RMS 185A HOP UP

[TT5 Matt]

hi all
got given a going  ts185 and 250 both a models and a week after buying a rms125 frame off ebay i thought why not a rms185 for a neat little trailie to buzz around the hundereds of 2 wheel tracks starting from the outshirts of town and going hundereds of kms in all directions,
want i would like to know is whats the biggest carb you can fit to the standard inlet rubber without it splitting[im thinking 28mm ts 250a carb] and open out the inlet port ,squeze up the mixture with a head surface on the lathe and clean up the transfers and exhaust ports,does anyone got a design for a pipe to suit the rms chassis with a 185 or will a cr125 pipe fit?

thanks TT5 Matt

[cyclegod]

Heres some pictures of the used "Hop-up" kit pipe for my TM/S 185

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[cyclegod]

Heres some pictures of the used "Hop-up" kit pipe for my TM/S 185

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[cyclegod]

And a NOS pic...

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[cyclegod]

Don't forget to upgrade the ignition to a TM125's setup (CDI,Mag and flywheel), it bolts straight on and uses the same ignition coil too

[TT5 Matt]

hi Cyclegod
nice pipe! is that a tm job with a cut and shut and is it for sale? thought about the lightweight sparks but i want  to put RTA on this bike[probly as a ts185 than do the swap]but yeah it would get it to rev out quicker,a close ratio rms box would be good also for abit more squirt but wont do that till i remove the left hand slinger plate for premix use

TT5 Matt

[cyclegod]

Its not a TM pipe but a genuine "hop-up" kit pipe meant for the 1972 TS185, it's longer in the middle than the TM and sits slightly further back but fits the frame perfectly. A circle-f cr125 pipe might fit but you would need to lengthen the middle section to suit the 185

[Doc]

Lightening the 185 standard flywheel will have fairly dramatic affects on the power delivery also and you can still retain the lights/charging circuit 

[pokey]

The A models were a bit different to the previos RJKLM.. The A's were a transition on the way to the ER series so Unsure how an old pipe would perform on it or even fit the barrel.

As for bolt on performance its a case of suck it and see as not many A model 185's  found there way over here so performance bits if any would be rare..
if you want to use her as a traily dont worry about getting revs out of it as the torque will carry you anywhere and if you modify to get revs you loose torque.

Id leave the slinger plate in and run the oil pump. They just dont stuff up so why play with something that works and works well?

Wish I knew more about the A models and compatability but  never seen that many around to play with even when they were all shiney and new.

If the exhaust port exits at the same angle as the previous years and you want trail use out of it look for a bassani or TORQUE brand pipes.
 Both Up pipes that were made for the 185 series.

[TT5 Matt]

hi
yeah i used a bassani up pipe on my 74 L model with good results but it would be hard with an rms chassis running an airbox ditto for making/mounting an oil tank,the previous owner remove the oil tank and run premix and the l/hand crank bearing was squilling badly just after startup so it will need replacing and do a close ratio box conversion..

Matt

[pokey]

For an oil tank if you were to go down that road, a brake master cylinder resovoir does an excellent job and can be strapped to frame (thankd Doc).

  yeah seeing you have to operate on the squeeler anyway its no drama to pop the spinner off.

Ignition wise try yz80 electrics, nice curve on those things.

I have a Torque pipe that im thinking of playing with  but will most likely get a custom made down pipe to suit all the engine mods

[Lozza]

Hey pokey, I still have an early 185 barrel and piston of yours here.I'll have access to a bike soon so pipes galore for 185's.Best news is the transfer port problem can be fixed

[pokey]

Good news indeed Lozza. Hopefully soon i will get my finger out and get that bottem end down to you .

[TT5 Matt]

thanks Doc for the resovoir idea

Pokey just change the cdi or the full system [ive got yz80j complete or rm80 cdi] ?

and have you got some pipe dimensions so i can have a go at making a pipe at tafe under the teachers guidence after i make a small set of rollers

TT5 Matt

[pokey]

Aaahhh Dimensions.  They be the realm of "The Insitute"
 Sweet talk Lozza Matt, he knows more than any human should know about that stuff. If he dont know he knows who does know.

Have had multitude of talks with Loz and what I thought were performance ideas seems they had limitations, yeah they work but  minimally.
 To put you in the pic My LONGoing project is a 74 TS 185 that on theory should kick some cr250 ass and smile cheekily at the open class bikes and thats legaly using the info from  "The Institute".
 
 Pipe dimensions depend on your gas flow  and again "The insitute"  has it cornered and cornered well. Set the ports up and then get a pipe to match your bottom end and barrel so it works. Mr Jennings  has  some good reading on 2 strokes , is a link on one of the forum pages and you wont go wrong with him.

 Dont shave the head, seems you lift studs and its a long push back to the pits