As the throttle position sensor isnt plugged in on my t/cat engined 3tj the tacho does a sweep to 3000rpm every few seconds.i thought i could live with it but its driving me nuts.im using the 3tj loom with the t/cat ecu spliced into it.ive tried a few things to stop it but to no avail any hybrid owners have any sage words of wisdom on the subject.i do have an acumen rev light i could wire in but you have to hold the revs at a steady 4000rpm to program it which is impossible to do.any tips would be much appreciated.

Tim had hassle with a rev counter.

I don't know ... but ... change the CDI for a FZR600R one ???

Had considered that but the t/cat has a different bore and stroke so it would be timed differently.im really at a loss what to do as it really niggles me now.i tried connecting the t/cat tps wires up but to no avail as you can only now adjust thr tps by dropping the motor as the tps unit sits on the end of the right hand side carb and is only a few mm from the right hand frame spar.i tried shorting the tps wires but still the 3000rpm tacho dance!!

i'm sure you've checked it but its not the fuel sender issue that i experienced on the fzr600 loom? Without it being wired in, the tacho would swoop round every few seconds.

The thundercat carbs have a couple of small differences, however the main body looks pretty much identical to the fzr600's.

They will definately sit in the fzr carb rubbers, i was planning to plug em in at some point and see what difference they make. However mine need a good clean before i can attempt it.

I'm guessing they will have bigger jets over the fzr's as they run a pressurised airbox.

The thundercats main jets are 155,pilot air jet 140,pilot jet 38,i think from memory that the outward body appearance is the same but the internals are quite a bit different from the fzr600 foxeye carbs- the t/cat carb model is keihin cvkd36
the fzr600r foxeye carbs are keihin cvkd34/4 with 118 main jets,pilot air jet 100,pilot jet 35.
hope this helps.no its not the fuel sender tacho dance, the t/cat ecu lets you know when the tps needs adjusting or if theres a fault with it by sweeping to 3000rpm.i really need to put the t/cat loom on but i dont want to pull it apart as its now running so well and dont want the hassle of rigging up the 3tj lights,brake switches etc to the t/cat loom.the loom is destined for hybrid2 but i need another t/cat motor since the fzr600r gearbox shat itself in hybrid one.i may even sell the powder coated frame, swingarm,subframe and with the r1 front end and r6 shock yet to make way for something else yet as i havnt made much progress with it and i now need another good t/cat motor to put in it.we will see

Hi, im pretty sure the fzr600r cdi will work on the thundercat engine. I think the only difference is the extra plug on the thundercat cdi for the tps. The bores and stroke are the same on the fzr6r and the tcat, its the earlier genesis engine that has smaller bores and a longer stroke. If you are using the thundercat carbs you could just connect the tps to the cdi. I havent actually tried a fzr6r cdi in a tcat but if you want i could whip mine of and try it on my friends tcat to see (and save you the expence if it wont work).
Alternatively, as you have said, you could fit another rev counter such as a scitsu or acumen.

I am such a just swapped the t/cat ecu for foxeye fzr ecu and no dreaded tacho dance-i could have done this a month and as half ago.dont know why ,but i was convinced the cat had a different bore and stroke to the foxeye. THANKYOU THANKYOU THANKYOU all for enlightening me,im off to eat a large peice of humble pie!!!!!!

To close to the problem

cagiva996 wrote:The thundercats main jets are 155,pilot air jet 140,pilot jet 38,i think from memory that the outward body appearance is the same but the internals are quite a bit different from the fzr600 foxeye carbs- the t/cat carb model is keihin cvkd36
the fzr600r foxeye carbs are keihin cvkd34/4 with 118 main jets,pilot air jet 100,pilot jet 35.
hope this helps.

How come the thundercat has a much bigger main jet than the FZR600R?