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Discussion Starter · #1 ·
Is there a rev limiter on the Speedmaster? I have a 2009 that I purchased in January and I seem to be able to rev well into the "red zone." This is not intentional, I know it is bad for the engine. My previous bikes all had a system that prevented over-revving the engine. Is there something wrong on my bike or is this something Triumph left off to save money?
Thanks
 

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My understanding is that there is a rev limiter on the speedmaster, but I do not know what the limit is.

Rev limiters do not necessarily match the red zone on the rev counter - the red zone is more just a visual thing to serve as a warning, then the rev limiter is an absolute cut off.

These motors will actually rev much higher than the rev limiter let's you go, so you'll be fine.
 

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Hitting the rev limiter using the throttle is no big deal, but if you over-rev by down shifting too far or something similar, you can actually push the engine past the rev limiter. This is very bad. Valves can hit pistons causing damage to both, among other things.

Basically, if you are just winding out the throttle, no biggie. If you over down shift and let the clutch out and the engine is pushed passed the limit, very bad.

The rev limiter is about 8000 for the 865cc engines, a little lower 7600 (I think) for the 790cc engines. The efi bikes can be remapped to adjust this with something like a Tuneboy and Pieman has raised it by adjusting the coils on non efi bikes.
 

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I could totally have those numbers backward regarding the 790 and 865.
 

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According to my '04 Service Manual, the 790 Speedmaster and America rev limiters are set at 7400 rpm--same as the 790 Bonnevilles.

The rev limiter setting will be very close to the advertised rpm setting; however, the tachometer on the bikes may not read that close.
 

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According to my '04 Service Manual, the 790 Speedmaster and America rev limiters are set at 7400 rpm--same as the 790 Bonnevilles...
IIRC 04's were all 790's, however the 865 BA's & SM's have different limiter specs (SM is higher).
 

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Discussion Starter · #10 ·
OK, I figured out the problem. The tach is reading incorrectly. I wasn't close to the redline. In fact, according to the tach this morning the bike was reaching 3000 RPM BEFORE I started it! :eek: After starting it and leaving it idling it would read over 4000 RPMs...

After the battery died (a whole different story in and of itself) and jump starting it the tach started reading correctly. A quick test on the way home showed that there is a rev limiter and it kicks in around 8000 RPMs.
 

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I suggest having your dealer check your bike's tach against a shop tach to determine if there is a variance.
 

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Thanks Mike. My tach is apparently not accurate then...
My tach must not be accurate either. Every time I hit the rev limiter it reads approx. 7400 rpm's and I have an 865 ignitor.
 

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My experience with the OEM rev counters on a dyno, is that they're accurate up to about 5,500rpm and then they lag behind. Where as the rev limiter cut off, at what ever speed it is set at, corresponds with the dyno rev counter exactly.

I would trust the limiter for accuracy over the OEM rev counter.
 

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Are there any aftermarket tachs available that are accurate? If my rev limiter is programmed right that means my tach is off 600 rpm's at 8000. I can deal with it but it would be nice to know the real rpm. Then again the correct speed would be nice too.
 
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