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Been out today for the first time since putting bike together it uses a mychron 4 2t rev counter & egt plus cylinder head readings can anyone say what aprox
readings should possibly be
thanks

Has anybody any thoughts on what Temp a rally going rb/ts1 should be running at with an egt .


Mab

Hi to all interested,

Richard Fellows who purchased back in June 2008 the first RB250 (6T Cylinder Kit) tuned by me at Taffspeed, was giving 32bhp @ rear wheel @ 8,500rpm with the enging capable of running to 9,400rpm where it stopped revving. It gave 20bhp @ 70mph in 4th where it was ridden most of the time going to rallies.
This was fitted with my own Mychron 4 2T unit & was the scooter I took to the Isle of Wight that year; it was a Matt Black GP scooter that I let a few interested scooterists ride.

Anyhow the engine has been run using the cylinder head plug temp thermocouple, giving readings between 120'C & 180'C, using NGK B8ES plug dependig if at a constant cruise or excellerating hard up into the higher rpm's.

This motor has still not been apart in the time & has been sprinted & done a 15.87 sec 1/4mile terminal of ust under 80mph & has a top speed of 85-90mph sitting upright! During the 1/4 mile sprints the plug temp never went over 140'C so room for improvent with a higher comp ratio for sprinting, however it is still Richards Rally going scooter.

If the exhaust probe was to be fitted I would not want to see a reading over 480-500'C to be showing when riden at high rpm for long periods on 95 octane unleaded fuel. This leaves a saftey marging of around 50'C to warn of impending disaster!

I trust this has helped,

Ian Frankland
Taffspeed

my rb230 has a cht and egt gauge
tickover cht 90 egt 190 at 1100 rpm
50mph cht 140 egt 450

65mph cht 180 egt 650 will go this high an more if held at this speed

never seen the cht go above 190 was told cht was ok upto about 200,
egt was told could handle 700 as the piston temp was prob 50 less than the egt reading and a piston could handle upto 720 ish
vapour rev indicates at 65 mph is 8500 rpm

am just about to put a cam lam power jet on without changing the carb setup an see if i can get it to only come on when the egt spikes, lookin at the way they work i think i can cut the lenght of power jet so it comes on in a certain throttle setting ie half throttle 60 mph when it starts to get really hot and cool it down with load petrol out of the power jet, anyone got any thoughts on this ?
gaz ash
knobspeed

Why not just richen up the midrange a tad?

cause the tm carb is limited to what u can do the setting i hav is the only place i can get with it were its rideable

Hi Ian, I hope you're recovering well!

I really wish I could have shelled out the cash for one of those and I gave it a helluva long consideration! That's about perfect for a road going fast scooter.

Hi thanks to all that have replied,firstly I would also like to wish Ian a speedy recover (i used to race with Dave Webster,malc, Norrie & Guy topper many years ago)
The bike was runing at 620 egt & 140 cht. But this is all new to me did not have sencors 27yrs ago,When I asked Guy he thought 620 was a bit high so this is
why i put post on. I have a TMX 35 which runs 2 power jet one of which i turn on at the light switch when i want to add more fuel at half to full throtle,much the same way as the race guys do ( its not a cam lam one)
sorry for my spelling and grammer
Thanks

hi could u giv me more details on your powerjet that u turn on with switch

thanks

Therein lies the problem.