ZXR400 L3 Motor Build (Bristol)

[jackdim]

Bought it for £450, got a load of t&t and service history but a non runner due to undiagnosed motor problems so stripped motor and found this:




Luckily the valve didn't drop right in and act as a centre punch for the bore so just a rehone and machining to remove head damage was in order. Also decided whilst I was at it I want to give the top end completely fresh components with new pistons/rings/collets/stem seals etc all around. Here's what's its going to cost in parts:



Done countless 2t's motor builds but this is my first 4t build, looking forward to the piston's arriving from Japan and getting on with it. Once done I doubt it would've worked out much cheaper than buying a running zxr400 l3 but I'm happy to use this bike as opportunity to learn about 4t's. Also I'll be happy in the knowledge that the motor will be good for a long while, ready for my jaunt to isle of wight for august bank holiday .

Just wondered as this L3 is an import will it be restricted just via the speedometer? Or by any other means?

Ta,
Jack

P.S. Any bristolian/surrounding area members?

[CaNsA]

The guys at Cradley will let you chat to the mechanics if you ask nicely.
Also, Chris and the guys at DynoPro (Runcorn) are total guru's when it comes to squeezing every last hoof out of a zxr400.

http://www.dynopro-racing.co.uk/index.html

They post on here using the name Dynopro, you would have never of guessed that in a million years

[extonyg]

some imports have restricted cdi's might want to check what sticker and letter is on your cdi.im sure there is a thread about all the different types on here somewhere.

[jackdim]

My CDI, is it a restricted one?

[cargo]

Yeah thats a restricted one

The speedo tells it when you are doing 110 mph and thats yer lot

Easy to undo I'm sure someone will post the link to the details of how to do it......................it can be done in two or three different ways

[jackdim]

I've read about how to derestrict the speedo but just wondered if I'd also need to swap my CDI for a UK spec one in order to fully derestrict it?

[cargo]

No the CDI only reacts to the message from the speedo so if the CDI doesn't get the message then the bike will rev all the way to the red line regardless of what speed you are doing.

If you really want the extra expense you can just fit a different/UKspec CDI................ but why?.............. theres no gain and more expense

You can also just remove the speedo but you need to keep the little electronics bit plugged in or the CDI will see that the speedo is missing and your rev limnit will be 10K if menory serves me right.


Just open up the speedo and bend the little tab out of the way easy peasy

[jackdim]

No the CDI only reacts to the message from the speedo so if the CDI doesn't get the message then the bike will rev all the way to the red line regardless of what speed you are doing.

If you really want the extra expense you can just fit a different/UKspec CDI................ but why?.............. theres no gain and more expense

You can also just remove the speedo but you need to keep the little electronics bit plugged in or the CDI will see that the speedo is missing and your rev limnit will be 10K if menory serves me right.


Just open up the speedo and bend the little tab out of the way easy peasy

Ah! Excellent news that, will derestrict the speedo later on then. Dead happy with that me

[RedexRobB]

This'll give you a clearer idea of what your doing

http://www.zxrworld.co.uk/zxr400/revlimiter.html

[bengone1]

I thought you could just shunt a 10K resistor in line with the pink wire off the CDI and the speedo limiter was canceled? It seems like a lot of work to pry the speedo apart vs a few minutes with a soldering iron. Am I missing something?

[RedexRobB]

As cargo said theres a number of ways to do it, one isprising the tab out, the other is with the resistor. All upto you wich you wanna do

[bengone1]

Whew! I wasn't confused. I will be going for the resistor. Disassembling the speedo and then crimping it back together seems like a pain.

[jackdim]

As cargo said theres a number of ways to do it, one isprising the tab out, the other is with the resistor. All upto you wich you wanna do

Ah nice one! Resistor it is for me as well then.