tt250 exashst bolt on?

['16 TT250]

Had you shown a pic of it before running it I woulda warned you that it would melt the plastic. As for the bolt, yes it got too hot too.

[Jayman77]

Originally Posted by '16 TT250

Had you shown a pic of it before running it I woulda warned you that it would melt the plastic. As for the bolt, yes it got too hot too.

Hey I was not thinking very well

[SeerAtlas]

what about airbox clearance,melting?

[Jayman77]

Originally Posted by SeerAtlas

what about airbox clearance,melting?

Air box is free and clear I had to a just the cluch cable some but it freed to I was just a boon head with the license plate mount but it is fine itcleaned up and is no big deal but it was more than worth it

[PNWDualRider]

Originally Posted by Jayman77

Air box is free and clear I had to a just the cluch cable some but it freed to I was just a boon head with the license plate mount but it is fine itcleaned up and is no big deal but it was more than worth it

Did you have to drill out the flange to be larger or was it a perfect fit already?

[Jayman77]

Originally Posted by '16 TT250

It's the pulse air injection valve and has no relation to EGR nor does it in any way do what EGR does. It's not there for the cat either, but it can take some of the load off the cat and make it more efficient. Pretty sure it does nothing at heavy throttle and I've never heard of it overheating an exhaust system. It's called secondary air injection and it's there to introduce air into the exhaust to burn off any hydrocarbons (unburnt fuel) that made it past combustion in the cylinder. Most cars/trucks accomplish this with a pump, the smog pump, but on bikes it's done with pulse air injection, some cars also use pulse air instead of a pump. After the exhaust stroke there's a small pulse of vacuum created in the exhaust and this vacuum sucks a little bit of air through the pulse air valve. With an aftermarket exhaust some bikes will crackle or rumble on deceleration, blocking the valve supposedly cures that. I haven't had the problem with any of my bikes so I haven't messed with any PAI valves. The system doesn't hamper performance at all other than maybe a bit of turbulence in the exhaust port due to the hole, but disabling the system won't change that unless the hole is welded and blended to eliminate it's existence. Some people think that allowing air to enter reduces the vacuum in the exhaust reducing the positive effects of valve overlap where a vacuum helps the incoming charge fill the cylinder. The theory has validity until one considers that the time it takes for the pulse air to happen will likely be after the exhaust valve has closed. As far as I know the pulse air doesn't function at heavy throttle anyway, it has a vacuum hose and I'm pretty sure that's there to control when the valve should let air in, at times of high vacuum/low load. I watched a dyno run of a Hyabusa with and without the PAI and it didn't change anything. I believe on that bike the computer controls the valve and it's been said that it shuts off under load. A shot of chain lube did add almost 5HP taking it to 197HP at the wheel, don't ignore your chains people.

EGR (exhaust gas recirculation) allows exhaust to enter the intake during cruise operation to reduce the effective compression of the engine lowering cylinder temp. to lower NOX emissions. It shuts off under heavy load so it's not a power robber, but some people think that any emissions device robs power.

Cats also don't rob power if they're not restrictive, but everyone automatically assumes they are restrictive. BTW, I haven't noticed it mentioned but the cat on the TT isn't in the head pipe like the Hawk, it's in the muffler and visible through the outlet. It looks like the outlet could be cut open pretty easily to gain access to the innards of the muffler. Since it has the beauty cap the welding afterwards wouldn't have to be pretty. I suspect that just eliminating the puny outlet and enlarging it to the size of the hole in the cap would add a nice deeper sound and reduce restriction without doing anything else. One could enlarge the hole in the cap pretty easily if wanted to go even further. Efficient and quiet mufflers on a single are challenging. I've made a few mufflers/exhaust systems and the generator on my MH has been the most challenging one so far, but I finally nailed it. Using different lengths of rectangular tubing for the outlet did the trick, my theory at the time was to break up the frequencies and having differing size pipes apparently did it. I used rectangular instead of round to also break up the port noise frequencies, if I'd had two different diameter or shaped tubes Ida used them. That almost 40 year old clunker is quieter than my friends' much newer ones in their fancy rigs.

This post is exhausting I am not a genius mechanic and this is common core exshaust

[Jayman77]

OK this is hoe I did flange

Cut the top of on bolt hole and use good washers probably will check bolt often

[Jayman77]

The middle just bolted right up but to raise the muffler up I did this with a very strong clamp to pipe right under air box no frame cuts or weilds

[Jayman77]

Run muffler as far into pipe as you can and use stainless steal zip tie

You can bolt it through where the hand grip bolts to the frame but it will require some grinding and you would have to cut original mountil to be cut off did not want to do that

[Jayman77]

For now everything looks good and exshaust is not melting anything

I will look for a more permanent solution if it is necessary but it is good for now I am going to be at my friend shop later this week and I am sure the grinder and the weilders will make its way into the picture

Took it for a run and it is so different also top speed is one 68 it was 64 but the real difference is in the middle gears 2 through 4 pull like hell

[Jayman77]

Not to bad

[Jayman77]

This thing feels like a leaf blower put you hand behind factory exshaust and it feels like it it tring to push out a popcorn fart the pipes that lead to muffler are much bigger and the exhaust hole is big enough that you can almost stick your hand in it spark arrester is clearly visible not hangers required

Free and open exshaust that does not chock out your power

Thanks for all the tips and links to videos I watched them all and used some things from both and threw in a few of my own I hope this helps and if any of you guys do this and see something I missed please let me know

And please no noise from the peanut gallery about the melted fender I am the first one to pull the trigger on the TT250 SUPER MODS

[simonjester]

Originally Posted by Jayman77

This thing feels like a leaf blower put you hand behind factory exshaust and it feels like it it tring to push out a popcorn fart the pipes that lead to muffler are much bigger and the exhaust hole is big enough that you can almost stick your hand in it spark arrester is clearly visible not hangers required

Free and open exshaust that does not chock out your power

Thanks for all the tips and links to videos I watched them all and used some things from both and threw in a few of my own I hope this helps and if any of you guys do this and see something I missed please let me know

And please no noise from the peanut gallery about the melted fender I am the first one to pull the trigger on the TT250 SUPER MODS

Thank you for blazing the trail.

[moparrob]

Out of curiosity, would it be possible to affix the aftermarket canister to the stock header pipe? That would seem to avoid alot of the problematic mounting and clearance issues.

[Jayman77]

Originally Posted by moparrob

Out of curiosity, would it be possible to affix the aftermarket canister to the stock header pipe? That would seem to avoid alot of the problematic mounting and clearance issues.

The new one is bigger and has the bulge not sure what bulge is for but hey for 140$ I wanted it