Carb and muffler advice

[limbimtimwim]

OMFG SO FREAKIN' LOUD AND SOUNDS f*&^ING AWESOME. MY EARS RING WHEN I STOP THE ENGINE. SORRY WHAT? I AM SHOUTING?

Well, loud on the bike anyway. I asked a mate to have a listen why I tried to make as much noise of possible going past (Sorry Island Bay residents) and he reckoned it wasn't going to get me a ticket.

And it has turned my little pops of backfire into something I really notice now. But the next step is to sort the carbs anyway.

Yes, there is a real performance boost from it though, doesn't seem to have destroyed the bottom end of the rev range either. And the bike will have lost several KGs of mass. Popped a mono by accident _while moving_ don't know if that was just my clutch dropping bravado or that extra 2HP I just released though :-) .

Fitting was a snap. it came with instructions, which basically said "cut here" and a hand drawing with 'collector box' annotation with an arrow. My experience went like this:
Saw off old muffler 50mm from the collectorbox. I marked where I should be cutting with a vivid marker. Did it with hacksaw in about 15 minutes, and I managed to cut it straight and clean, which was good. I was suprised to see that the pipe after the collectbox had baffling in it, Honda didn't just put the baffling in the muffler. Tricky..
Put muffler goop on that last 50mm after the collector, slide on muffler, realise not enough goop, take off muffler, more goop, put back on muffler, tighten retaining strap around engine end of pipe.
Fit hanger, which lined up bloody *perfectly* with the the place it was supposed to, the hanger even had a little twist in it at the correct angle to make it easy.

I was really impressed with the appearance of the muffler. It came in a box crammed full of newspaper for shipping, so it was well protected from those with ham fists. It feels rock sold, and is and is very shiny. The outer coating and the carbon fibre trick the eye a little, making seem 'deeper' than it is. The outer carbon mat (The only one I can see..) is in one piece and has been layed straight, along the length of the muffler. The engine end is made out of stainless, including the retaining strap, the bolt looks a little cheaper though. The noisy end is made out of alumilionoinnnmnmn and so is the hanger, both lovingly polished. All the welds look very tidy. The hanger had the nice touch of having a thin coating of rubber on the inside, lessening the chance of scratching the muffler when positioning the hanger. I imagine it might reduce a nasty vibe or two as well.

If you are thinking of something fruity to replace your silly noise reg muffler, take a look at www.rooracing.com and give Alex the friendly pom in Perth a call. Not the cheapest, and once it gets here Customs grab it and make you pay GST. Helpfully, the exchange rate to auzzie dollars is pretty good at the moment. But I don't care how much I spent, I am so happy.

Oh yeah, it sounds absolutely amazing. I was giggling like a school girl for some time. I took 3 or 4 trips through the Seatoun tunnel. Then a repeat effort at the Northland tunnel, shifting up and down, revving it hard or just idling through to enjoy the different sounds.

A 250 shouldn't sound this good. And I'm smiling like I just got a new bike.

I really really want to sort the carbs asap now.. But I'm waiting on that new needle.

[TwoSeven]

Make sure you wear earplugs with that end can - even on idle. Mine ran at 90db idle and 140db at 8-10k rpm. I had hearing problems even just warming the bike up - That ringing is your ears fooking up (its what causes tinitis).

[limbimtimwim]

Make sure you wear earplugs with that end can - even on idle. Mine ran at 90db idle and 140db at 8-10k rpm. I had hearing problems even just warming the bike up - That ringing is your ears fooking up (its what causes tinitis).

I know :-). I have plugs, and I will be wearing them from now on.

[limbimtimwim]

All done, I'm very happy.

I took the carbs off last weekend and took them to Boyle Bros to get them cleaned. $30, that has to be worth it since I imagine all the chemicals and crap would end up costing me that much to do it myself, and then stink. I also got them to install the main jets, since I got confused when I took off the float bowl covery thingamy. Removing and fitting the carbs wasn't hard, just a bit fiddly. Honda were not thinking of my fat fingers and hands when they decided on the positioning of the main fuel line from the tap on the tank. Bastards.

Anyhoo, I fitted them this morning, and started it up. First problem, it was running on one cylinder. Of course, it was just my dumb self not reconnecting both the ignition leads.

Then it ran fine, with a tiny backfire that usually clears up as the bike heats up. But in this case, it did not, and the backfire got worse.. and worse.. and worse.. I got pretty worried and came back home. The bike felt fine, just as long as the throttle was more than 1/5 or so open. I adjusted the idley mixey screws and that problem has gone away.

Had another ride, much better. The bottom very bottom of the rev range is no better than before, but the bike now accepts full throttle with no hesitation anywhwere in the rev range. Once in the midrange, it revs out towards the top end with a tad more urgency than it used to.

The engine feels better everywhere, where once I would go into a corner in the wrong gear (ie, one two low) and would be stuffed, now I can accelerate through a corner better than before. Which is great because the VTR only has 5 gears.

Changes done:
*Replaced air cleaner (Standard Honda part.. :-( )
*Replaced standard Honda muffler with Roo Racing carbon fibre loud thingamy
*Main Jets changed to #118's instead of standard #115's
*Diaphramy Needly thingys replaced with adjustable ones, with clips currently on position 3.
*Carbs cleaned
*Idley fuel screw set at 3 turns out from closed. Honda puts it at 2 1/8 out and the carb kit makers suggested starting position of 2 1/2 resulted in nasty backfire at idle and with closed throttle with many revs. 3 turns out from closed seem to work well, it doesn't feel 'soggy' when opening the throttle. Backfire is elimiated.

What I didn't do was enlarge the main air jet. Factory Pro provided a drill bit for this perpose, I decided against doing this as it would be a rather permanant change to the carbs. If I one day get my hands on another set of carbs, then I will drill those out and see if it makes a difference. Factory Pro reckon the bike will 'hit harder' at the top end with the enlarged hole. I think they are trying to lean out the engine just a tiny bit so that it's on the verge of detonation when the revs are way up there. Me; I'll play it safe for now thanks.

It's hard to attribute the improvement to any one alteration I have made, but they have all added up and it all works better now. They have all been pretty minor but my VTR is better for it now, hurrah!

I'm not woried about pulling my bike to bits anymore, it's fun and I learnt stuff.

Now to find a small enough turbo..