://www.aliexpress.us/item/32568...yAdapt=glo2usa

I also ordered this inlet baffle. I may not need it, but I really like the design of tit, and it as $5, so why not. https://www.aliexpress.us/item/32568...yAdapt=glo2usa

It lookslike it will do the job without being as restrictive as the other one I have. My main goal is to have the performance of an exhaust system, but without as much noise as the normal ebay system. I want to be a little less conspicuous... or I am just getting old.

[Megadan]

I did manage to find 2 of these exhausts for sale on ebay, if anybody has an interest. Obviously, some minor fab work required.

https://www.ebay.com/itm/224730570293

[Megadan]

Originally Posted by bigdano711

Nice work on that pipe and something I would likely do since I am a non-welder. I got my JFG pipe pretty much ironed...errr...hammered out. To make clearance for the clutch thingie on the case. I foolishly tried to bend it while connected to the head and only managed to crimp the head gasket, so I replaced it with the MotoCult head gasket. Much thinner, so I think I'm getting slightly better compression.



I am finally getting the PE28FL dialed with both new mods: pipe/head gasket. Just got back from test ride after putting the 105 main jet in and she is MUCH peppier. Was accelerating into the wind in 5th gear on a gravel road!!


Why did you go away from the PE28FL? Better luck with Mikuni clone? Prefer that tapered jet?

I like how the PE28 performed. I love the idle mixture screw beight right there.on the side of the carb, but airflow wise, the vm26 30mm and pz30 are still plenty of carburetor for these engines, even fully modded.

Why the vm26? Simply because once it's dialed in, it's good to go. Mikuni jets deliver fuel better due to their tapered nozzle design, so fueling is consistent, which just makes the bike idle and run better. It also means the economy is better. On my previous ebay exhaust, with the 292 cam, and Motocult cylinder and head, my average fuel economy just riding around normally was 65 to 70mpg. That's almost stock fuel economy with the same size sprocketa.