Yamaha TRX850 Enthusiasts Forum

Gday all!

First post on here, and I'm sure you've all heard it before, someone asking for advice on carbs and exhaust systems.
I've been trawling through here for a while now slowly gathering information and insight and chasing parts down online. Basically what I'd like to do is make my t-rex breathe easier and get a bit more poke into the bargain without cracking my cases apart or pulling barrels and head off etc. I've sussed out a Mikuni TDMR40 kit and and an exhaust system ( http://www.projection-components.co.uk/ ... -168-p.asp ) Just bolt on fun and go fast bits.


Just wondering if anyone has any experience with either of these bits of kit, (in particular the headers) and can offer any advice as I've found no real substantial information, just pixellated dyno graphs with pretty numbers. Also, if anyone has any local (Australian) alternatives, I'd be absolutely stoked to be able to keep my money over here and not accidentally send it to some Nigerian prince.

tl;dr: I'd like to make my bike go faster and I'm scared to buy things without knowing how well they work first.

Cheers!
-Gareth

Welcome Gareth,

I haven't used any of the bits you mention,sorry. Most seem to favour Keihin Fcr 41's as the performance carbs of choice, I can personally vouch for their reliability and performance enhancing characteristics .
Everybody using them seems happy with Kayla's (Projection Components) exhausts. Staintunes seem to be very popular in Australia.
I'd recommend Fcr's as a first step and see how you get on. If carbs alone don't give you the power lift you seek, then you should be looking at cylinder head, cams, big bore and exhausts. Probably as well to do the big bore,cams and head at the same time,while the top end is in bits.

Mark

Cheers mate!

Should've mentioned I have a set of Staintune slip-ons stuck to a set of (now dented) headers. I briefly forgot what bike I was on and took a footpath shortcut around some traffic and knackered the underside of the headers on the kerb. I could easily pull the dents out with some strategically applied heat and a slide hammer, but the excuse for new big bore headers is too tempting. How do the FCR's go on a stock head? I'm aiming to keep the modification strictly to the outside of the engine, as the bike has 16,000km on it and I can't justify pulling the thing down JUST yet
Not looking for insane power, just a touch more with more in the right places is all

Cheers for the quick response!

-Gareth

Geez, mine had 16000kms on it when I bought it, but that was 11 years ago. Now it has 115000kms

Bob

There's plenty of local exhaust manufacturers he in Oz who can build you what you need. Most av around $600/650 for your headers and link pipe. I had some built local at Pipemasters large bore 2 into 1. Tranzac are another local here in brisbane and there's a one or two more if you surf the web who can give you what you need. I had found 87 hp at the rear wheel with FCR's and 2 into 1 at 100,000km . Which is another 11hp compared to the factory specs of the showroom floor.

Yeah I was pretty stoked when I found it, though I was spoiled for choice as there were quite a few for sale at the time. This one ended up being the most expensive but the lowest K's, the next being not far off at 23,000. And cheers, cobba! There are a fair few around that'll do it but what I was wondering was if there's any particular shops that you were aware of that'd do a better job than most Thanks heaps for the info guys, 2-1 seems like the way to go. I'd miss the wheelbarrow look from the rear though haha. Are there any serious flow/port size mismatch issues that anyone has ran into? Or is it a case of whack on the FCR's and go for it (after jetting of course). Excuse all the questions, I'm just too damn curious!

FCRs will give more of everything, everywhere. They're by far the best (£ per bhp) thing you can do to a TRX after sorting the suspension out and I'm the person selling those 2-1 headers...

It all depends on what you want the headers to do. Having a two stage pair of headers or just keeping the std header diameter or goin for larger size right from the start which robs you of some of that midrange punch out of the corners and the can and outlet choice. I've just got off the phone to Ken at Megacycle in Melbourne to get another can made with a larger 57mm outlet for the Akrapovic headers I have.

Again, thanks to everyone for all the help! Kayla- cheers for the input, plus those headers look pretty horn! might end up lashing out on a set FCR's seem to be the way to go, more kits are available for them than anything else. It's just a matter of finding a distributor in aus for a decent price, I've thrown out about a million emails asking different guys, we'll see how it goes! I bought the bike with bluespots, rebuilt rear shock and valve emulators in the front end and set up for my weight. I also bought a set of dunlop sportsmarts (sticky as hell) and I've gotta say this thing sticks to the road like the proverbial turd to the blanket and handles like its on rails. With the flatslides does anyone get a bit of a flat spot if you reef on the throttle? Or does a properly sorted accelerator pump work out all the kinks in the fuelling?

Frunkehbohnze wrote: With the flatslides does anyone get a bit of a flat spot if you reef on the throttle?

Properly set up - no.

Thought so. Seen a few videos with people revving the poor guts out of their bikes with a massive flatspot, it's a shame people don't take the time to do things properly

Kayla wrote:FCRs will give more of everything, everywhere. They're by far the best (£ per bhp) thing you can do to a TRX after sorting the suspension out and I'm the person selling those 2-1 headers...

You`ll never be a millionairess pal.

Mincehead wrote:

Kayla wrote:FCRs will give more of everything, everywhere. They're by far the best (£ per bhp) thing you can do to a TRX after sorting the suspension out and I'm the person selling those 2-1 headers...

You`ll never be a millionairess pal.

I'm happy to make a living, not a killing

Not often heard these days where motorcycles are concerned, good on ya.