The next valve check is due at 30k but thought I'd tackle it early this year, and at the same time remove the headers to try and get a small pinhole welded in one of the cross pipes and while everything is off clean up some flaking paint on the front of the engine and the radiator. Drained the coolant (was due anyway) and made a start on the stripdown, forgot how much crap you need to remove to get anywhere near the cam cover and how much space is required to store everything safely. Mmm, clean Yuk, not clean Won't have to remove the throttle bodies unlike last time as I replaced the stupid JIS screws holding the throttle cable bracket with Allen heads Going to leave the cam cover on for now until I've cleaned and painted the front of the engine. Don't worry I did bung up the throttle bodies shortly after the pic was taken. Radiator off, in pretty good nick, I repainted some corrosion on the side tanks while on the bike about 5yrs ago, there's a small patch bubbling up again so will clean it up and respray left soaking with snowfoam then blown through to clear any muck from the fins, cleaned up nicely, once the paint is touched up on the front side and maybe straighten a few fins it'll be good as new. The manifold nuts/studs don't look in too bad a shape, left them soaked with a 50:50 mix of diesel & ATF, will leave them overnight but did a quick test on one and undone relatively easily, and unlike most "penetrating" sprays the homebrew mix actually creeps into the thread, the stud was wet when the nut came off. That'll do for today, hope its of interest to somebody
That looks fabulous A real thorough job. I replaced the JIS screw in mine with a cap head also. It's a crazy fastener to use in there. Hope you get lucky with the header nuts. Really professional looking paint job on the radiator....I should have begged you to sort mine. Lol. Always interested to see what others encounter when maintaining. Following. Good luck
Exhaust removed, first five nuts came off fairly easy but last one took the stud out with it, could have left it but didn't want 5 new nuts and one manky so managed to separate it from the stud with a combination of blowtorch and impact gun, I'm keeping the original studs with new copper flashed nuts. Was going to remove the Lambda sensor but it moved a bit then felt like the thread was galling, stainless, quickly tightened it back up and had to pull the connector through from behind the sprocket cover. Now part of the reason for the timing of this work was for years I've thought i had a small defect in one of the cross pipe welds, no cracking more like a pinhole, could hear the usual noise and even tried high temp JB weld years ago, which failed, but last ride out I thought the exhaust sounded louder than usual and maybe the problem had got worse. Although given the findings below maybe its always that loud and my earplugs weren't in properly, or more likely the Arrow needs repacking. But with the exhaust off couldn't see anything visually except a tiny defect were its obviously been welded from either side then meet, maybe just a slag inclusion. Thought I need more evidence if I'm going to take it to a welder, especially given how inaccessible it is, so rigged up this Heath Robinson set up to leak test. First blanked off the headers with some wood and bits of old Thruxton inner tube, knew they'd come in handy one day Was just going to blow into the other end but stepped it up another level and connected the pet dryer as an air supply. Couldn't detect any leaks from ANY welded joints, even were I was convinced it was leaking from, Oh apart from the blasted Lambda sensor now which obviously hadn't tightened up properly from before. Heated up the boss and surrounding area with the blowtorch and managed to get another 1/4 turn, tested again and thankfully no leak this time otherwise I'd imagined a leak that didn't exist and made a new one. So I'll just refit the exhaust with all new gaskets and see how it goes, been a slight waste of time and money but at least having the exhaust off has given better access to clean up the engine. Removed the areas of flaking paint and corrosion then cleaned in three stages, paraffin with a stiff brush to get the worst off, then Ammo 243 degreaser @ 20:1 then strong hot fairy liquid mix rinsed off. Mostly the patches of corrosion always start from an edge or machined face, except maybe the centre section which is likely to collect the most crap and is the least accessible for cleaning. Primed ready for painting Next I'll finish the painting then refit the exhaust, still waiting for parts, I'm leaving the radiator off until after the valve check as its easier access for the feeler gauges on the exhaust valves.
Ready to refit the exhaust with new gaskets, the paint is not a great match to the original matt finish, luckily you won't see it, had some plain matt black but used this engine enamel as its more heat/oil/petrol resistant. Exhaust back on, new copper flashed nuts are slightly taller than the oem and strictly speaking you'd want one more thread showing for the self locking action, not clear from the pic but there is a good two threads protruding, don't think there's much chance of them coming loose, usually the opposite problem Hopefully with the new gaskets at both ends and nothing found on the leak test its fixed the tiny leak I could hear, or was maybe imagining Cleaned up the pipes a bit but didn't go mad as its just the usual black discolouration rather than any serious corrosion. Next job, since replacing the chain & sprockets last year its never been as smooth or quiet as it it should with new parts, used the same JT sprockets and DID chain as the Thruxton, same person aligning & tensioning and that is way smoother. Noise is from the front so decided to try a new OEM Triumph sprocket even though its only done 2k miles, also gearbox output shaft seal has had a very slight weep for years so also replacing that at the same time. Got tired of hacking away at tab washers with screwdrivers and the like so repurposed a snapped Allen key . Impact gun makes this job and clutch removal so much easier and safer. Well worth it if you do your own maintenance, and this is only a cheap mains powered one, not been beaten yet though. The offending seal, I know what you're thinking its just chain lube but I have seen obvious oil there in the past. Old seal removed, you may or may not like my method but I've replaced hundreds of seals over the years (not on bikes) and this works fine on a blind hole, if there is enough room behind alternatively you can knock one side in and the other side will usually pop out, but not always, and its better than hammering a screwdriver or chisel through the seal to wrench it out, with a bearing very close behind. Oops, focus There is very little clearance behind the seal so don't think knocking one side in would have worked in this case. No pictures refitting as it wasn't exactly to the book, can sometimes push them in by hand but this was a bit tight and not much of a chamfer on the case, didn't have a socket (or seal driver) large enough so used the biggest I had to start it square then finish carefully with a large parallel punch around the edge. New Triumph sprocket and tab washer fitted, bit tight fitting it with the chain in one piece as normally you'd feed a new chain around the sprocket, but doable, first impression is it sounds quieter already but haven't aligned/tensioned yet, fingers crossed. Boxed up, Lambda sensor cable fed back through and made sure the pipe and cables are safe in their little house in the front of the cover. Greased the ball joints on the gear linkage when refitting. Next up finish stripping the top end for the valve clearances and new plugs.
Cheers A you can see I didn't buy it specially for this job, although the camera lighting makes it look worse, I've had it for years and don't think the firm exists anymore. Also as the engine is not actually properly black it makes the match harder, as well as my paint can see the black oil filter stands out against the engine. Its single pack etch primer and satin engine enamel, if I needed a better match I'd probably try some matt black stove/BBQ paint but not sure on the resistance to oil and chemicals. Paint and painting is one area I don't claim to have any particular knowledge on.
moving on to the valve clearances, the coil sticks were really stubborn, needed some gentle persuasion with a pry bar, used silicone grease on the rubber when re-fitting last time but it might have gone hard with the heat, may just use soapy water or a touch of oil this time. Had to cut down an Allen key for one of the cam cover screws, top right, weird I don't remember doing that last time, was nearly 6 yrs ago though. Cam cover off, hopefully the three dowels in the cam ladder either stay in the ladder or cam cover and don't fall inside. Access to check the exhaust side easier without the radiator but cyl 2 intakes hampered by the throttle body, should really get some new angled feeler gauges. Removed the timing cover to rotate the engine, can do it with the rear wheel in 6th gear but its much easier for the sake of a gasket, and needed access for the next job. Gaps were last checked at 18k and I set them all back to around middle spec, so at 27k its early for its next check and they are all still within and none have moved more than 0.02mm. @18k exhaust gaps .35 .35 .36.36 .35 .36 spec 0.325mm - 0.375mm @27k exhaust gaps .36 .35 .34.34 .35 .34 @18k intake gaps .13 .14 .14 .15 .15 .15 spec 0.1mm - 0.2mm @27k intake gaps .15 .16 .15 .16 .17 .17 Given how awkward the access is some of that difference could be measurement error or even ambient temperature, obviously engines are "cold" both times. So no need to remove the cams this time, unlike at 18k when all the exhaust valves were out of spec and three intakes on the limit, looking at the trend they should still be in spec for another 12k. Next job was cam timing, did notice last time they were ever so slightly out but thought it was too minor to correct it, this time I thought I'd have a crack, without all of Triumphs special tools. Can see here the intake cam, the slots should be level with the cylinder head and therefore also align with each other, used a shortened 7mm drill as a gauge. Exhaust not as bad but slightly out. Can only access one sprocket bolt at TDC so have to loosen one bolt move to round to TDC, lock with the timing pin (homemade) loosen the other bolt and move the cam. have got new cam sprocket bolts as they aren't supposed to be reused, come pre-loaded with threadlock, weren't particularly hard to loosen though. both in line and level now. Doubt it'll make any difference to the power, in fact I'll be glad if it just doesn't sound like a bag of spanners when I start it up "tools" made today. Short Allen key for one of the cam cover screws crankshaft timing pin, 6mm drill ground down to 5.5mm for the last 10mm 7mm drill with about 10mm lopped off for the cam alignment.
Continuing the theme of admirable workmanship there Wobbles, and a nice clear description for us less experienced owners to follow when attempting this maintenance. Did you discover if there was any indication of what was causing the coil sticks to grip, when you eventually got them out please ? I'm thinking I would probably have used a good smear of silicon grease on mine, which is now a little concerning. Perhaps a better solution would be a light covering of ACF50, as it will not harm the polymer & is also heat resistant.?
I can only think it was the grease, it definitely wasn't grease like, gone hard and crystallised, they are always going to be a tight fit though with quite a deep rubber sealing section, although last time I'm sure I pulled them out by hand, maybe I've got weaker over 6 yrs. It didn't take much force with the small pry bar under the connector, much better than trying to jab something in the rubber section. ACF50 is another good option, I'm thinking just a smear of something oil like as am sure the coils are resistant to oils etc., obviously not enough to run down the bore and contaminate the plugs.
Forgot to show pic of the timing locked at TDC with the "timing pin", also have the tensioner blade wedged as about to remove the cam chain tensioner. removing to check the spring, Sprint manufacturing sell a replacement spring instead of replacing the complete tensioner. Can see where I had to chamfer the side last service to get it to clear the frame, once its rotated anti-clockwise. As it came out, if you squeeze together the rear of the two clips you can remove the plunger and spring. Original length should be 36mm, as mine is 35mm I will be replacing it, will have to put the rest on hold as I didn't pre-order one. Can't refit the cam cover or the new sprocket bolts until the cct is refitted and I've rotated the engine a few times to double check the timing. As I can't refit the cam cover yet I tidied up some corrosion, another part you can't see but don't like refitting anything corroded or damaged. Also cleaned the calipers and changed the front pads, been happy with the DP Sport HH pads and they still had 2.5mm left after 12k miles but thought I'd give EBC HH a go as I've never tried them. If there's not much difference the old DP Sport pads will do for the Thruxton when needed, same brakes, if there is a noticeable improvement I'll change those to EBC also. Obviously no job is properly complete without a bit of polishing to finish off.
New cam chain tensioner spring arrived, length compared with the old one (bottom). refitted with new gasket and o ring There was another major job that I was in two minds over, especially after finding all the valve clearances were in spec and didn't need to be disturbed. I will make a separate post about this as well, but back when I did MY first valve check/adjustment at 18k I noticed some unusual deterioration of the surface of the intake cam lobes, I took some pictures but because there was no scoring or any marks on the buckets I decided to leave it in place but its been on my mind since. I took the decision to replace the cam at the next valve check, despite the cost, assuming I would probably have to remove them anyway to re-shim, but when I compared the condition to the pictures from 6 yrs ago it looked virtually the same and because everything was in spec I was tempted to just box it up but I'd already paid out £360 on the camshaft kit and I think I'd regret it if I got this far and didn't change it. So apologies for the rambling but long and short is, I'm changing the cam. This is the cam chain end Cyl 3, this is nearest the oil feed if that has any bearing. Edit- ignore that about the oil feed through the cam, obviously that's for the bearing journals not the cam lobes This is the far end Cyl 1 and the worst lobes, the middle ones are somewhere in between. I'm no expert but it appears to be material failure rather than contamination as there are no score marks on the cam or buckets. Locked the engine back at TDC and removed the intake cam, left the exhaust cam in position, most important thing when removing or installing the cam ladder is go gradually and evenly, there is a loosening and tightening sequence, if the cam ladder is damaged, warped or cracked in the process you need a complete new cylinder head. new versus the old, the new one is a different part no. and has to bought in a kit with a sprocket, which is also slightly different, don't know what the changes are. compared the bearing journals with a micrometer and there was no measurable difference so with some normal bedding in it should run ok. with the cam removed, buckets are fine as is the exhaust cam, another reason I don't think its been a contamination issue. New sprocket bolts have also changed, different head and T40 versus T30 on the old ones, pre-threadlocked, don't want these coming loose. Was fully expecting to have to fit it twice, once to measure then to re-shim, but amazingly all the gaps were still in spec with the new cam, a couple even nearer middle spec, luckily I'd fitted the new o rings under the cam ladder just in case. Had to redo the cam timing over again, new spark plugs fitted, Iridium plugs probably had loads of life left but makes sense while you're in there, refitting the cam cover went smoothly, reused the old cover seal, as I did last time and twice on the Thruxton with no issues, the modern rubber seals seem to maintain their condition. timing cover refitted, the downside of engine protection, even the proper triumph ones, once they're on you're stuck with them, although the clutch cover is still perfect under the protection, if I had a crystal ball I would have spaced it off with some washers. Starting to put things back, a bit cleaner now, had to backtrack a few times forgetting which order or what goes under what, put everything back before Id forget to feed the fan connector through the rubber shield. Wiped a light smear of oil instead of silicone grease around the top of the coils before pushing them home, used silicone grease last service and they were really stuck. Biggest pita is the throttle cable bracket, I'm sure its for safety but its a nightmare, have to fully wind back both nuts to remove because of the "claw" design, then can't turn the back nut when its in place so you have to estimate where it needs to be before inserting in the bracket, if it needs moving even one turn you have to wind them both completely back to remove it and start the process again Airbox and tank refitted, only just replaced the air filter <500 miles ago, coolant added, spun it over on the starter to get some oil circulated then this is the actual first start, thankfully doesn't sound like a bag of spanners, bit of cam chain noise as expected for a few seconds but even that wasn't too bad considering the cam chain tensioner was completely drained of oil. Run it up to temp a few times to completely fill the coolant, after a few heat cycles got a small turn on the manifold nuts, then replaced the oil and filter with Motul 7100, been running it in the Thruxton last year and the engine/gearbox feel smoother so its my go to oil now. Initial impressions are engine feels and sounds fine, no leaks of coolant/oil from any joints or hoses. The "noise" I could here, or though I could, form around the headers seems to have diminished to the point were anybody else would say, there's nothing there, its normal. Next bodywork back on and test ride, not sure on the running in procedure for new cams but will try and keep it below 6k for a few hundred miles at least.
First test ride, taking it steady with the new cam but so far engine sounds and feels better than ever, the exhaust noise I could hear (assumed it was a leak) has gone and for a Brucey Bonus, the new Triumph front sprocket has got rid of the drivechain whine I've had since fitting new chain & sprockets last year, not sure why as never had an issue with JT sprockets before. So it's been a lot of work but its a win, win, .......win at the moment, I think I may have put the gearchange arm back on one spline out as it feels low but that's not a bad result with everything I'd done. Couple of very small jobs I forgot to add, replaced the fuel filler cap seal (Sprint manufacturing) and also the oil filler and dipstick O rings, no leaks but they were rather flat. Also changed front brake fluid and bled after fitting the new pads, including ABS bleed & master cylinder. Only thing left I've not managed to solve yet is the rear brake is dragging, disk is very hot at the end of a ride. Not from this service, been like this a while. I know its not me on the pedal and I've checked/cleaned/greased the caliper a few times, only thing left i think is the master cylinder, may look at a rebuild kit unless anybody has other suggestions.
It's not the same, and it won't be applicable in your case, but as you have checked the caliper piston is moving freely,,,, Fwiw I had my rear brake binding slightly, and could not figure it out. Both my caliper & piston moved freely, pads were healthy & also moving freely, yet when it was on the bike the disc was still very hot all the time. I first noticed it when commuting on her, the week after our Forum Trackday in about 2012 @ Oulton iirc. Anyway, I'd had a bit of a lowside. Nothing dramatic, just picked up some turf & shortened the frame slider. It didn't stop my day once the medic's had authorised me a new wristband. However my "largely unharmed bike" had actually taken a knock on the rear caliper, and that had actually slightly bent the aluminium bracket that the caliper is mounted on. It was not much (the bracket still cleared the disc, and it's pretty close already) but it was enough that the caliper must have been out of line with the disc & hence dragging. A replacement bracket was purchased from the bay of fleas, and as soon as it was swapped the heating disc issue disappeared. Like I said, can't see it being even remotely applicable to your issue, nonetheless
Thanks for the reply, without a crash I can't see how my bracket could be out of line, when its up on the paddock stand there is no drag on the disk, something is happening during the ride and I suppose it only has to drag slightly to heat up the disk, if its constant. I have a vague recollection that it started after I serviced it last year and bled the brakes but I may be wrong, but I've re-done it a few times since with no success, its even wearing the disk but still has the original pads after 27k miles, so I'm not a heavy rear brake user. I may take the wheel out and check everything yet again, including bracket, wheel spacers, bearings, check the disk for runout, if I don't find any difference then it only leaves the master cylinder maybe locking pressure in the line. I suppose I could go out for a short ride and not touch the rear brake at all, if it still gets hot then its probably not the master cylinder.
I had an issue with the brake piston on the rear getting hot during riding because it was dragging, turns out the pedal was ever so slightly 'on' when I'd assume it was off, so had to adjust the nut so that it came out a bit more. But I was using aftermarket rearsets. In the end I did a full rebuild and replaced the pistons seals and never had an issue since. If I had the money I'd go buy the pistons from JP brakes https://jpbrakes.com/ because they've got a fancy design that reduces drag on the pads, been watching them for ages and race teams are finding absolutely no brake fade from the new design pistons. But I'm sure a rebuild and new pistons may solve the issue
Small update regarding the rear brake, turns out it was largely my fault and my assumption that the caliper was moving freely was wrong and I hadn't done as good a job as I thought on the sliding assembly. Stripped it again and found some dried up grease at the base of the holes, no doubt accumulated over 10yrs, did a thorough clean with brake cleaner and cotton buds, re-assembled with Silicone grease, not too much that it 'hydraulic locks' the pins. Sliding lovely and free now but pins now acting like little air cylinders and pushing the caliper back towards the disk, held it over for about 5 secs and a little fart of air escaped past the pins and the seal, and caliper now working as it should. Have done a few more test rides since and all seems ok. That's the last gremlin sorted and the bike feels as good as ever, opened her up a bit more now I've put a few hundred miles on the new cam, also the 'chain' noise has gone altogether since swapping the JT front sprocket with the Triumph oem sprocket.
