tommcb6016 Posted June 16, 2012 Share Posted June 16, 2012 Ive been doing some maintenance today on my carb and when I put it all back together I was turning the engine over by hand, I noticed a grinding coming from the rear of the engine in the location of the coil Is the coil fixed to the back of the engine ? I'm guessing it shouldn't move about as the flywheel rotates around it? Guess I'm having my engine off tomorrow! Better not be bloody flyable or I may cry!!! Tom Quote Link to comment Share on other sites More sharing options...
pete_b Posted June 16, 2012 Share Posted June 16, 2012 Coils should not move. flying in this weather!. Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 16, 2012 Author Share Posted June 16, 2012 I think one of the studs has gone or bolt come off either way it's probly a replacement coil I should think. What wrOng with the weather? It is June'uary' after all Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 17, 2012 Author Share Posted June 17, 2012 Well I've just taken the engine off and removed the flywheel.. One of the studs was loose and one pole of the stator is mangled! Also two of the magnets in the flywheel are cracked. The electric box is covered in cracks and falling apart so need a new one of them as well Parts bill £100 plus postage, could be worse ... Might use it as an opportunity to get the frame re powder coated as its stripped down. Tom Quote Link to comment Share on other sites More sharing options...
Guest Posted June 17, 2012 Share Posted June 17, 2012 Polish it SW Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 17, 2012 Author Share Posted June 17, 2012 Not sure if I can be arsed to polish it.. thinking matt black powder coat but not sure. Bits on order.. quote for powder coat tomorrow Quote Link to comment Share on other sites More sharing options...
ptwizz Posted June 18, 2012 Share Posted June 18, 2012 If you're thinking of powder coating, take a look at stove enamelling. It's thinner, lighter, tougher and can be touched up if you scuff it. The bake temperature is safe for heat treated aluminium alloys (although I would check with your supplier). I've used both powder coat and stove enamel on wheel rims. Stove enamel will stand up to tyre levers while powder coat didn't. Pete. Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 18, 2012 Author Share Posted June 18, 2012 I need to get the powder coat off first.. Nitromors is doing it but think its going to take me all bloody week We use something called "E coat" so might see if I can get it done through work. But may polish it yet.. at least then you can see any cracks. Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 20, 2012 Author Share Posted June 20, 2012 Bits came next day thumbs up to Parajet for excellent service If I do polish the frame does it need any protection to stop it tarnishing ?? Tom Quote Link to comment Share on other sites More sharing options...
Guest Posted June 20, 2012 Share Posted June 20, 2012 No, not if you polish it to a nice mirror finish. It will just want a wipe over with a bit of t-cut when your bored. SW Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 21, 2012 Author Share Posted June 21, 2012 I went to reassemble the stator/flywheel this morning and discovered the reason for the original failure, the shaft appears to be bent (about 0.4 runout) so the stator was rubbing on the flywheel ! it looks like its had runout for a long time (judging by the groove around the inside of half the flywheel) Not really sure what to do now, do I strip the engine completely and straighten the shaft (not keen!) or do I stick the flywheel in the lathe and skim 0.5 from the magnets? ( not even sure if that's possible as I've never tried turning magnets before ) Help! Quote Link to comment Share on other sites More sharing options...
ptwizz Posted June 21, 2012 Share Posted June 21, 2012 You absolutely need to get the flywheel running true. Machining magnets is not good. If they're not made from the hardest substance in your workshop (I can attest that Lucas Magneto magnets are!) then the interrupted cut will impart a series of shocks which will reduce their magnetism. The magnetic field surrounding a permanent magnet dereases as the cube of the distance from that magnet. If you double the gap, you will have 1/8 of the field strength through the coil. A wobbly flywheel will cause vibration. Even if you correct the static balance, their will be a dynamic imbalance. Vibration will cause further damage to your engine and increase fatigue in the frame and prop. Pete. Bailey 175 Ozone Indy Quote Link to comment Share on other sites More sharing options...
enzo200500 Posted June 21, 2012 Share Posted June 21, 2012 Could have worn the crank bearing on that side as well! Time to open her up.....methinks. Quote Link to comment Share on other sites More sharing options...
Guest Posted June 21, 2012 Share Posted June 21, 2012 I agree, thats a surgery job. SW Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 21, 2012 Author Share Posted June 21, 2012 I had realised that was the likely outcome, but the idea of stripping the crank out fills me with dread.. Not even sure if I'll be able to straighten the crank (if that's the problem) Quote Link to comment Share on other sites More sharing options...
Guest Posted June 21, 2012 Share Posted June 21, 2012 I am 100% sure that a new crank is the way to go if its bent dude. SW Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 21, 2012 Author Share Posted June 21, 2012 Your probably right, but I ain't got the cash for that at the moment so I'll have to do what I can Need a new ring gear too as half the teeth are mangled At least it raining ha ha ha ha Quote Link to comment Share on other sites More sharing options...
enzo200500 Posted June 21, 2012 Share Posted June 21, 2012 I would be very cautious about trying to straighten the crank. If not done absolutely spot-on, it could still cause issues with the main bearing. Speak to someone like Stan Stephens, Mick Abbey, Graham File etc. They deal with 2Ts all day long! Sod the poncey polish job and get the motor sorted first!! Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 22, 2012 Author Share Posted June 22, 2012 Yes worrying about the frame finish is now the least of my worries! Spoke to a friend who said its very unlikely to be bent, but more likely that the two halves have gone out of balance. Got some v blocks and 2 clocks so will get it out tonight and see what's going on, but saying that if I think it looks dodgy I will just replace it.. Need to get the bloody ring gear off first tried pulling it of with no luck, will try with a bit of heat in the minute. Tom Quote Link to comment Share on other sites More sharing options...
enzo200500 Posted June 22, 2012 Share Posted June 22, 2012 How or why the crank came to be out of alignment is a bit of a mystery? If you can get it back to within tolerance, it may be worth just spot welding the main wrist pin to the webs. They can easily be ground off if you ever need to rebuild the bottom end. Only use a copper faced mallet to straighten the webs!! Keep us informed on this one Tom..... Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 22, 2012 Author Share Posted June 22, 2012 Well I managed to strip the engine down tonight got the head off, getting a bit late to be banging around so will leave splitting the crank case for the morning. the head seal and o-ring need replacing, as does the ring gear. Might as well get some gasket paper and replace them all well I'm at it. https://www.facebook.com/photo.php?fbid=10150891589902596&set=a.110287622595.98513.585967595&type=1&theater Tom Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 23, 2012 Author Share Posted June 23, 2012 Well I split the case this morning and started sorting the crank, managed to get it to within 0.05 but will try and get it better this afternoon. Need to replace the bearings as they don't feel fantastic, need to get a bearing extractor first though and find out what bearings they are. All good fun Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 23, 2012 Author Share Posted June 23, 2012 Mangled ring gear... Carbon build up on top of piston.. what's the best way to remove? Quote Link to comment Share on other sites More sharing options...
enzo200500 Posted June 23, 2012 Share Posted June 23, 2012 Use a scraper VERY CAREFULLY, then polish using wet/dry 1200, then Autosol if you want to really get a shine! Carbon has a much harder time sticking to shiny surfaces. Treat the cylinder head the same, shiney=good!! Chuck a set of rings in if the piston has not done too many hours. Quote Link to comment Share on other sites More sharing options...
tommcb6016 Posted June 23, 2012 Author Share Posted June 23, 2012 A bit better.... The rings look ok, is it worth changing anyway ? Quote Link to comment Share on other sites More sharing options...
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