canamant

Outside of swingarm measurement is 320mm so spindle bearing surface length needs to be that length. Bit longer would accommodate washers/adjuster markers. Diameter 20mm. Thanks.

Let you know later Swirl. Ta.

Anyone know if a bandit 6 or 12 rear wheel spindle is the same length as a slabby 11 ? Thanks

This dropped through the letterbox today. The team at Hagon spent quite a while talking to me on 2 occasions about custom building this for my weight, making it longer to compensate for the 17 inch wheels and road race application, and most importantly ensuring it doesn't foul the frame or rocker as happened when I fitted the R1 shock to Slabby Racer 1. 10 days order to delivery including the Easter holiday.

I omotted to say "someone who knows about turbocharging will be along shortly" :-)

I'd recheck with the dynamometer operator. Dynamometers measure torque and then convert it to bhp. It does this by recording torque, engine rpm, and dyno rpm and then doing some sums. It "knows" what the overall gearing between the crank and the drum is because it gets a tacho signal from the engine ignition system and a signal from its own roller/drum. If the roller is limited to 150mph then the operator only has to ensure he uses a gear which will not exceed the drum maximum. In the past I've had runs in several gears with always the same torque/[power within experimental error. I would expect your dynamometer operator to know the limitations of his instrument. Perhaps he just wants to know what gear to run it in, but he should be experienced in these things.

If I remember correctly that low compression would be better for a turbocharged engine.

The slabby ones are sealed units so no adjustment. Even if you did get it apart, and the components were get-attable I would not bother trying to tweak a 30 year old electrical component. Just keep an eye on the tach and make sure the gear link is positive with no slop. If you really want an adjustable unit - the ignitech is supposed to be a good reliable unit but I haven't tried one myself.

Compression will be a lot lower as the 1127 pistons have a 1mm or so flat topped raise on them compared to the bandit piston which has a true flat top. I've just this week measured the CR of a bandit 12 cylinder and piston on a 1127 bottom end and head. I came out at about 8.5 to 1. Head volume was 33cc, squish vol 6.1cc, swept volume 289cc gives a CR of 8.4:1 which is poor. You would need to check valve to piston clearances to see how much you could skim off the head then recalculate. Might be easie r just to stick to 1127 ?

Doesn't make much difference really. Look at most engines and full advance is similar irrespective of cylinder size. As for rev limits, weigh the pistons/rings/pins and compare with standard. then do the load calcs to see what revs will give the same load as the standard piston. My 860s use standard ignition systems but I limit the revs to 10k with the odd squirt to 10.5 if absolutely essential. No biggie really as peak power is at 10k. The piston assembly is slightly heavier than the 750.

My experience of running bellmouths with no filters is limited to race bikes. However I've never seen any significannt piston/bore /ring/valve/seat wear. Admitedly the mileages aren't sky high (thousands rather than tens of thousnds of miles) but race bikes operate right on the edge in a very dirty environment very very close to other bikes with high wind speeds and race tracks are surprisingly dirty places too. I'd happily run open or very large mesh strainers on a road bike without worrying about engine damage.

Thanks boys. My 3 slabby tanks are all the "small" ones. 2 have 34mm taps and the other is 44mm as is my Slingy 1100L. Looks like I'll have to bite the bullet and buy a GSX6 tap for the slingy. I had it running after a fashion this afternoon but the fuel supply was dodgy. Looks like eblag will be my friend.

I need a fuel tap for my 1100L racebike tank. 44mm centres. GSX600 taps are 44mm but are twice the price of bandit ones from that site. Does anyone know what the spacing is on bandit taps ? Thanks Ant

The powerscreen ones are 4 inch (100mm) longer.

Brief update (because not had much time lately to get much done) Finally got hold of a cutting tool to cut back the tops of the valve guides to give more collet to guide clearance. I removed between 0.055 and 0.060 inch (1.4 to 1.5mm) to leave all the guides the same distance from the head face. This was a touch more than necessaey but was done to allow a higher lift cam in future. I removed sufficient metal to allow the valve springs to go just shy of coilbound when the collets touch the guide on levering down with a pry bar. No point in removing any more metal. A quick clean off of the guide bore with a countersink/pilot bit and all good to go. Apart from on rocker. See picture. Anyone got one out of a scrap engine as I don't really want to put it back.

was hoping Spike would start doing them.

Mole28 Where did you get the fairing from. I'm struggling to get one for my 1100L race bike (not the slabby in the winged hammers section). Had one from Ricambi Weiss but wouldn't go near so posted it back.

Wow. Looks like someone DID just bolt them in and hope for the best. Sprockets aren't even slotted to get timing right. Dot heads must be subtly different to get the clearance

I'm trying to sort out the cams and cylinderhead on my powerscreen motor which will be going into my Slabby 1100 racebike. Not being one to just bolt stuff together, I've produced 2 camgraphs and measured piston to valve clearances from 20 deg BTDC to TDC for exhaust and TDC to 20 deg ATDC for inlet in 5 degree steps. Clearances are fine here. The cams are massively different, inlet being quite racey in profile and timing and exhaust being very conservative. Both cams have a "B" stamped into them on the end. Any ideas what this is ? Also, on full lift. there is only 0.014 inch (0.36mm) clearance betweeen the valve collets and the inlet valve oil seal/valve guide. You woul dusually expect a minimum of 0.050 inch (1.25mm) to allow for valve float on a race engine. Even though these are road engines, you would expect more than 14 thou clearance. Has anyone out there got specs on this clearance in this engine or measured this clearanc ?. I'm just wondering if a previous owner has swapped a cam and not checked clearances. Slabby 750 cams will give about 0.080inch (2mm) clearance on my other race engines. My reground cams won't even turn over as the cam lift in this power screen head is greater than the valve collet to valve guide distance. Thanks

I slotted the backplate on both my 750s /860s and noticed it running about the paddock and in races. The pick up at tickover was noticeably better. Why does this make a difference on a race bike you ask. Well I don't rev the brains out of the things when the red light comes on so the instant pick up means I'm not bogged down when the red light goes out.

He had sold the last of the batch when we last spoke. Think I've got enough clearance to get away with a longer shock absorber. Had a mock up tonight with an old slabby 750 unit attached to the swingarm with a space piece between the top eye and the top shock mount. No catching on the swingarm or frame. Thanks to Creg Ny Baa for the advice.

Not done much really over the last week or so. Engine is giving me some headaches with the pistons and cylinders kindly donated by Dave Whitehead via YoshiJohnny. Very low compression of 8.8:1 which I can get up to about 9.5:1 by skimming the cylinders to flush and skimming the head to the minimum valve to piston clearance. Might just have to live with it. I toyed with the idea of a DOT head but would run into carb/frame issues so staying with 1127 head. Progress on chassis sort of coming along. I've made up a couple of rods to mimic the rear damper. 315mm looked like a chopper with 1100 slab forks. Made one up at 325mm ias shown in the picture. Still looking like a chopper. The rear end will be tipped up by about an inch with the front and rear tyres on but it still looks like it will turn like a barge. Anyone know how long I can go on the shock before I run into clearance issues or the swingarm angle becomes too much ?

no - they don't fit. at least they don't on mine. The colanders are taller on the 1100.

short stroke 750s (748) have a 73mm bore while 1052 has 76mm bore and 1127 has 78mm bore

Couple of nights in the shop trying to prise apart fossilized parts. What I found inside was a welcome change. No corrosion, just a bit of sludge and guk. The water hadn't got above the sump plate. I'll be putting it together with new crankcase seals but re-using the shells as there is precious little wear on them. On hold at the moment because I need to get a timing chain.