Engine Rebuild Commences!
Engine Rebuild Commences!
The shabby state of the bike left me in no doubt that the engine probably wasn't in the best of condition, although it sounded ok, I didn't want to take any chances.
Apart from that one area of damage, all else looked pretty clean an unworn. These pistons were already 0.5mm oversize.
And sure enough, it needed a rebore as one piston and bore were damaged, looks like it may have seized at some point. The clutch had been off at in the past, and the center nut never re-tightened properly, meaning the splines were knackered from the clutch basket rattling round, also, the final drive sprocket had excessively worn the splines on the output shaft, and I decided to replace them both, one new off Ebay for a £20, the other from Robinson's Suzuki, who I managed to negotiate over £30.00 off the list price, as they had it sat on the shelf gathering dust, and not much likelihood of it selling.
My first look inside the gearbox. No nasty surprises, a testament to the durability of Suzuki's transmissions. The gears and selector forks were fine, I had decided to re-condition the crank and replace all of the bearings, these I got from a local bearing specialist. There is no need to get genuine parts, and bearing specialists are often cheaper than pattern parts suppliers, A useful tip,
though is to specify German/British/Japanese bearings as I believe the cheaper Chinese ones to be largely crap!
Just as a point of interest, I managed to get a set of Genuine 1mm Oversize pistons off Ebay, along with one set of rings, the other set coming from Robinson's. 1mm is the Max oversize using genuine pistons, however 1.5mm and 2.0mm are available through pattern parts suppliers. 1mm oversize gives 256cc, the full 2mm oversize gives 266cc, maybe a worthwhile over bore, but not good if you ever need to rebore again!!
The grey coating is Teflon, something it seems Suzuki had a fetish for in the 80,s. This stuff was found on the Pistons, carb slides, and fork stanchion bearings!
I decided to paint the engine myself, a decent compressor coming my way, meaning I could build my own blast cabinet to clean bits prior to painting.....I had a new power valve cover I took to my local paint supplier, they matched the color and the semi gloss finish brilliantly.
New shafts, new bearings, reconditioned crank, which was done by P.J.Engineering in Wolverhampton, not cheap but totally effortless dealing with them. Highly recommended.
Never having rebuilt an engine before, but with Suzuki manual in hand, I trial assembled everything, checked it over, then got busy with the sealant!! Although the process was straight forward, it took an evening to rebuild the bottom end, with the confidence that all was ok.
Really felt like I was getting somewhere now, worried about breaking rings or dropping Gudgeon Pin retaining clips into the crankcase bothered me....Time for a brew.....until I saw the reed blocks sat on the shelf.....Barrels off and fit the reeds, barrels back on.....it was good practice, anyway!
The Vapour blasted carbs...the cause of much swearing during the rebuild later......
Clutch installed (all nuts torqued up this time...), water pump fitted with new seals, and cover refitted.....looking nice I think? The carbs were a bastard to fit...and had to come off a couple of times to cure sticking floats. They were vapour blasted, and have new overflow and drain hoses fitted. New power valve cables fitted, along with a replacement power valve servo....the original had a broken gear inside it! The radiator was painted satin black, and the exhausts repainted in heat proof black paint. I'm on the look out for a tidier ignition coil, other than that it looks good.
A look under the engine, towards the rear shock linkage. The bolts have a Green Chromate finish as per the originals, they are not quite so bright in the metal, so to speak!
This is some of the dodgy wiring that made me decide to replace the loom with a good used one. Something that would lead me to some head scratching later.
After reassembly, I oiled and fueled it, running on pre-mix, and fired it up....it ran for all of a second on the third kick then.....died. No Spark! Upon initial disassembly,the loom was a nightmare, so I had fitted a good used loom when rebuilding...was this significant, as the generator and CDI wiring were most suspect on the old loom? (see pic above, of old loom damage) I sent off the generator and pick up, along with the CDI unit to West Country Windings, they checked out the windings having made some small repairs to it (at a reasonable cost) but otherwise pronounced it fit, and sent that back to me telling me they had sent the CDI to an outside source, saying it'll be about a week....2 weeks later, I buy a used CDI of Ebay and get the Gamma running! Several days later West Country Windings ring me to tell me they are not able to repair that type of CDI! Good job I gave up waiting!! I wondered if there had been some bodge in the old wiring that bypassed a faulty component, that replacing the loom could have had a knock on effect? Probably not, as it has started and run fine with another CDI, but I wonder, none the less!
There is a video of one of its first starts in the Video section. HERE