Triumphrat

tjwood

Hi,
I've got a Boyer electronic igniton unit fitted to my almost finished 1970 T100S. Unfortunately I bought the wrong one - I got one for an Enfield Bullet by mistake. Boyer supplied me with the connection details to use it on my Triumph and the bike starts and runs but I've been informed that the ignition unit has a rev limiter set at 7000rpm (to protect the Enfield engine). The things is, I'm not sure what sort of speed 7000rpm will give me so I'm not sure whether it's going to be a 'problem' or not. So, before I shell out another wad of cash for the correct Boyer unit I thought I'd just ask to see if anyone can give me the speed info.
Thanks.
Tony

DerryUK

It will be faster than 70 MPH <s>.

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DerryUK

'69 T100S being rebuilt - very s-l-o-w-l-y
VFR800 VTEC

JohnA

7630rpm should = 100mph with 18/46 gearbox/rear wheel sprockets. If your sprockets are different to this, obviously the speed/rpm figures will be different.

I think the main question should be whether you're ever likely to want to rev beyond 7000? A lot of people seem to keep a long way below that kind of figure on 500s, 650s & 750s. Not saying this is 'right', just that its apparently quite popular.

daturat100r

Change the black box for the right one, be a cheaper than a whole setup . You dont want to go strangling a 500 ,they are cammed to rev though not recommended to use 7000+ all the time can be useful (and fun)on hard charging runs

Mr.Pete

As I recall,max power happens at about 7250 rpm.On a good day,a standard T100R would reach 110 mph (approx. 8400 rpm).
7000 rpm would be about 91.7 mph.

On a 650 or 750 twin,7000 rpm would be a sensible redline.You're living on borrowed time above that,and parts are beginning to break.Once the fatigue cracks have started,it can still take a long time before a crank finally breaks.If cracks are detectable after 1 hour,you might still get 10 hours use at the same loading.

The T100R would still be happy at 8000 rpm.

Old Cafe Racer

This a T100S not a T100R so theoretically 7000rpm will give you 92 mph which is probably what you can realistically expect to pull in top gear.
A T100S is rated at 34hp @7000rpm so why would you want to go beyond that as the power is dropping off after that point.
The T100R on the other hand is rated at 41hp @ 7200rpm.
Personally I'd be very happy with a 7000 rev limit on my Daytona and only wish I could program it into the Tri-spark.

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tjwood

Thanks to everyone who replied. What a great set of information! I think I'll run with it on the 'Enfield' Boyer to start with and see how it goes - if I find myself hitting the rev limiter (which sounds very unlikely from the figures people have mentioned - I won't want to go more than 90mph) I'll invest in a new Boyer Triumph black box. Once I've got my carb issues resolved, I'll post back here with the speeds I achieve.
Once again, thanks guys.

Old Cafe Racer

If you do hit the rev limiter in 4th gear there is always the option to change to Daytona gearing (19 tooth gearbox sprocket instead of the 18 tooth one)

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JJC1957

http://gearingcommander.com/
Try this website out. I use this on every sprocket change I have done and it is right on. You need to put all info on your bike in first. Don't use the database it is not correct for tire sizes and gear tooth numbers

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2010 Triumph Thunderbird

Snakeoil

I don't think your concern should be hitting the rev limiter in top gear. It would be hitting it as you go thru the gears. That's where you have the greatest possibility of hitting the rev limit. If you plan to wind out the engine running up thru the gears all the time, then having a limit at 7K is probably not a bad idea.

I'm curious. If you ordered the wrong ignition, why couldn't you have simply returned it for an exchange before you installed it? Was it an ebay or swap meet item? I would think any reputable dealer would let you return an iggy if the packaging is not disturbed. I know most electronics are not returnable. I would have also thought that if the dealer was not willing that Boyer would have been willing to swap it out for you.

regards,
Rob