OzVMX Forum

Marque Remarks => Suzuki => Topic started by: ninjamk on June 05, 2013, 01:51:22 pm

Title: TM250 Stinger length
Post by: ninjamk on June 05, 2013, 01:51:22 pm: Hi Guys,
Im in the process of tuning my TM250 and am wondering what everyone has as the stinger length for their pipe? I know each pipe is going to be a little different but im just looking for ballpark numbers. I have the same pfr chamber as http://www.vmxunlimited.com/pfr-pipe-suzuki-tm250/ (http://www.vmxunlimited.com/pfr-pipe-suzuki-tm250/) except with a custom made stinger which is currently around 8in in length. I would appreciate any suggestions.

Thanks!
Title: Re: TM250 Stinger length
Post by: albrid-3 on June 05, 2013, 01:58:24 pm: 7 to 8 inches sound about right, then your muffler, which will slip over.
Title: Re: TM250 Stinger length
Post by: vandy010 on June 05, 2013, 02:02:00 pm: whatever the Internal Diameter is x 12 ;)
Title: Re: TM250 Stinger length
Post by: John Orchard on June 05, 2013, 02:02:46 pm: I don't know if it's of any matter, back in the day, my local dealer Terry Bryant (Bryant Suzuki) was building some real quick TM's, he felt that the stock pipes were designed to run without a muffler, so when a muffler was fitted it made the stinger too long.

Terry subtracted the length of a straight-through core muffler from the stinger and welded it on there, the end of the muffler finishing at a length where the expansion chamber originally finished (before the original muffler).
Title: Re: TM250 Stinger length
Post by: Lozza on June 05, 2013, 03:07:48 pm: Makes no real difference
Title: Re: TM250 Stinger length
Post by: jerry on June 05, 2013, 03:35:34 pm: Lozza probably right but maybe estimate the length of a stinger from a 72-73 RH250. At. Least it will look good. J
Title: Re: TM250 Stinger length
Post by: SON on June 05, 2013, 04:38:45 pm: Quote from: ninjamk on June 05, 2013, 01:51:22 pm
Hi Guys,
Im in the process of tuning my TM250 !!!!
Tuning it for what??

Bottom End / Mid Range / Top End
What other modifications from stock?
Title: Re: TM250 Stinger length
Post by: ninjamk on June 05, 2013, 11:59:51 pm: Thanks guys.
I would like to tune it for mid/high, as I would assume that is what stock porting will allow. after the stinger I have a short 5 1/4 inch long muffler that has a ID that is larger than the ID of the stinger. Everything else is stock except for 34mm VM and foam uni filter.
Title: Re: TM250 Stinger length
Post by: Davey Crocket on June 06, 2013, 08:27:59 am: One thing to consider is the noise it will produce....you don't want something that is going to annoy the crap out of everyone.....you need something 10 to 12 inches long at least.
Title: Re: TM250 Stinger length
Post by: Hardex on June 06, 2013, 08:59:18 am: I have an original TM250 muffler for sale but is missing the insert call me on 0417349457 if your interested
Title: Re: TM250 Stinger length
Post by: SON on June 06, 2013, 01:14:59 pm: RH 73 Unsilenced Stinger is 195mm 19mm ID
Title: Re: TM250 Stinger length
Post by: albrid-3 on June 06, 2013, 02:22:36 pm: (http://i914.photobucket.com/albums/ac346/albrid-3/SuzuliTM001_zpsbfad46a1.jpg) (http://s914.photobucket.com/user/albrid-3/media/SuzuliTM001_zpsbfad46a1.jpg.html)
This is my Tm 250 L, original pipe.
Title: Re: TM250 Stinger length
Post by: bazza on June 06, 2013, 02:47:38 pm: just buy the beaten up RH one on e/bay.....only $ 3K
Title: Re: TM250 Stinger length
Post by: TM BILL on June 06, 2013, 02:58:10 pm: Quote from: Davey Crocket on June 06, 2013, 08:27:59 am
you need something 10 to 12 inches long at least.

Joan your bragging again ;D
Title: Re: TM250 Stinger length
Post by: Lozza on June 06, 2013, 05:26:22 pm: Quote from: ninjamk on June 05, 2013, 11:59:51 pm
Thanks guys.
I would like to tune it for mid/high, as I would assume that is what stock porting will allow. after the stinger I have a short 5 1/4 inch long muffler that has a ID that is larger than the ID of the stinger. Everything else is stock except for 34mm VM and foam uni filter.
Tuned length of the pipe is what the engine responds to the stinger length is more or less irrelevant. Both for perfomance and noise, diameter has the biggest effect.
Title: Re: TM250 Stinger length
Post by: ninjamk on June 06, 2013, 11:22:02 pm: Thanks Lozza, what is the correct diameter? I haven't measured it in a while but I want to think mine is 1 1/8 in.
Title: Re: TM250 Stinger length
Post by: Lozza on June 07, 2013, 10:45:12 am: No "correct" diameter but 28mm is on the large for a 250. Diameter is down to how much your piston can handle. Heat in the pipe is down to compression and advance .............etc etc etc ;D Smaller stingers favour high rpm, but I wouldn't go lower than 26mm
Title: Re: TM250 Stinger length
Post by: ninjamk on June 07, 2013, 12:21:28 pm: Well, I measured it up and its at 25.2mm. Am I safe to run it that way? Jet on the rich side, retard the timing? I just want to make sure the pipe is good before I fine tune the jetting.
Title: Re: TM250 Stinger length
Post by: GMC on June 07, 2013, 02:16:59 pm: 25.2 will be fine, it's not that critical.
Of all the dimensions in a chamber the length of the stinger is the least critical (within reason)
Stinger diameter is probably the next least critical (within reason)

I would say you have a window of 23-26mm diameter for your TM.
and around 200 -400 long for a stinger.
Outside of these dimensions is getting outside the norm.

Most 250's would run around the 1 1/8" OD stinger which equates to aprrox. 22 to 23mm ID depending on wall thickness