Interesting Tboost problem

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naughtyG

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Since I really could not notice any difference whatsoever between Vboost and Tboost, I thought I'd recheck it's fully operational again.

Well it is, but not at 3000 rpm, instead at 9000 rpm (!?!)

I'm puzzled. In Off mode it's off, nice. In Vboost mode it opens at 6000, nice. But in Tboost mode it won't open until 9000. WTF?

Here's more weirdness:

- my bike is a 1986 (frame says 10/85) - and it definitely has the older TCI unit.
- according to the Yamaha Service Manual schematic, the wire colors for the coils should be 1 - Gray, 2 - White, 3 - Orange, 4 - Yellow.

But on my bike, it goes: 1 - Orange, 2 - Gray, 3 - Yellow, 4 - White

I can see the Vboost controller is monitoring the gray wire (#2), so I wired my Tboost piggyback to the white wire (#4).

What gives? Faulty Tboost unit? Should I try wiring it to #1 or #3? :ummm::ummm::ummm:
 
just got my t-boost and was going to install it this weekend, i guess you can try flipping the wires and see if that chg it or not. watch for it to open up the valves. sorry cant help more until i fiddle with mine.
 
esp since i assume the tboots controller 'halves' the signal. 9k is not an even mutliple of 6k?
 
I got nowhere yet. I email Thomas, the guy I bought it from on fleaBay. He replied saying there was nothing in the Tboost that could break or make it open at 9k, and asked how I was testing the operation.
I replied explaining how I watch the Vboost servo open in the 3 different switch positions, and haven't heard anything back from him since.

I'm really at a loss on this one - I don't want to pay another $40 to buy another one, so if anyone has any idea about how to test the Tboost components I'm all ears..

That or I might try to build my own - from what I've seen it can't be that expensive or difficult, and they have all the required components at Skycraft over here.
 
G - make your own as shown on the VMAXoutlaw site - that's what I did. It works fine & it's cheap. I still have most of a pkg of 3.9K ohm resistors I'll send you for free. Pick up a diode for a dollar & I know you have a toggle switch & wiring laying around. This way you know for sure that in the "off" position you're stock & in the "on" position you're boosting at 3K. Sometimes fancy gizmos bought on the internet don't work properly - I say build it "old school" ...
 
sounds like a plan...

hey, for those of you with tboost, or a home-made tboost, heres a question...

i noticed this weekend, when the bike is idling, if i switch from 6k or 3k nothing happens, however when i leave it at 'off' for a few seconds the idle drops a bit. nothing i could see with the tach, but i could hear it. anyone else seeing this? i have to imagine it has something to do with the signal being interrupted?
 
If you have a close look at the Vboost servo motor, when you switch to the Off position you will see it move slightly. That may be why your idle is changing.

When did you adjust your Vboost cable last? It should have a wee bit of play..
 
it very well could be that, i didn't investigate too much...

never have. i'll have the carbs off eventually and take a looksy. last i looked it seemed good.
 

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