1989 rebuild update

[oldman]

Started on the brakes, rebuilt front master cylinder and refinished rear master cylinder and caliper mount, calipers next and genuine throttle cable if that arrives tomorrow

[oldman]

Rebuilt/refinished front master cylinder, genuine throttle cable arrived as well, joy!

[Calum]

Looking good.

[oldman]

Genuine cable operates carb and oil pump perfectly but stem that extends in to oil pump housing still too long to fit securing circlip? Definitely ordered correct year from Fowlers? Pattern part from same supplier I used for the red 88 yet to arrive but that was correct length to for circlip?
Stripped rear caliper and really grotty, paint removed (not hard, flaking off mostly) and cleaned, in ultrasonic cleaner prior to refinishing and reassembly. Pitting on piston but have new one anyway.
ANY comments about cable welcome?

[oldman]

Here's a pic of caliper before work. Nice!

[declan]

@oldman have you tried adjusting the cable in the junction box housing

[oldman]

It's not the cable, it's the outer metal end that protrudes throughout the cable entry of oil pump. There is a recess in the end of this for a circlip to prevent cable being pulled out of the oil pump housing. On my 88 bike the length was perfect, meaning you placed the metal shaft through the housing and the circlip secured cable outer tight to the housing. The Yambits cable just did not work, did not pull oil pump pulley unless outer sheath pulled out of oil pump housing 8 to 10mm, also difficult to take slack out of cable at throttle end. Hopefully pattern part I used previously will be here tomorrow to compare, will post some pics when I go back I'm garage.

[declan]

@oldman I did have this exact problem I had to make an adjuster using a clutch cable adjuster

[oldman]

Here is the caliper straight out of the ultrasonic cleaner ready for finishing, need a spray booth!

[oldman]

Cable adjuster wouldn't work, cable length is fine, length of metal insert to oil pump housing too long,

[Calum]

@oldman There is supposed to be a rubber o ring that goes on that metal insert FYI

[oldman]

Thanks Calum, but the insert is about 8 to 10mm too long, I will post some pictures up as soon as I get a chance, grandad duty calls tomorrow so Thursday likely, should have repro cable by then as well.

[declan]

@oldman no the adjuster was for the metal housing like I said the exact same problem I had the adjuster made it so I can either adjust the metal housing in our out more

[oldman]

Repro cable arrived, see photo, with O ring perfect fit, I know it's not much, do you think original cable is designed for a bit of play in it?
If I put a cable adjuster to correct to correct(?) fit would also pull on oil pump pulley opening oil pump prematurely, as fitted inner cable perfect length and opens oil pump in sync with throttle.

[Calum]

Don't forget, there were two types of oil pumps that came on these engines. Therefore I'd expect to see two different types of cables.

That bottom silver one looks more familiar to me, but I have the later engine. Earlier engines use different pumps.

[declan]

@calum yeah I have the same pump as you

[oldman]

Both the Yamaha cable and Yambits (unuseable) cable same length spigot, oil pump came with bike and same as my 88 so no reason to suspect change there. Perhaps I am looking for a problem that does not exist. Repro received today fits perfect though, Yamaha cable operates throttle and pump in unison so no issues with suitability, only that the circlip indent doesn't locate near to cable entry near oil pump housing as per the repro used previously. Will give it some thought and probably leave original in place, maybe make spacer that fits inside oil pump housing.

[oldman]

Stripped the front brake caliper, in poor condition, dust seal filled with brake fluid and piston fitted back to front, you can see a bit of the piston seal in the dust seal groove. Sure the damage was done when the piston was fitted by whoever. Chucked the lot in the ultrasonic cleaner before I touch it, cleaner need fresh fluid anyway.

[oldman]

This is the caliper after ultrasonic clean.

[oldman]

Calipers painted and rebuilt, fitted loose to bike, waiting for rear master cylinder hose to and front cable clip to arrive. Refitted carb with 240 main jet, again waiting for engine water hoses to arrive so I can fill and try starting engine (), speedo cable fitted and swingarm chain protector/upper roller fitted. Not too much to do now, wheels not back from Central yet and Galfer disc unlikely to arrive until new year.