KLX engines

[cloggy]

I just picked up two KLX's that I'd ebayed
One is an unfinished UK 1981 bike missing various plastics and with the wrong shocks. The engine has been rebuilt by a Williams Formula 1 technician, supposedly.
The other was complete and running 1979 import [plastic tank, longer seat] rebuilt by a 14 year old. It sounds great, but I wonder how tight some of the bolts are.
The later bike is supposed to run 6v electrics but the wiring needs doing. The earlier bike is supposed to run 12v lights but mine is lightless. Can I swap engines and just deal with the different electrics by swapping the sidecovers? I've got a 1979 manual winging it's way to me but with the weather...... I ended up changing van wheels in the snow last night, tyre blew out.
Secondly I've seen the correct shock length quoted as both 440 and 460mm. Did the roadgoing later bike run a slightly shorter shock?

[TT5 Matt]

ive got a 82 model and that runs 460mm shocks,hagon shocks quote 460 and 440 so maybe the 440 was for the countries with short people that have trouble touching the ground 

[LWC82PE]

The article in VMX mag says the only difference was the regulator between the 6 volt and 12 volt. I dont know how true that is though.

[cloggy]

Thanks both of you
I had to strip them down to get both in the van and upon reassembly have noticed that the carbs are different. The 14 year old's efforts resulted in the throttle jamming open. Luckily the engine survived but a closer look showed the  throttle linkage to be on the opposite side, and a missing airbox.

[gtmpaul]

Hi,
The earlier A1 & A2 all should run 6v systems, the later B1 had a more complete loom and was 12v, if you need any info, I have all the parts lists and manuals.
The shocks were all the same
Cheers
Paul

A1-A2


B1

[cloggy]

This explains why my early running bike is virtually wire less whilst my later one is festooned
Is there any reason why I can't run the earlier wiring system with the later motor?
I note what appears to be the later magneto has only 4 output wires to the earlier one's 5; so I guess what I still need to know is if the magneto [or at least the lighting coils] is attached to the outer cover and if so are the flywheels identical?
I don't mind swapping electrical componants over on the actual frame. Any chance  Paul, that you could send me the later wiring diagram in a form I could increase the scale?

The later diagram appears to show two wires to the CDI box, one to a battery via a rectifier, and one direct to the headlamp which appears to be running AC. This is pretty much as the Suzuki DR400 where the ignition and lighting are also separate.
That being so I suppose I could simplify the wiring and just run one  or both lighting wires straight through the system  with a heat sink taking off excess voltage.
Paul, do you have specs for the correct spring rates? [and thanks very much for the info so far, I was hoping you'd see the post]
The early tests all said both ends were too soft so I'd rather know what works on the rear shocks rather than the original specs. I've got the original shocks on one bike but they look to be leaking. Is there any particular make of shock that will fit behind the sidecovers?

[TT5 Matt]

on the 2nd wiring diagram the pickup/pulser coil is shown at the bottom of the cdi box with 2 orange wires connected to it and that is located on the outside of the cdi charge coil and lighting coils and needs 40 to 50 thou air gap,the cdi charge coil wires are black and black/yellow in colour,the green goes to the half wave recterifier and the yellow does the headlight and speedo globes,falcon shocks over your way had a good list of shocks with spring rates or contact wasp on this site for yss shocks

[cloggy]

Thanks very much for that. I've spoken to Robin at Falcon and he can do an off the peg Red Rocket type shock with around 5.5" of travel, which is as close as I'm going to get to the original 5.9" without serious extra money. I don't think they are going to fit behind KLX side panels though.

[grouty]

Thats quite interesting !  I have a B1 that has 6 volt electrics. I will measure the original shocks tomorrow out of interest as well.
I spoke to Robin about a year or so ago reference new shocks. He reckoned about £450 for a pair. He could not do them with the remote resevoir though.

Cloggy .... airboxes are like hen's teeth. Good luck.

Paul .... are you going to Telford next month for the classic offroad show ??  Be good to meet up.

[cloggy]

One of the bikes has a complete airbox.
The VMX article seems to imply that one of the interim models has  12v. I've no idea what mine has

[YUMASTEPSIDE]

.......just a question,whats the difference between the KL250 trailbike motor and the KLX250 motor ??

                Roger

[JC]

Not a lot. KLX had 1mm larger dia valves.

[Nathan S]

KL carby was larger, but is the more restrictive CV type.

Edit: Maybe.

[gtmpaul]

Hi Cloggy
Do you still want a better copy of the wiring diagram?
also do you need an air box? I do have a lot of spares, just no shocks, cams or heads.

Ian, I will PM you about Telford, I just need to sort out a Pass with the wife


Cheers
Paul

[cloggy]

UK  KL had a smaller slide carb.
I don't want to spend loads completing both bikes Paul. On the other hand an airbox and carb would enhance the spare bike's value.
I am missing one side panel, one rear mudguard  Both  headllamp assemblies, one carb, one airbox, one tail light.
I have one spare swing arm and rear wheel spindle and one spare engine in bits with seemingly a good head
Both rolling chassis seem good apart from the swing  arm bearings on one.
The running bike has a modern Keihin which needs the choke optimising, so I'm switching carbs tomorrow. And yes I would like a better copy. of the wiring diagram please. I can show it to experts at the twinshock show and then simplify it with modern components.