So when I stripped the forks I had compressed the preload tube and spring by putting a ball-end allen T-bar in the hole (only on one side) of the preload tube 3 photos above... It was fairly clear that re-assembling wouldn't work with this method...too much force required and just a sense of danger that the spring would release without warning! In one of the Brad the bike boy's videos he says you just have to have the right tool, a fork spring compressor 88713.095 and a spacer, to safely compress the tube and spring. I wasn't even looking, but tinkering in the workshop and spotted a used VW exhaust clamp sitting on top of the pile in the random nut&bolt box... it kinda leapt out that it wanted to be used.. A quick 30 mins with the Mig and a grinder and we have 88713.095* and spacer. (Note the asterisk)
I was investigating fork oils recently to try find volume, viscosity and air gap which also "apparently" compresses also acting as a spring, (I'm adding "apparently" as I'm only repeating what I learned 5 days ago!). My 900ss forks are firm, but work well for how I ride, however the consensus of opinion is that the fork oil in these Showas is too thick creating a harsh ride, and you should lower the W weighting number. Standard Carby 900SS: SHOWA GD011 SHOWA S.S8 or AGIP Fl - ATF. DEXRON SS-8: 36.8cSt @ 40C 439 ml Standard oil level/air gap: 108 mm Standard Inj 900SSie: SHOWA GD131 SHELL Advance Fork 7.5W 22cSt @ 40C 531 ml Standard oil level/air gap: 108 mm However 7.5W and 5W doesn't mean much as there is no standard applied across manufacturers. 5W from one manuf can be the same as 20W from another...crazy. So again "apparently" it is best to use cSt @ 40C as the common way to measure viscosity...(what a geek! ) Anyway found that Motul Fork Oil Expert Light 5W is 17.9cSt @ 40C... a slightly lower viscosity than the standard 22cSt @ 40C...and I could get it locally.
The fork spring holding tool made me smile because I have something that looks very similar hanging up in the garage that I made to do forks years ago.
Not so sure if this will be interest or assistance...maybe we should start a "What fork oil do you use?" thread ... But I found a couple of tables that show proper cSt@40C fork oil specifications...
A couple of good techniques for re-assembling forks... put plastic tape with grease on top over the bush grooves of the stanchions to avoid damaging the seals as you force them over the top. And then as Brad says you need the right tool for the job...a fork seal driver to "bash" home the seal into the fork tube allowing the clip to fit into the groove at the bottom of the fork tube...ahhhh...no you don't! If you wrap enough electrical tape around the stanchion (stopping just right for the outside diameter of the seal) you can use that as a driver... bottom of the forks on the floor and a good number of healthy descents of the fork tubes and the seal is driven home.
With the forks almost fully reassembled...I added the required 531 ml of oil. I made "dipstick" out of a metal coat hanger, however as the oil is thin and clear it is impossible to read the level... so a fine hacksaw blade was used, the teeth trap the oil so you can easily read the level. It was "set" at supposedly correct 108mm..it wasn't close to touching the oil. I would estimate this volume gives you around a 114mm air gap...anyway added more until we got to 108...it's going to be a case of set it up, ride it and see where we are. Finally fitted the fork tops.
So as mentioned elsewhere I finally set up the Gateros Zinc Electroplating kit..I actually had this standing unused for at least 2 years waiting for the project to advance! There's some very good videos on Youtube detailing the best way to use the kit. (The guy restoring an Alfa) I'll admit the kit seemed daunting, I read all the text provided at least 5 times to try to grasp process and setup. Watching the Videos definitely helps as some of the texts provided by Gateros are not particularly well worded.
The kit comes with 4x 10L buckets for the various solutions: Alkaline cleaner, Electrolyte, Passivate blue/clear and Passivate yellow/gold. I decided, mainly due to space constraints to change the 10L buckets for smaller ones, I figured we are at the size of nuts and bolts really, maybe a few brackets max. So dug out some old 2.5L paint tubes...perfect as you know for sure they are airtight (compared to purchased plastic food containers). I actually also bought 2 tubs of the cheapest paint in the DIY store and then threw the contents away...to have the containers. I also added 2 more solutions to the ones in the kit: HCl acid cleaner (Hydrochloric Acid currently at 23% - I may dilute this down). The HCl works really well to strip everything back to bare metal, but you have to be careful with high tensile bolts as the acid can change the physical properties. And the other being a Demineralised Water rinsing bath to limit cross contamination. Also purchased a 30v 10A Laboratory Power supply, the less precise non-Pro ones are really quite cheap on Amazon. The Gateros kit does come with a small regulating coiled wire that is supposed to adjust the current (the part that is important in electroplating is current - movement of electrons depositing the Zinc.. voltage isn't that important). However there is clearly no precision at all using the coiled wire with a car battery as suggested in the documentation. The guide is 0.1A at 0.2-5V for each square inch of piece to be plated, so the power supply allows you to plug in an exact figure required.
I did make up and print a handy excel guide of the Zinc Electroplating process, pinned to the wall above the kit...as you can't really stop to look at the computer with all the personal protection gear on. A tentative first test for bright zinc (blue passivate) was done. These cylinder head washers were first left in Bilt Hamber Deox-C overnight.. ages and ages ago. While the rust was removed, they still looked blackened, discoloured and generally rough. When I thought I'll test the Gateros kit on these pieces, I decided best to run them through Bob's Greatest Invention™ first. Defo the way to go, all the Gateros advice is cleanliness first! (Second actually, after safety) Moving forwards, I'm probably going to go direct with HCl or the Alkaline cleaner as I think it will be more effective than Deox-C...we'll see. The pieces came out great, maybe beginner's luck?
So these cylinder head washers were the last piece I needed to finish main engine assembly... But I still had to fit the valve shims, in the "correct" size... I didn't purchase the small stepped cylinder that makes shim sizing really easy, as I figured you could just work it out using the power of MATHS! - Utter bollox! The right diameter shims finally arrived from Lacey... and all of them were slightly oversize in their thickness. At least it is the right side to have the error...I could carefully sand them down, measuring with a micrometre as we go.. They didn't require much, but f*ck me...figure of eights to ensure even sanding...it took what seemed like days. It was definitely hours upon hours, my arm fell off and re-grew at least three times. (Note: for next time buy the correct tool to measure..., hold on...but that's against my philosophy!)
So...A big day arrived! This is really good solution in place of a piston ring compressor... a plastic PVC drainpipe cut down with a large ziptie (that you then release with a very small screwdriver)...the fact that it is flexible means it's super easy to remove once the pistons are in the cylinder. Quadruple checked for the oil passage orings! And offered up the head... Oh I forgot to mention that I had polished and removed all casting witness marks from both intake and exhaust ports when rebuilding the head...don't know if it will help.. apparently fooling around with ports is a "dark art" (Ooo, I'll admit I'd like to learn more! )
Fourteen mill' spanner on the end of the torque wrench...means you adjust the torque value at the wrench end to account for the longer length...needed 40Nm at nut so set wrench to 28Nm.
And so we are kinda up-to-date... It's not really time for a grand unveiling as engine not 100%...needs belts etc... But so chuffed with how far we have come...so... From here: To here: To here: And all in one short weekend... cough, cough... Edit: I do so hope the b*stard runs at the end..
Tell me about it... and even then it's doubtful it would be ground to an even thickness. As you say just buy the correct tool from Lacey... Love the piston ring clamp. Btw what are the three brass coloured inserts in the barrel for?
They are factory installed, I guess to block off the machining access for oil galleys(?) You only notice them now as usually hidden with dirt behind the belts.
If anyone is torquing up heads with this setup, it’s worth noting that if you set the extension at 90’ to the torque wrench the applied torque is the same whatever the length of extension. It only applies if it’s at right angles and the torque wrench is pulled squarely, a couple of dummy pulls on a non critical item (rear wheel axle) and you’ll have the knack Great write up by the way,
