M.H. Posted September 18, 2020 Share Posted September 18, 2020 Let me know if you want one laser cut 2 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 20, 2020 Author Share Posted September 20, 2020 Fucking thing is still rattling/tapping, WTF. Wondering if something is makes the clearances close up when it's running or something. Also felt like it's starting to either nip up or something, actually sounded and felt more like it was running out of gas rather than seizing but will pull the cylinder again and check for any damage just in case and pull the carb + fuel tap filter and have a looksy while I'm at it. Goes fucking well when it wants to though haha. 5 Quote Link to comment Share on other sites More sharing options...
tortron Posted September 20, 2020 Share Posted September 20, 2020 do you think the small end has gone, maybe piston is rocking? 7 1 1 Quote Link to comment Share on other sites More sharing options...
GuyWithAviators Posted September 20, 2020 Share Posted September 20, 2020 Your other cat looks a bit stoned eh 4 3 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 20, 2020 Author Share Posted September 20, 2020 4 minutes ago, tortron said: do you think the small end has gone, maybe piston is rocking? Brand new SGP bearing, but you might be on to something with piston rock, will try find my feeler gauges and see what sort of clearance it's got 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 20, 2020 Author Share Posted September 20, 2020 56 minutes ago, tortron said: do you think the small end has gone, maybe piston is rocking? You nailed it I reckon. Gets a bit tighter further down the bore. Piston has a spot or 2 that look like they were starting to pick up, but more than healthy enough to polish out, so yeah going to polish piston, refit, add a decent filter and upjet a bit then just try to ignore the noise as it's already got the biggest oversize piston fitted. 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 22, 2020 Author Share Posted September 22, 2020 Pretty sure this was grabbing a bit, the bigger marks etc were there already but it wasn't rough when I fitted it Little bit of rubbing with 400, 800 then1000 paper later and it's more than good enough for me Shit pics, work phone is a bit of a potato and they were taken in messenger. Also it looks like the piston was hitting the plug lightly I'll be rather embarrassed if that was the noise ha! Had a set of jets on hand left over from my old parts business, so that's a plus I guess Always amused me how economy options saved costs by having smaller heads on them just to save a little bit of brass! While it was apart I realized that the carb has all the 4 stroke bits in it, needle, slide, atomizer, atomizer bushing etc, works out much easier to just buy a new 2t spec'd carb than all the individual bits, so once I get the credit card balance a little healthier I'll order one, they are pretty much impossible to get a spot on tune from with the 4t bits in. Bit of info for anyone interested 4T atomizer and bushing: 2T spec ones: Swapped the projected tip NGK out for a standard tip Denso IRIDIUM POWER I had kicking about And added a nice new Uni filter, which only looks majorly over size and out of place hahaha 9 Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 22, 2020 Share Posted September 22, 2020 You could fit a rotor spark plug to eliminate that problem? Might not burn hot enough perhaps. 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 22, 2020 Author Share Posted September 22, 2020 3 minutes ago, kyteler said: You could fit a rotor spark plug to eliminate that problem? Might not burn hot enough perhaps. It was just me being a dumbass and assuming I could run a projected plug in the new head like I was in the last engine, got it sorted now. If the piston touches the plug now I've got much bigger problems hahaha 2 Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 22, 2020 Share Posted September 22, 2020 Put a rotor plug in anyway because braps / 2 stroke is equally as cool? 2 Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 22, 2020 Share Posted September 22, 2020 I'll send you one if you want to try one. I buy them by the box from RockAuto so I don't get raped by NZ retailers asking too much. 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 23, 2020 Author Share Posted September 23, 2020 9 hours ago, kyteler said: I'll send you one if you want to try one. I buy them by the box from RockAuto so I don't get raped by NZ retailers asking too much. Oooh that could be interesting to have a play with! What heat range are they? Oh and I forgot to add a pic of one of the most important additions to the bike 8 1 Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 23, 2020 Share Posted September 23, 2020 1 Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 23, 2020 Share Posted September 23, 2020 What length threaded section to tip do you need? Quote Link to comment Share on other sites More sharing options...
Raizer Posted September 23, 2020 Author Share Posted September 23, 2020 3 minutes ago, kyteler said: What length threaded section to tip do you need? 12.7mm, but I reckon a spacer and a copper washer would take up the excess. I normally run a 8 heat range, but I may have just scored another full top end that the hotter 7 would be perfect for... Quote Link to comment Share on other sites More sharing options...
kyteler Posted September 23, 2020 Share Posted September 23, 2020 Yeah, you'd definitely have to spacer it, you could get it sitting perfect if you did that too though. Flick me through your addy and I'll try remember to send one on the weekend. 1 1 Quote Link to comment Share on other sites More sharing options...
Raizer Posted October 4, 2020 Author Share Posted October 4, 2020 Finally gave it a kick with the .7 copper gasket, fired up sounded mint, no tapping just the sweet 2T ring-ding Then after a minute or so when it warmed up it started tapping again, way quieter than before but still very distinctively there Pulled the head and sure enough there is witness marks in the freshly polished squish band Thinking the profile of the squish band isn't quite the same shape as the piston crown, was going to attempt reshaping it a little, but the CBFs struck, so try again but with a .9 alloy gasket! Yeah it's ugly, I know this, but don't care, if it works out I may yet get @00quattro00 to laser one from .9 copper. Read on a lot of old bike forums that you can and should anneal alloy with a torch just like copper Fucking swear the old Triumph Barries are trolling! Started again, made a nicer looking one, coated in copper spray instead of attempting to anneal, done. /Haven't started it yet, so until I do it's 100% fixed in my mind haha 2 Quote Link to comment Share on other sites More sharing options...
kyteler Posted October 4, 2020 Share Posted October 4, 2020 Alloy becomes molten around 700deg C. Just, for future reference. 2 Quote Link to comment Share on other sites More sharing options...
Raizer Posted October 4, 2020 Author Share Posted October 4, 2020 I knew that too, just had a dumber than normal moment ha! Think that could be why there is Barrys arguing over using a torch and just putting the gasket in the oven on high. 2 Quote Link to comment Share on other sites More sharing options...
Raizer Posted October 4, 2020 Author Share Posted October 4, 2020 Same again, quiet for the first maybe minute then: *It died from running out of gas, I'd turned the fuel off. Measured squish with it hot, .8 in 3 different positions so in my mind that rules out piston hitting head. Could be detonation? Grabbed a digital timing light the other day when SCA had 40% off specialty tools, meant to be the go for bikes since you set the timing you want in the light and it should flash with the mark at TDC. So just need to remark TDC on the flywheel and see where it's actually firing with the engine running. Was about 22-24° with the old school light at with the engine at kick start speed, so may well be too advanced Other thought is the small end of the rod is worn, sounds like a rotational noise so maybe. 2 Quote Link to comment Share on other sites More sharing options...
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