Hybrid Project - RD250 AC/F2

[toffee]

Been tipping along with various little jobs, got the clutch fitted finally. 250LC Microns are now fitted. I had a set of short springs for this so I made some W clips to make up the shortfall of the springs and coated them in red high temp paint.

[toffee]

recently im feeling like this is a dry build rather than a final build...

This evening I Fitted a new 38T rear sprocket and fitted an old chain to calculate the length of new chain needed, but ran into a few issues previously overlooked or missed.

I really need an 8mm offset front sprocket which will line up with the rear chain on a standard un-shaved carrier and also clear the inner face of the chain tunnel of the swingarm. I was hoping a 4mm offset would work but the chain is too close to the swingarm.

Running the 8mm offset or any offset for that matter creates 2 problems, (a.) the chain will hit or run too close to the exhaust and (b.) the chain and sprocket will be too close or hit the clutch pushrod actuator on the inside of the side case.

Problem (a.) can be over come with a secondary chain roller ?????

Problem (b.) ?????

[85RZwade]

Would a smaller countershaft sprocket help with the clutch actuator clearance?

[toffee]

Would a smaller countershaft sprocket help with the clutch actuator clearance?

not sure i get it wade?

[85RZwade]

Well, I assume your chain is running afoul of the clutch actuator axially more so than radially. If you replace that 17-tooth countershaft sprocket with a 16, would the smaller diameter of the chain possibly allow it to clear the actuator?
If not, and assuming you don't want to cut into that lovely swingarm, you could shift the engine over to the left. The engineering never ends.

[toffee]

Hi wade, actually after properly fitting the actuator and side casing with clutch cable engaged/disengaged there is clearance with the sprocket spaced by 8mm!!!!



im happy enough with that,  the only problem i have now is getting an offset sprocket and getting the clean chain run.

[85RZwade]

  awesome, glad you got it sussed. I'm impressed with your results and anxious to see your finished product. About to tackle the chain run issue myself! 

[toffee]

thanks wade, ive  ordered an 8mm offset sprocket from vvmracing.com
and a cheap sprung chain roller from ebay to alter the under side chain run,
i will have to make a mounting plate to hold the roller but cannot do that
until it arrives

[toffee]

back to the carbs, finally got around to fitting the 5mm reed block spacers, hopefully this will aid the fitting of the carbs.

The carbs are lined up to get rebuilt after another ultrasonic clean. going to start with standard jets and settings.

[toffee]

carbs built with 15mm float heights and 1.5 turns out with the air screw.

fitting the carbs between the rubbers is an absolute - p i t a!

Had to split the airbox to access the rubbers from the inside. I estimate I will have to tinker with cae carbs to change jets etc. so Im not going to be able to deal with the torture of this so im thinking of a different setup!

Y boot and uni pod...

It also means im going to change to a sealed battery and fitting it in a diferent location as the airbox will be removed.

[toffee]

so here is what im planning for tomorrows session.

im gonna modify the airbox by cutting the front panel and re-installing the panel 180° so the airbox to carb rubbers line up.

I estimate a difference in height of 12.5mm.

By rotating the pice cutout there will be no need for infill pieces. I can either plastic weld the panel in or I can use epoxy!

[pidjones]

I suggest ABS plumbing cement if it is made of the same plastic 90% of Japanese bikes use. Use the clear (Oatey is our USA producer) cleaner and the black ABS cement (can be made by soaking chips in acetone/MEK for a week or so). Should be as strong as the original. I dobt epoxy as a long-term adhesive. The ABS actually welds the plastic.

[toffee]

thanks pidjones, I got it sorted today !

it turned out ok, i cut the front panel, rotated it 180° and plastic welded it back into place using off-cuts from an old MTB mudguard and a soldering iron!

i took a gamble and left a bit of space between the bottom of the air box and the bottom of the rubber mount to enable fuel to collect if it has to.

anyway carbs mounted and the welds didnt break!
The 5mm reedblock spacers mean I need to remove the airbox to get the carbs out and especially to get them back on when the time comes.

[toffee]

last night i made up some swingarm bobbins after getting a set of hooks for the stand.
I was using the flat pads but the bike kept slipping off them. made some spacers too to minimise scratching the swinger

[toffee]

new clutch cable holder fab'd up last night