Some servicing – 24 March 2016.

I’ve been busy with Rhino but that doesn’t mean I’ve been neglecting The Fire Bike. A week ago I noticed that I’d covered 3000Km since the last oil change so a quick service was in order.

Engine oil was changed and examined for any nasties and found to be surprisingly clean. The usual checks of cables were made and the clutch free play adjusted. The generator belt didn’t need adjustment and the spark plugs were in good condition.

This bike seems to have the noisiest valve gear of any Guzzi I’ve owned. I know “A noisy tappet is a happy tappet” but this is something else. I decided that a close check of the clearances was necessary. The usual adjustment procedure was employed and, to my surprise all were “spot on”.

My workshop manual gives 2 values for clearances. At the beginning it states 0.1mm inlet and 0.2mm exhaust but then has an update for later models of 0.15mm and 0.25mm. These are what I use as this update coincides with the change to Dellorto carbs which my bike has. I’m not going to reduce clearances as that way lays the route to a burnt valve.

My experience with old cars was that, after a high mileage, the face of the rocker can wear at the point where it contacts the valve stem. This means there is a hollow and setting gaps with feeler gauges will result in wider clearances because they can’t measure the true gap. So, I slackened everything right off and peered at the faces of the rockers – all good. I’ve no idea what is causing all the clatter. Initially I had put it down to the leg guards and fairing reflecting back the noise but a friend had commented on the mechanical noise after I rode past him the other day.

The other service task was to check the contact breaker gap and ignition timing. Before I could do this I needed to replace the missing distributor cap retaining clip. This had gone missing last summer and has been temporarily secured with a cable tie since then.

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I ordered the replacement parts ages ago but they’ve stayed in their packet till now because the distributor needs to be turned to fit them and the timing would be lost.

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In the next picture you can see the temporary screw and lock nut fitted at the 7 o’clock position.

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Having removed the distributor cap, I slackened off the clamping screw after marking the position of the distributor with a permanent marker.

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This gave me access to replace the fixing screws. My new replacements are stainless steel. Here’s new with the remaining old one which will be stashed on the bike as a spare. To be on the safe side, the threads of the new screws were treated to a spot of Loctite.

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The distributor was lined up with the marks I made earlier, contact breaker gap and ignition timing checked, and the cap replaced.

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Should be good for a while now.

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Spokes – 21 Mar 2016.

My new spokes and nipples arrived. I had foolishly thought that I could cheat and just change the nipples and tighten everything up. I should have known it couldn’t be that easy! The replacement spokes are not exactly the same.

The threads are different and the thicker, butted part of the spoke is longer.

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You can see in the last photo that the original spoke has been cut. I had tried to drive the old spoke out of the hub by hitting it at the correct angle. I tried large amounts of heat as well as soaking the parts in dismantling fluid. They moved a bit but no more. I spent time knocking them back and forward but, in the end the spokes got bent.

I put the wheel in the car and visited my friend Bunny for advice and moral support. We sawed through the spokes so that we could bash the thick section with drifts inserted through the rim spoke hole. It took some time but we got them out. In the process another spoke nipple let go and a third spoke had to be extracted.

Back in my workshop I fitted the new spokes with out difficulty. I then went around all the remaining spokes, slackening them off then re-tightening them the same amount to make certain that no more were about to give up the ghost.

The three new spokes are the ones with brown tape on. There are no bent spokes but there is some photographic distortion.

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I mounted the wheel in a borrowed stand and tightened the new spokes so they “rang” like all the others. Lo and behold, the wheel is now straight. That was remarkably painless.

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I’ve kept the one broken spoke set so that I have a pattern when I search at shows. It would be good to get some original type nipples given that I have four wheels like this.

It looks like the cause of the broken nipples was corrosion. It has been suggested that use of an acid cleaner can do this as it’s near impossible to wash it out properly.

This morning I got the tyre refitted. I didn’t even bother to try to do it myself this time. The wheel was back in by lunch time and ready to go.

This afternoon I went out for a 40 mile “shakedown” ride, calling in on Pete who painted the tank and toolboxes back in June 2014. I had expected to have Rhino back on the road this time last year but my crash and the purchase of The Fire Bike put things back.

I had set out with pockets full of spanners and nuts and bolts “just in case”. This proved to be a good idea as the gear lever dropped off the back of the gearbox in Lampeter high street. I emptied my pockets but couldn’t find a 10mm spanner so had to invest £1 in one from the local cheapo shop.

Other than that, all seems to be good. The bike goes really well. However, I’m showing some mechanical sympathy and not giving it “the berries” while there are still new engine parts to be run in.

Rear wheel bearings – 10 Mar 2016.

I said I would be checking out the rear wheel bearing adjustment next. The MOT tester had agreed with me that there was a bit more play than there should be. The rear tyre had to come off anyway and there is a spoke to adjust so it seemed sensible to look at it now.

First, I made up a bracket out of scrap aluminium to mount my dial gauge on the bevel box so that I could see just how much play there was.

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I marked the rim of the hub so that I did all my tests at the same point then set the gauge to zero(ish).

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Then pushed the wheel in,

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and out.

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The total movement was about 0.16mm. There needs to be some movement to allow for heat expansion. The figure I have is 0.05mm.

I removed the wheel then took the tyre off. This involves removing the brake cable and the brake torque arm from the brake plate. Getting the wheel out is helped by the flip-up rear mudguard section as you only need to have the bike on the main stand.

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However, getting the brake plate and wheel out of the swinging arm and past the left shock absorber is fiddly. When mounted, the brake plate sits in this position (I took this photo later when the tyre was off).

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I find the easiest way is to remove the torque arm completely then turn the hub like this before removing the axle and pulling the wheel off the drive splines.

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When I removed the manky looking rim tape the heads of two spoke nipples fell out! I removed the rest of the nipples and ordered some replacements.

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So back to the rear wheel bearings. I knew from my notes that the two spacer shims currently fitted were 1 and 2mm. I ordered 1.5, 1.4 and 1.3mm shims so that I could reduce the combined size by 0.01mm at a time. I had also ordered replacement oil seals because I knew they would be ruined when I took them out.

I’ve covered the assembly of the wheel bearings in an old post here so I haven’t taken pictures of the process this time. I levered out the oil seals and the bearings came out easily.

I rechecked the thickness of the original and replacement shims then changed them to give a combined thickness of 2.9mm instead of 3mm. I reinstalled the wheel and brake plate without fitting the oil seals and tightened everything up.

Using my dial gauge again the free play was about plus and minus 0.02mm giving a total of 0.04mm. I was happy with this so the wheel came off again so that I could press in the oil seals and finish the job.

I’m now waiting for the spoke and nipple sets to arrive before I can go any further.