Ok, the bad news is that the work on the clutch side cover got shelved late last year due to my health issues, but I did remove all the powder and make up some Alumibrite at my mate’s workshop to dip this and other stuff in. When dipped the acid (its only about 2%) eats the oxidsation, the reaction is so vicious that you can't see whats happening and to make matters worse you can't leave anything in too long or it turns the alloy black... and you cant get it on yourself of course... nasty, but good, stuff! Anyway, the cover will get re-coated when I get back into the workshop, after another dip in case any oxidisation has come back.
FWIW I also spent a bit more time sanding down the edges of the cover to ensure none of the more serious sanding marks remain that would show through, powder is forgiving but things like that will still show through and this is a part that needs to be nice and flat as marks stand out and ruin the look of the engine, disappointing after so much work to build a motor. I'll do an initial powder and sand that area all back first as well to give it a kind of 'pre-coat', that will ensure that the final coat is nice and flat with no tell tales. Powder is amazing like that, you can powder over scratches and scrapes as a 'filler' if you know what you're doing. Ok, no business would bother to do it for you, but when doing it yourself you can save quite a few parts this way, eg. my F2's dented and scratched grab rail was saved with some welding, grinding and then extensive use of that technique.
So onto something I have actually done... A few weeks ago I did the ‘brass ball clean up’ on the resto LCs 4L0-01 carbs and this week it was the turn of the carbs for this project. The correct carbs for the ‘85 51L motor in Aus are 1GA. In Japan there was a 51L version, but those were the single pull type like the USA carbs on the RZ350, we didn't get those instead we got the 1GA which was the first of the PJ type that and the 1GAs continued with the Aussie 250s thereafter. Ive no idea why they did that, why not just ship us the whole 51L bikes as our RZ250R, hmm... Maybe we had an aversion to those single pull throttle linkages for some reason lol. Ok, its more likely that dealers knew how to service the bikes with the twin pulls and many parts are common, this would have saved training and spares holding costs. Anyway, ours make the same power as the Jap spec bikes, so its no bother, tho really you'd think being a PJ there must be some improvement while running as Yamaha moved to all PJs on the 350s as well in ‘86.
The carbs were pretty horrible that Im using. Obviously been left to stew with fuel and water in them for some time :(
And how on earth do you do this to an air screw? I had to heat the carb body up and spend a while on this to get it out. sigh.
I bought a kit from Cruzin Image on ebay which is for the RZ250R and actually contains needles and jets etc. The needles do look very much like the OEM 4N10s and the nozzles do look like the 345P
n units as well. The pilots were the correct 25s, but the mains were 180, OEM was 155. To be fair n the ebay listing he says that these are 180s. The rest of the kit is very nice, using a rubber gasket instead of the usual cardboard, but including the smaller carb top flat rubber washer as well as the larger one. The inclusion of the smaller one is bizarre, you cant change it on any RZ, only the LCs and then these washers are a special 3 piece bonded design, not straight rubber like the kit. I guess the kit is the same as the one for the LC ;) The brass washer for the nozzle/main jet and the aircsrew were a nice touch as were new screws for the fuel shut off valve. sadly no idle adjuster screw, but no one else even supplies the airscrew so that’s a moot point lol. All in all a good kit for low dollars. Previously Ive used TourMax kits which are fine, but have less stuff and cost a little bit more.
After a full dismantle, balls out and an ultrasonic clean and then the new kit fitted, this is what they look like. I should add that vinegar is amazing stuff, it even eats carb poo and gives brass a good shine. I left the brass in for about 2 days and that worked very well indeed on those parts. I didnt leave the carb bodies in neat vinegar, that would ruin them, only the brass.
Of course I also rezinc'd the screws and the fuel hose T piece and the fuel hose clamps (not in shot of course) and no i didnt zinc the needles LOL!
Earlier I've spoken a bit about the 250 51L engine and why its special, but this pic (from LB’s N1 build) shows the extra port nicely.
Remember no other RZ has this technology, I know that the licence would have been costly from my work on KX and KDX motors back in the day and this makes me wonder why we had it at all. Perhaps one of Yam Aus’ execs rode the ‘84 51L in Japan and said ‘that’s the 250 we need to beat the RGs!’ or something. LOL!