Yamaha TRX850 Enthusiasts Forum

My speedo cable is broken and I am wondering if when the speedo is not working does it impose a rev limiter of sorts. I did a search and tried to piece together what I found but it didn't seem to answer my question directly. Basically at 7000rpm it breaks up quite dramatically and sounds much like a spark cutting limiter and is very definite in it's cutting in.

cant see how.... sitting here with the bike in netural, i can give it a fist ful of throttle to 8500rpm no worries with no limitations and free revs... I have heard of some imported models having speed limiters placed in the speedo which is activated upon reaching a certain speed and i think from memory can be modified (something to do with a disc inside I think )

Yes the limiter cuts in at 7000 revs, cuts off the spark to one pot!, but its electrical!
However it works off a disc and you will find that as you have temporarily disconected your speedo its now limited in revs. (Believe it was to stop the Japanese hooligans getting around the limiter easily). Get a new cable and you will be back to de-resticted.

Dave E

Or junk the standard clocks altogether and the problem will never arise again!
Just physically make the connection in the wiring loom.
I don`t suffer with all the TRX`s electrical mullarkey as it`s bare bones and equipment streetfightered.

My bike's running a digital speedo and no standard gauges at all, with the original (import) loom intact and a UK CDI with the TPS disconnected- no restriction and it'll rev clean past 8500 and show an indicated 140 (the clock stops working after that!). I have had it running with no clocks at all, Japanese CDI and derestrictor box and it was fine then too.

The restriction on imports is in the speedo which is wired into the loom. The 'deristrictor box' is probably something as simple as a 100 ohm resistor.

Cheers, I knew there was a correlation. Might try the wreckers tomorrow if they are open.

There are three magnets placed in the speedo, one that is attached inline with the speedo needle and moves with it. Another placed at 0kph and another at 180kph.
So if you just try to disconnect the cable to get around the restrictor the magnet at 0kph still initiates the restrictor at around 7,000rpm. But inbetween the two magnets while the the neddle is moving ,the magnet on the needle has nothing to send a signal to so you can free rev until the rev limiter at 9200rpm.. (till triggered again on the speedo by the one at 180kph ) I pulled one apart that I had as a spare to discover the mysteries of why this happens..

Mincehead wrote:Or junk the standard clocks altogether and the problem will never arise again!
Just physically make the connection in the wiring loom.
I don`t suffer with all the TRX`s electrical mullarkey as it`s bare bones and equipment streetfightered.

..... and pictures magically follow