Speed restrictor removal instructions...

[Warwick]

Finally found a copy of the old instruction sheet I put together ages ago:



Hope it's of use.

If you'd rather not doctor the clocks themselves, using a kph/mph in line converter on the speedo cable will achieve much the same effect.

[ash33]

I never would have though that so much of the tab needed to be cut away

[oldbiker]

That`s something I never knew about,

[Warwick]

As noted, it won't really give you any more power, but it will stop the restrict signal going to the CDi when you hit 180kph. It just gives you a few more revs in top really - assuming your motor has the power to pull 'em of course. It's a worthwhile mod if using an oem CDi, but effectively you'll only feel any effect at over 11k in top, so in most cases you'd feel very little real world benefit as in the lower gears it'll rev-out cleanly in any case. And a stock 3XV is about running out of puff by 180...

A bit depends on pipes though, so a stock 3XV with good pipes, but a stock Cdi will feel the benefit more than a stock motor running the stock pipes, which do a good job of capping the power on their own.

I guess what I mean is: don't get too excited...

[eire_3xv]

Ive got that red posh delimiter in mine , im guessing it does the same thing . ive had 200kph on my 1993 r model , standard except for nikkon pipes but at that speed its screeming near the redline so ya wana back off eather way before it goes t1ts up 

[wullie3XV9]

DO NOT REMOVE THE LITTLE TAB THAT SITS BETWEEN THE TAB SENSORS WHEN THE SPEEDO READS ZERO KmH.  ( I'd removed that tab over the winter ! ).
ENGINE WILL NOT REV. PAST AN INDICATED 12,000 RPM ( 11,200 - 11,300 true rpm ), IN ANY GEAR AS A RESULT OF CDI NOT RECEIVING REV. LIMITER DE-ACTIVATION SIGNAL
FROM SPEED SENSOR UNIT INSIDE THE SPEEDOMETER ! !  
I've had to make & fit a replacement tab, which on testing afterwards, now allows the engine to rev. up to an indicated 13,000 RPM IN ALL GEARS ! !    
( -40 stock CDI with +2 degree advance woodruff key currently fitted ).

I found this out during plug chop runs last week & today as a result of fitting my set of MARTIN77 expansion chambers.
( Final gearing for all test runs was my trackday 15 / 39 gearing ).
I thought the stock pipes were causing the problem, but it was of my own doing ! ! Much embarrasssment !        

[Warwick]

DO NOT REMOVE THE TAB THAT SITS BETWEEN THE TAB SENSORS WHEN BIKE IS STATIONARY. 

Do you mean you should only remove the tab whilst you are riding it, Wullie? Sounds a bit perilous to me...   

[wullie3XV9]

DO NOT REMOVE THE TAB THAT SITS BETWEEN THE TAB SENSORS WHEN BIKE IS STATIONARY.  

Do you mean you should only remove the tab whilst you are riding it, Wullie? Sounds a bit perilous to me...  

                                                                               
      
                                                                       Now edited !  
                                                          
                                                            In a good mood, Warwick ?  

[Philwhite]

Dear WarickB I am quite new to this site ,I find it informative,but with regard to your derestrictor instructions I am a bit confused,please can you tell me at what speed the speedo is reading in picture 1 and picture 2,(left to right).I find that the bike is struggling to rev past 10500 whereas before on a flat stretch o n good day it would run to 11500 indicated rpm and beyond.I am not a big fan of coincidence,although we are going in to summer and the temp and humidity can change.Plugs are burning too black.I went down one jet size from 180 to 170. 180 on rear,190 on front is normal for my bike and the motor seems to be stock and pipes standard,although recently had them cleaned out.It is possible that that I have misunderstood your instructions in that case what material did you use to repair the tab and put it back to standard.

[Warwick]

Both at zero. If you have trimmed as per the pics leaving a small tab between the sensor tabs at '0' and have reconnected the wiring etc., then I don't think your problem will be related to this modification (assuming you haven't damaged the circuit board or something? But they seem pretty robust and I've never managed to do that myself). I've never replaced a tab myself, but I'd think that something like a bit of coke can or similar would fit the bill quite well?

[wullie3XV9]

Both at zero. If you have trimmed as per the pics leaving a small tab between the sensor tabs at '0' and have reconnected the wiring etc., then I don't think your problem will be related to this modification (assuming you haven't damaged the circuit board or something? But they seem pretty robust and I've never managed to do that myself). I've never replaced a tab myself, but I'd think that something like a bit of coke can or similar would fit the bill quite well?

When I blundered & stupidly cut off the small tab that sits between the limiters optical sensors at zero Kmh, I made & superglued on a new tab made from a bit of cola can. 
It worked on mine. 

[Philwhite]

Hi Warick,PhilDurban reporting,It seems that you are correct with regards to the restrictor because the bike is running better,problem seems to be a number of things happening at once. I assume that the first picture is before and the second after, the main problem is crap/rust in my tank solved that by fitting fuel filter.No more problem although the rear cylinder is still running rich,will have to work on the float level/jets etc,anyway thanks for the info,Regards PhilDurban.

[Jack Sprat]

Hi Guys,

I bought a ropey 3xv1 2 months ago and it has been giving me sleepless nights. I have cleaned and replaced almost all the parts in the carbs. I have fitted new idle and main jets, new needles and needle jets and new mixture screws. Checked the reed valve stop plates. Fitted new air filters and plugs. Checked pistons/rings and made sure the compression was good. Removed the exhausts and made sure the power valves were working and set correctly.  Set up the carbs and did plug chops for the last two weeks. The old girl would just not run well in 4th, 5th and 6th gear. No power and miss fired over 10000 rpm.

I was reading through the technical forum and read this post last night. I removed the speedo and the whole tab was removed. Today I made a new one trimmed to about 210kph and fitted it, what a difference. It revs and pulls much better. I need to reset the carbs and it should be a winner.



Many Thanks
David
Cape Town
South Africa

[marksoulmotocross]

Hi,Help. Could anyone assist me i have a 3xv r model with raised compression and pipes it has just run in pistons fitted so should be quite perky. It reads about 115 with standard gearing.The thing I'm not sure about is i have a mph speedo from a 600 fitted. With no signal to the cdi will it rev out in the gears and what about the maximum speed signal that will also be missing. Also i fancy trying a advancing woodruff key , what is it that fits the 3xv crank.I know you can buy them for yamaha race quads 450 660 750. Would a posh box be any good for me, and if so were could i get one. I actually have a m max box but it has no connection on the mph speedo so i dont know if it would work. As you can tell i dont know what i am doing. i am about to have the cylinders cut to a higher spec but need to sort all this restriction thing out first. Help Help

[Hendo]

Hi,

I do believe you were the winning bidder of my front brake discs on ebay? They were posted yesterday by the way...

Anyhoo, to the best of my knowledge the bike will not rev out (past an indicated ??12,000RPM??) without the signal from the speedo. I put a MPH clock in my bike, I was lucky in that a member on here sold me a posh firm moto box so I could do it. They dont seem to come up very often but you may get lucky.

Warwick, the forum moderator was very helpfull when I was doing this. Malc of this forum was also trying to replicate the posh moto box, although Im still unsure what the outcome was.

An M-max box is only good if you have the standard speedo, so you can plug it inline. If you have a different speedo fitted, a M-Max box is a waste of time.

Do some searches using the search bar, there is plenty of info on it.

 - Andy