Newbie upskills, and upgrades GT250R Muffler

[disenfranchised]

I highly recommend a screaming demon pipe for Hyosungs. It only cost $300 including shipping. No-brainer to fit.

I ordered one last night.
Went for the irridium one just cause I like the look.

[WarlockNZ]

Just a note to anyone looking at putting a straight through pipe on the Hyo bag ..

I've been having a chat to Jon over at JFK adn he tells me that hes seen a lot of issues with the hyo from doing this.

The short story is that the rear cylinder runs too lean and causes damage ... if you want to put a straight through pipe on ... make sure you get your jets and filter adjusted to suit.

Especially if your caning the crap out of it.

[MattyP]

Just a note to anyone looking at putting a straight through pipe on the Hyo bag ..

I've been having a chat to Jon over at JFK adn he tells me that hes seen a lot of issues with the hyo from doing this.

The short story is that the rear cylinder runs too lean and causes damage ... if you want to put a straight through pipe on ... make sure you get your jets and filter adjusted to suit.

Especially if your caning the crap out of it.

What's the average price on this kind of work? I'm running the can at the moment and I'm TOTALLY in love with it. Warlock, I was the guy on the red 250r parked in front of you before we left for the cheesecutter ride.

[disenfranchised]

The short story is that the rear cylinder runs too lean and causes damage ... if you want to put a straight through pipe on ... make sure you get your jets and filter adjusted to suit.

Especially if your caning the crap out of it.

Any idea on how much use starts to cause the damage?
I was planning to bolt it on myself, and wait for the next service to get a professional mechanic to do the jetting thing.

Anyone out there been using a Screamin Demon pipe for a while without anything else being done? Had any issues?

[Pancakes]

Is the Screamin' Demon straight thru or just less baffled and bigger perf tube. I have a straight thru 2" pipe (not on the the bike daily!) and it is sooo fricken loud I doubt that any un-baffled ones are available. Totally unwarrantable, a cop would most likely stop you if you rode past giving it any cas at all. It is as loud as no pipe. I have a 1 3/4" less baffled pipe on mine and the shop said it would be fine. Warren from Virgin when I called about getting one done by him earlier said that he has done heaps and they don't HAVE to have a re-tune. It is never a bad idea tho and I'd always advise checking it's not too lean if you have the tools ( I have an EGO meter but need to tap a sensor in to my bike still cos it's carbied so doesn't come with one ). It does run noticably hotter with the straight thru pipe on as is pop's way more on the over-run. Also has bulk top end, just keeps on accellerating way past red-line, you'd need to balance the motor, do the valve springs and maybe the cams or just cam timing if you wanted reliability and any chance of making the most of rev's that are so far out of the bikes normal engine operating speeds.
The louder pipe I have on at the moment isn't quite as loud as the Virgin modded pipe and has no-where near the free flowing feel of the straight pipe so I can only guess without cutting it open that it still has a reasonable amount of packing and backflow restiction.

If it runs too lean it will run hot. Some of the things that can happen (depending on the weakest point in the chain etc, can really only be tested by trial to failure unless your a guru then your not tuning Hyo-bags your a race tech) would be first on my list hot exhaust valves causing the valve to melt or warp the stem and seize or shatter into the ignition chanmber. Detonation, melted spark plugs the list does on.

The more free flowing the pipe on these bikes the less low power and the more top end. They seem to run rich (most engines run a bit rich from the factory as a safety measure, the new sports bikes and performance cars are closer to ideal mixtures so will lean out with more airflow sooner) so get a pipe from someone who has done lots like Warren/Virgin or have it fitted by a shop and get them to note down the mix is ok for the pipe on your recept so your bike sounds a bit gruntier but don't go free-flow/straight thru cos then your look at a performance engine build and it's just not worth it.

[disenfranchised]

Is the Screamin' Demon straight thru or just less baffled and bigger perf tube. I have a straight thru 2" pipe (not on the the bike daily!) and it is sooo fricken loud I doubt that any un-baffled ones are available.

First thing I looked at when it arrived...and it's definitely straight through.

Was a bit of a bastard to fit.
3 of the bolts holding on the old muffler came out fine, but the last one (at the bottom between the pipe and the swingarm) had a stripped allen key socket, meaning it wouldn't turn, and also seemed to be rusted to the end of the exhaust.

I ended up having to cut the head off the bolt to get it off, which took several hours...poor tools, poor technique, etc..

Putting the new one on was simple though, and it really does sound good.
You can see a pic in the "Show us your 2fiddy" thread
http://www.kiwibiker.co.nz/forums/sh...&postcount=393

[Pancakes]

+1

Nice pipe! Crazy colours. Still waiting on a review of the twin disc upgrade too. You got the new master too a? Was it any different?

[Gubb]

Sorry that I neglected this thread, i've been stuck in Auckland for 2.5 weeks with no internet.



The pipe is straight through, and i've only had it out about three times since I put the exhaust on, i'm gonna get it re-jetted at it's next service this week.

Looked into aftermarket air filters, and haven't been able to find anyone that nakes one yet.

K&N and DNA don't make one yet, as the bike is not selling in massive numbers in the States (remember that if it isn't popular in the US of A, it isn't popular anywhere!)

Will keep you posted.

[325rocket]

heres what ive heard … don’t know if its true or not, feel free to comment …

a straight thru pipe isn’t ideal and can cause problems if you dont “rejett” to suit but you run a much higher risk of buggering things if you run a straight thru pipe and do change your air filter and don’t rejet.
If you just change the pipe your still quite restricted by the amount of air the standard filter lets in so you might be alright.
Put a different air filter in that flows more and all of a sudden you have a load more air and still the same amount of fuel. This is when you get problems with the bike running lean.

Please don’t take this as gospel as im basing this on my experience with turbo cars not bikes but I would think it’s basically the same principle but from what I understand bikes have a much smaller tolerance when tinkering with the exhaust etc.

Anyone in the know please correct anything incorrect here.

[Aa7]

Faaar out! that is nice! It really gets the V-Twin sound out of that small 250 doesn't it? lol

Aa7 here in KB has a GT250 with a similar muffler and his bike sounds like a Ducati Monster

Nah nothing as flashy as this for my communter hack but my bike is a monster with all the hassles lately, it doesnt just sound like one

Aa7 just took the baffles out of the stock muffler lol

Ssshhhhhhh!!!, they'll all do it now ahahahah Is your pipe the same as these ones carbacca if not what make is yours? your makes a nice sound thats for sure

I have heard a GT250R with the iridium Screamin Demon and it was alot deeper and nicer sounding. If i had the faired model i think that this is a definite upgrade that needs doing. if you run a commuter naked hack like me save your coin and just debaffle the original

[Gubb]

heres what ive heard … don’t know if its true or not, feel free to comment …

That's pretty much bang on what I read before ordering the pipe. I had planned to re-jet, and add the air filter, but as I couldn't find a filter that would fit, I am still going ahead with the re-jetting on Wednesday next week.

Will let you all know how it turns out.

[disenfranchised]

All this talk of problems does have me concerned a little bit.
I did email the guys who sell them, and they did say that it shouldn't cause any problems, but definitely recommended rejetting.

I've just hit 7,000k's, and planned to get the shop to rejet at the same time as the 8,000k service....I'm assuming that there'd be some savings in labour charges from having both done at the same time?

I commute 20k's every day for work, and each day the popping/spitting noises have been getting more noticable, so I'm guessing holding out on the rejet for another 1000k's wouldn't be advisable??

I'm still loving the pipe though.
Every time I start my bike I smile, cause it sounds so much more grunty than it really is.

Coming to work today I ended up behind a guy on an old Norton, and I'd have to say my little 250 sounded louder than his (probably a 750 single)

[Gubb]

Possibly it's something to do with your current jet set up, the popping in mine has been pretty minimal, and I certainly haven't noticed an increase in it.

Then again, you've done almost twice the mileage I have, perhaps the stock injectors are a little worn?

Dunno, just some thoughts. Was always planning on having the re-jetting done at around the same time for myself, and as you said, getting them done at the 4000Km service to save on labour.

[WarlockNZ]

You'll be looking at about $130 odd for the Jets (including Labour) at JFK .. I had mine done today and holy shit man ... those boys know there shit when it comes to Hyosungs ..

I'll be giving them all my business from now on .. here's a link http://www.jfkjetskisandmotorcycles.co.nz/.

Tell them Murray sent you ... LOL ... I may get a discount out of it ... ha ha

[YOUTUBE]eaqr8Dggb3o[/YOUTUBE]

[disenfranchised]

You'll be looking at about $130 odd for the Jets (including Labour) at JFK .. I had mine done today and holy shit man ... those boys know there shit when it comes to Hyosungs ..

Are you sure??...Their website makes them seem a bit confused

heh, I might give em a look tho...I've been using Red Baron for my services cause I bought the bike there.
Despite all the bagging they get on here for how much they charge for used 250's, their workshop department seems alright.
Will have to see how much $$$ they want to charge me.