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Been stripping the bike today to check for restrictions that are making it top out at 110mph and iv came the the conclusion that it is a wiring issue, iv read the resistor derestriction sticky but am still confused as to what i actually have too do!

iv taken a few pictures of all the possible restrictors, just so i can have a second opinion and allthe wiring just to see if you lot can spot anything wrong? cheers!

no exhaust washers



no carb gasket washer plate thing?



not sure if this gap is effecting anything?



now all the wiring! iv taken pictures of everything even though i dont know what half of the things are lol









also can someone tell me what these raised holes are for? breathers im pressuming?


this ones the the rear top of the engine


any help please! thank you.

so far I'm not seeing a SP

CV carbs so not SP flatsides

Yes that is a breather on top of the engine

it connects onto the bit of pipe on the airbox

There is at least one airbox bung missing so that you are drawing unflitered air
I would guess you also have other airbox sealing issues

the engine is flithy................suggesting a serious lack of maintainance

That looks like a UK unrestricted CDI box which would suggest that you do not have a factory restriction problem
however is it correctly matched the correct rotor ? assuming tht it really is a SP motor................something I very much doubt

hmmm, well maybe an sp engine but normal carbs? i was shown the donor bike the sp motor came out of which was engineless when i purchased this one and also shown the blown up normal engine haha so im sure it is

okay so i should link the two holes together?

that doesnt 100% mean lack of maintenance, its a 20 year old bike that hasnt been cleaned very often, nott many people i know clean there engines at all

what is this airbox bung you mention? and i have no idea what a rotor is, like iv mentioned before i dont have a clue what im doing lets say its not an SP motor what advice canyyou give me for a normal motor?

there are two access holes in the top of the airbox that allow for removal of two of the bolts that hold the airbox onto the carbs these holes should be blocked off with small rubber bungs.


This is very simple stuff I'm having to explain


The basic principles are the same no matter if you have a SP or regular L model engine.

The ignition pick up rotor is that device that trips the pick up and informs the CDI of where the crank is...............

Frankly given all that I've seen the man who sold you this bike had big windows cos he seen you coming.

okay ill duct tape over the holes, iv just stripped the whole airbox and alot of the small gasket type things are rotted and the air filter clogged! cleaned it all up and used gasket sealer and taping over the holes lets see if it solves anything!

ahh maybe :/ oh well, nothings fun if you dont get to fiddle with it!

okay its not simple for me because iv never touched a big motorbike before haha, well by the looks of the cdi and little boxes, should i not have one of these m max box resistor thingys?

I dont believe you need a Maxbox thingy

You would appear to have UK spec CDI................however I'm still at a loss as to how to explain the 110mph speed issues that you have

Restricted is defo the obvious answer but you seem to have the right CDI...............so something else must be wrong.


I would recommend a full and very extensive service

okay thank you for your help.

i have cleaned everything up, replaced little bits and bobs that were missing like the breather pipes and cleaned all the filters, ill have a go tonight and see what it does

if its still 110mph then ill take it to my local dynojet and get it serviced

one last question, next to the breather hole on the engine casing, there is a small hole with a M6 thread next to the breather hole, should this be covered and what is it for?

The earth lead from the battery is normally bolted on there

if you want a dirty engine take a look at my (now ex) 'manky' bike lol. has somone played about with the carb internals? changed the jets ect? thats about the only thing i can think of really, apart from whats already been said.

It wouldn't exactly take a lot of time to take the rocker cover off so that you can see the cams in your supposedly SP engine with the CV carbs. If they don't have timing adjustment facilities you've been ripped off, you've got a stock motor. Anyone who knew what they were doing (which you admit you don't) would have wanted to see the engine with the rocker cover off before parting with cash.

i was not ripped off at all like i payed £1200 for the bike which is in mint condition and it turns out the older sp motor was replaced with a standard engine and carbs, doesnt bother me lol just thought it was an sp thats all

Did you get it sorted out?

syihabuddin wrote:Did you get it sorted out?

nope :/ still tops out at 110mph

iv read the stickies but they dont make it clear for what bike is which method...

all i can gather from the stickies is that for L models you just whack a CDI on and it should be derestricted?

but i did a gps with my speedo cable in and it showed 108mph and brickwalled and then i tried with my speedo cable off and it showed 114mph but i ran out of "private" road but it still felt like it was pulling, so i dont have a clue what im doing now

carbs, its always carbs...

banner001 wrote:carbs, its always carbs...

They have been cleaned and balanced mate :/ I think it's an electrical restriction from my speedo