exhaust install questions...

[Kenstogie]

so i am installing the below exhaust https://www.ebay.com/itm/Full-Exhaust-Muffler-System-Slip-On-For-Honda-CRF150F-CRF230F-2003-13-Dirt-Bike-/142262634887 on my Tao TBR7 and want opinions from the guys that know...

i know that i will most likely have to drill out the flange bolt hole to fit and put on some exhaust tape so i wont burn my leg

but wondered are these the only mods to make it fit?

as i have read quite abit about the install on hawks and some mention

---making brackets?
---needing a exhaust gasket?
---aren't there clamps for the different pieces that go together? (they are a very snug fit as is)
---anything am missing?

many thanks and cheers
ps (i have already re jetted to a 110)

[alex_in_az]

Here's how I did it, I cut and welded the center section pipe to allow it to clear the rear of the seat diagonal and removed the airbox. It sounds great as well, never even come close to burning myself on the header and the muffler portion doesn't get too hot to touch

[CHIMOT]

Great job! Adding an unrestricted filter u now r on ur own to jet the carb n maybe if ur lucky ur Piston won’t b running rich with excessive gas burning that left it black when u finally dismantle the engine when it won’t start.

I love seeing others going through the same mistake I went through in my younger yrs... amidst to it all, that’s how we learn right? Btw props on that extra extension bracket on the exhaust. Hopefully u don’t do real riding where u travel more than 50 miles a day. Trials n error.

[alex_in_az]

Originally Posted by CHIMOT

Great job! Adding an unrestricted filter u now r on ur own to jet the carb n maybe if ur lucky ur Piston won’t b running rich with excessive gas burning that left it black when u finally dismantle the engine when it won’t start.

I love seeing others going through the same mistake I went through in my younger yrs... amidst to it all, that’s how we learn right? Btw props on that extra extension bracket on the exhaust. Hopefully u don’t do real riding where u travel more than 50 miles a day. Trials n error.

running a 115 main jet, been riding for 42 years and this is just used for fun on desert trails that are local to me

[Megadan]

Originally Posted by CHIMOT

Great job! Adding an unrestricted filter u now r on ur own to jet the carb n maybe if ur lucky ur Piston won’t b running rich with excessive gas burning that left it black when u finally dismantle the engine when it won’t start.

What? Dude, most of us here run or have ran that carb and filter combination on bikes that have run several thousand miles with zero issue. The jetting setup on these bikes with different setups is pretty well known by this point. This isn't a website just filled with young guys that have never turned a wrench or owned a bike.

[Megadan]

Originally Posted by Kenstogie

so i am installing the below exhaust https://www.ebay.com/itm/Full-Exhaust-Muffler-System-Slip-On-For-Honda-CRF150F-CRF230F-2003-13-Dirt-Bike-/142262634887 on my Tao TBR7 and want opinions from the guys that know...

i know that i will most likely have to drill out the flange bolt hole to fit and put on some exhaust tape so i wont burn my leg

but wondered are these the only mods to make it fit?

as i have read quite abit about the install on hawks and some mention

---making brackets?
---needing a exhaust gasket?
---aren't there clamps for the different pieces that go together? (they are a very snug fit as is)
---anything am missing?

many thanks and cheers
ps (i have already re jetted to a 110)

The problem with these exhausts is that no two ever seem to fit the same. I have seen guys have to hammer the pipes to clear the frame, bend sections to try and clear the air box. Other guys have fit theirs straight on, no hammer or bending required.

I needed no bracket out back, but I did have to make my own spacer for the muffler so it would clear the rear tire. The header and mid pipe sections are just a slip fit and don't need a gasket. I would recommend at least using a bit of tail pipe sealant there though.

The best thing you can do is mount every section loose at first and get it all to align how you need it. Once you think you have everything in position start by tightening the header flange, then the mid pipe, then the muffler last.

As far as the gasket, yes I would get a new one. You can use Honda part number 18291-MN5-650 or any aftermarket equivalent.

It will be hard to see, but here is how my muffler is mounted. Notice the gap between the mount on the muffler and the bike, that would be the spacer I made at work.

No bracket needed in my install as well. The only downside is that the airbox would have just barely been touching it with the rear corner, but I had modified my airbox to clear in that section.

[Red Hawk]

Here’s some eye candy. These are on AliExpress for about $100 shipped. The header flange looks like it’s already slotted Hawk ready. The Welds look pretty good too.
https://www.aliexpress.com/item/4000381383377.html

https://www.aliexpress.com/item/4000058830435.html

[Kenstogie]

thanks for all the tips and esp Alex and Dan (the patron saint of china bikes)

so maybe it will fit just fine or maybe it won't...
luckily it is metal and will bend a bit and i can make a bracket or 3 if needed....

all a part of the fun

thanks again guys..... gasket and sealer ordered

[JerryHawk250]

If anything adding an unrestricted filter will make it run lean. But any way proper jetting will resolve any fuel issues. Just about everyone on here knows that.

[Wild Dog]

Originally Posted by JerryHawk250

If anything adding an unrestricted filter will make it run lean. But any way proper jetting will resolve any fuel issues. Just about everyone on here knows that.

That should be the case but i once put a cone filter on the stock carb, i rode the motorcycle for a bit, black plug.
Of course nothing that a rejetting couldn't fix.

[Megadan]

Originally Posted by Wild Dog

That should be the case but i once put a cone filter on the stock carb, i rode the motorcycle for a bit, black plug.
Of course nothing that a rejetting couldn't fix.

Did that motorcycle happen to have a CV style carb?

[JerryHawk250]

Originally Posted by Megadan

Did that motorcycle happen to have a CV style carb?

Now that would make sense.

[Megadan]

Originally Posted by JerryHawk250

Now that would make sense.

It makes the most sense, but I don't rule out other possibilities. Any change to the airflow characteristics can cause unforseen side effects. Some airbox designs are rather clever, being able to both filter with minimal restriction while also eliminating turbulence and creating a very high flow and high velocity intake charge at the carb inlet. Remove that and you would actually end up lean.

With that being said, in the world of most chinese bikes... they don't have that level of R&D behind them, otherwise they would cost more and not be based on 30 to 60 year old designs and technology.

[Wild Dog]

Originally Posted by Megadan

Did that motorcycle happen to have a CV style carb?

Yes, that one was a keihin cvk34 clone

[Megadan]

Originally Posted by Wild Dog

Yes, that one was a keihin cvk34 clone

That's my many years of carb tuning experience speaking when I guessed that one. CV carbs are a whole different ball game when it comes to changing anything about the intake system.

CV carburetors are tuned to function off of the pressure differential of the intake pre and post throttle slide to actually function correctly. Change one aspect and it throws the entire tune out of whack. The slide won't open properly, the fuel mixtures go all over the place, and basically there is trouble in the kingdom of stoichiometry. In very sensitive CV setups even running a high performance air filter can throw off the fueling quite a bit.

The upside to a CV carburetor is that once the jetting is sorted out they rarely ever need a jetting change to compensate for temperature or altitude changes unless dealing with very extreme circumstances. They are a very "set and forget" system which is great for OEM manufacturers, which is why most factory carb setups from the late 60's to the advent of EFI were almost all CV carbs.

In the case of our VM, PZ, PE, and PWK carburetors, they are purely mechanical slide carbs. The downside to these is that they have to have their jetting adjusted for temp and altitude changes rather frequently by comparison. The upside is that they work on a very simple principle of mechanical fuel induction, so they are rather predictable when it comes to changes in the system.