Ledenon

Well, finally got around to writing up our trip down to Ledenon last weekend. Globally not bad, the RG got well and truly run-in although did manage to loosen up one rotary disk at the end of Sunday, but we managed 12 sessions in total with 8 sessions on the 350 (between Pierre-Luc, Pablo and myself) and 4 on the RG. About 50 litres of fuel, and a couple of litres of oil!

The 350 worked a dream all weekend, Pierre-Luc took her out first thing Satruday morning and bedded in the brakes (new disks and wheels) plus to wear-in the tyres. Pablo had his first go on the track soon after, and really did well, finishing the weekend with a great position on the bike as witnessed by his knee down at the entry to the tripl left at the end of the straight.

Although I think he has some work to hit the apex on that bend he certainly had great style!

I followed PL for a couple of laps with the onboard camera, and edited it down to the following small video :

Even the weather stayed good, the rain was supposed to hit on Sunday around lunch time so we packed up at around 12:00, and then hit the holiday traffic to get home around 16:00.

The aftermath of the RG500 was pretty dismal, and I am formally dumping my screwed up rotary disk hubs, to on only use the rivetted ones from now on!

The bike has been duly stripped down to the cranks again for a wash out, and fortunately the bearings seem OK. Don't know if I am going to sell it after this, as I am getting really pissed off with it! Still the next track outing is for the RG500 club at Ales, in October so we will see.

Still looks nice though!

On a different subject, I tightened the head race bearings on the FZR and she now handles acceptabley well, no longer shakes her head, and we will see about a new rear shock in the winter to bring her back to good handling bike, I really enjoyed batting around on her this weekend, and even Libby enjoyed a brief blast!

More work

As suspected 2 of the cylinder head studs didn't appreciate all this repeated activity and promptly pulled through. So the risky business of putting in a thread insert in the 2 stud holes was on the agenda. The tricky bit of this is to ensure all the drilling and threading is done vertically and not on the bonk, otherwise the head won't go on. Because of this I decided to use a drill chuck in the milling machine and setup the cylinder flat on the bed of the mill. As you can see from the first photo managed to fix the cylinder solidly to the bed and then drill and tap for the thread insert. I remember paying a bit of money for my thread insert kit, but it has payed for itself time over especially considering I would be out of the game right now if I had to rely on services from a shop!

Anyway the game plan is to try it again tomorrow with a small amount of gasket silicon on the head gasket, and then if that doesn't work swap the gasket again.

More news tomorrow.

Rebuild continues

Two steps forward one step back....

The engine was finished, and it fired 3/4 kick yesterday, not running very evenly, and I think I have inversed the rear carbs slides i.e. put the one from Cyl. 3 on 4 and visa versa, as they are way out in terms of synchro.

The worst of it though is that the front head gasket is leaking water...

Stripped the front head off and flipped the gasket to see if the leak moves, and it doesn't.... hmm....

Maybe there is a knick in the surface of cylinder holding it proud, or maybe the cylinder head is warped! Ordered a head gasket from Suzuki just in case, it will arive Thursday. Is it my impression or are the threads starting to pull through on one of the head studs......

In the process, changed over the carb slides, and now marked them up with coloured tie wraps. Green = gauche (left), Red = right, Red/black = right rear, Green/Black = left rear. 

In the process of removing the head I lost one of the heads nut washers - looked everywhere, moved the bikes, everything off the floor, removed the radiator, the exhausts to get a better look in between the cylinders, but nothing - really getting pissed off with this. I would prefer to be sleeping!

The head looks OK on a pane of glass, and with a set square, so I think that should be alright, there is a small (very) knick in the cylinder surface which I will remove when I get my new gasket on Thursday.

While I was doing nothing in the garage (!), took the rotary disk covers off on the RHS to check to see if the disk hubs were still tight (they were), so looking good there.

This morning, Libby came for a look, and found the washer in less than 5 minutes - was on a frame rail under the engine - F*&k !

Engine rebuild Update

Had an interesting discussion with a guy from Pro-bolt about torquing his bolts down, and they say they don't recommend anything over 16NM for these bolts, so needing 24NM was too much for it. For the moment I have replaced
with the originals - at least I know they will torque down, even if they disturb the airflow a little.

Finished the rest of the engine over the weekend, When I wanted to install the pistons, the machining on the inside was not quite at the right angle for the gudgeon pins to go through, on 3 out of 4 pistons....So I had the choice to try and correct it myself or send the pistons back to Laurent losing 4-6 days in the roundtrip in the post. After a chat with Laurent, I decided I would try and file them, although after a quick try it was impossible to do manually, so I decided to try and do one in the mill. The difficulty with milling is always getting the workpiece held firmly, and with a piston being round this was difficult, not wanting to mark the exterior of the piston, yet hold it firmly enough so it doesn't move.

Anyway, using very light cuts, I was successful at taking some metal off the inside, and eventually getting a free fit on the con-rod. I did the other 2 in the same way, although I made a bodge of Nr. 2 as I cut too deeply and then had to move the cutting tool out so there is a ridge on that one - I hope it won't matter!

The RG is special in that it uses thrust washers to space out the con-rod on the cranshaft in order that it doesn't touch the crank webs, however the washers are in the small end, so the alignment cylinder, piston, conrod, crankshaft is all linked. So me taking adhoc material off the pistons could affect everything - we will see!

Due to Laurent taking material off the head to cut out the impact damage, I had to check the squish values of the front cylinder, The volume of each combustion chamber is 14.2ccs (measured by Laurent), anyway he gave me the tip of assembling the cylinders with the piston rings removed to that it would be quick to get them on and off, which is what I did.

As you will remember, the technique is to position 3-4cms of 2mm diameter solder around the pistons "stuck" on with grease, then you have to assemble the heads (I just tightened them not torqued), then you turn the engine over slowly and the solder is crushed by the contact with the cylinder heads.

You then measure the pieces of solder and that gives you the squish value of each cylinder.

You can take the average values by adding the opposing numbers and then dividing by 2. The front squish was just over 1mm and the rear was about 0.9mm, In order to change the squish you need to vary the thickness of the base gaskets, which I will need to purchase, as I don't have the correct size. The optimal squish is 0.8 mms for a 125cc cylinder, so the rear is correct but the front could do with lowering slightly. Having a greater squish will lower optimal performance, but is safer for eventual piston, head contact.... so I am on the safe side.

I have now installed the piston rings and cylinders, heads all torqued up nicely, and now I have to attack my rotary disks!

Another quick update

The Ducati is now working, turned out that just changing the stator, although slightly changing the problem (i.e. the reg/rec got hot with the new stator), didn't fix the charging issue, I had to buy a reg/rec as well (RR51 Electrexworld) from a French company at the cost of 120 Euros all in. This fixed the problem, I now have a healthy 14.5 volts on the battery with the engine running. I've had it out a couple of times now, and all is well - I even have a generator light on (normal).

I went out with Olly, him on the FZR 600 and me on the Duke, the FZR has stopped leaking oil from the valve cover, so I think I was probably seeing oil dripping from earlier attempts and leaks, so all is well, except Olly said the head still shakes when you let the bars go. I need to check the tightness of the new headset.

I received my engine parts back from ALCO, with the front cylinders rebored to 57.5mms. Larent left a couple of marks lower down the bore otherwise we would've had to change the cylinder sleeves. So last bore on the front. I also got 2 new pistons for the rear cylinders now at 57.0 mms, he also changed all 4 con-rods and outside bearings on both crankshafts - just over a grand (Euros) if you are interested!

I installed the cranks, and put the crankcase half on, but during tightening/torquing I rounded the head on one of the domed allen head bolts that I purchased specifically for the job from Pro-bolt - not happy! Tried everything to remove the bolt to replace it, but in the end had to drill the head off, and remove the crankcase to remove the rest of the bolt... arghhh. Really pissed off with my (expensive bolts) although the guy at probolts says they are only rated at 16nm torque and I was tightening to 23nms, he told me this was written on the packet - which I haven't checked yet. Anyway replaced with the original bolts which although stick into the airflow, at least they are reliable.

Just in the process of putting my pistons in!

More news as soon as it's together - supposed to be going to Ledenon in 2 weeks time, to run it in!

Speak soon.

Quickie

Put in bigger pilot jets in the RG500 carbs: reference : 30 jets