Hi from London England!

[Rob Frankham]

A lot can be told by the nature of the squeak itself. If it's continuous, that's not much help but if it is someting that fluctuates, then the frequency of the fluctuation should give a fairly reliable indication for where it comes from... if it fluctuates in time with the rotation of the wheel, then it probably comes from the wheel bearings or brakes. If it fluctuates with the engine revs, then you need to look at the engine, the clutch or the gearbox (input side). If the fluctuation is faster than,but varies proportionate to road speed, you're looking at the gearbox, or rear drive. A squeak that is intermittent but coincides with a certain sort of road surface isn likely to be suspension.

You say that the noise is coming from the front of the bike and this is probably the case but noises from a bike in motion can disconcertingly originate from somwehere other than where they seem to. What I'm trying to say is, don't assume it's from the front. It's possibly coming from another part of the bike.

Rob

[Ade B]

Thanks Rob and Steve

Its still early days - as a cyclist I'm familiar with chasing noises down to unexpected sources, your points noted. Will give the squeak some further attention next weekend.

Cheers
Ade

[Ade B]

Took it out for a run yesterday, it is lovely through the rev range in open road riding but hold it at 4000rpm for a minute or so and it bogs down, refusing to pull until I back off the throttle below 3000 rpm and then gradually bring it back up - even then it is intermittent with surges and rough running... A bit of a hairy ride down the M23 to Gatwick and back (need to find a closer bit of motorway!).

The squeak is still there and intermittent, audible when sub 2000rpm and tootling along at 20-30mph - it is independent of engine speed and happens in neutral so I suspect wheels/brakes or suspension.. one for another day.

I stripped down the RHS Bing this afternoon - this may be the culprit:



cleaned it all up, replaced the diaphragm... the old one looked fine but was a bit thinner and less elastic than the new one.

Put it all back together and fired up the bike. I reset the main needle to 2no. clicks out (2nd position)? as per Haynes and set the pilot jet 1.25 turns back from closed, ditto the mixture jet following a bit of googling. The tickover needed to be reset using the the throttle stop and I got it to sit at 1200rpm when warm. I'm not entirely convinced I've got this correct but it seems to run ok and the engine responds well to blipping the throttle. Can I mess up the mixture?

I'm going to repeat the exercise on the LHS this week and then rewatch a couple of youtube videos to check the 'stock' settings and then take it for a run.

Final question - what do folk use as a 'drift' to get the float pin out? On mine, it wouldn't shift and I was wary of damaging it.. suggestions welcome.

Cheers

Ade

[barryh]

The pin usual comes out easily but look carefully at it, one end is serrated and you want to be pushing out from the other end. Take care not to use too much force as it will break the casting. As a drift I use anything I can find that's thinner than the pin.

[Tom H Ca]

A nail smaller than the pin with the tip cut off to make it flat will do fine.

Tom

[Ade B]

Thanks, will grind the tip off a nail for the 'drift'

[Rob Frankham]

Whereabouts in the Big Smoke are you? I may be North of the Border now but I was born and bred in Surrey. The M23 was always on my test route...

Rob

[Ade B]

I'm in SE25 just below Crystal Palace. Think the M25 offers slightly less distance between junctions now I've looked at a map!

Cycle around Surrey/East Sussex/Kent a fair bit. Lovely part of the world.

[Ade B]

Rocker cover gaskets and carb kits arrived this week so this afternoon saw some fettling and just back from a test drive.

Had some fun finding the OT marks for TDC and then after attempting various methods to work out which side was actually at TDC, I rested on the technique of whichever side had the slack on the rockers at TDC was the side which was correct.

There was a bit of vertical movement in the rocker assembly on the intake to the LHS and both intake and exhaust on the RHS so I tightened those up following a couple of youtube guides, torquing up the headbolts to somewhere between 25 and 35 Nm to avoid overtightening. I don't trust my cheap torque wrench at lower numbers so erred on the side of caution. Assume that if it doesn't leak oil, all is well. Will keep an eye on it.

I then sorted the valve clearances, 0.15mm on the intake and 0.20 on the exhaust. The intake needed a tweak on the LHS, was fine on the RHS so a left it be, exhaust was a bit tight on both so backed those off slightly.



Fired the bike up afterwards and all seemed ok after a few coughs and splutters (first start in a week).

I then took the LHS carb off and stripped it down. The main jet was much cleaner than the RHS, I replaced the diaphragm and O rings to the pilot mixture screw and pilot jet as they had failed, also replaced the main jet holder O ring although it looked fine.

I didn't touch the throttle butterfly or choke assemblies as the bike had been idling and running perfectly up to 4000rpm, and dealing with the peening on the butterfly screws didn't appeal. Might need to revisit.

This time I noted the turns from fully closed on the pilot jet and pilot mixture screw. The pilot jet was fully closed, the pilot screw was 1 turn out from closed. On reassembly I set both at 1.25 turns out from closed. Is this correct for the idle jet?

Put everything back together, I'd taken some care with the throttle and choke cables to disturb their positions as little as possible.

Fired the bike up and it idled lumpily - adjusted the LHS throttle stop until it seemed less lumpy and then closed the idle screw until the engine stuttered and backed it out until a regular tickover was reached. Got to a consistent warm tickover of around 1000 - 1100 rpm, which is where the red charge light drops out.

Took the bike out for a run, a warm pleasant evening here in the SE. Immediately it was clear I've upset the low RPM running somehow, the bike was lumpy in traffic under 3000rpm where previously it had been totally smooth. It wouldn't pull smoothly up to higher rpm but at higher throttle openings seemed ok and pulled cleanly to the red line.

Once I got to open roads, and above 3000rpm, it was great. Pulling cleanly and strongly through the gears up to an indicated 70/80mph where I safely could. I didn't have my phone in the tank bag so couldn't check actual speed, I've noticed the speedo significantly over reads, probably more so now I have a diddy 110/90 on the rear.. I had some fun on sweeping A roads for a few miles.

I got onto some dual carriageway and opened up in the top gears, the bike pulled well over the legal limit (if the optimistic speedo is to be believed). Where previously it bogged down, now it was fine to hold rpm over 4000 where ever I set it. Result!

Coming back into the city via Croydon things took a turn for the worse, under 3000rpm the bike was progressively less tractable and refused to rev, running very roughly and feeling like it was running on one cylinder at times. I had some mild backfires and eventually, close to home, the bike backfired loudly and then with just over 100 miles on the trip from the last refuel, conked out.. I set it to reserve and it made it to a petrol station and then home without any further backfiring.

During the ride, at times there was a strong smell of petrol, and there seems to be fuel weeping from the idle screw area of both carbs. This and the low miles until hitting reserve suggests fuel is leaking somewhere. I checked the hoses and there is nothing obvious but running my hand under the carb will produce some petrol on my fingers..

So to summarise my rambling post:

Before messing with valves and carbs, the bike ran perfectly to about 4000rpm and then bogged down at motorway speeds. It would pull cleanly from tickover in 5th gear, even with a pillion, up to 4000 odd rpm or an indicated 60 - 70mph.

Since I've adjusted the valves and stripped and cleaned both carbs, replaced O rings where they have failed and both diaphragms, I now have a bike which was lumpy from tickover to 3000rpm in any gear but once opened up ran well at higher rpm/speeds. After a 40-50 mile loop, returning to urban riding, it ran terribly in traffic.

I expected to need to balance the carbs following fiddling them but I think something more is afoot. I changed the cork gasket on the LHS carb float bowl, I noticed the fit was poor compared to the gasket I removed would this upset anything?

At least the squeak seems to have gone which is a positive

Would welcome thoughts.

edit - from a bit of googling, think I need to screw the idle jets fully closed... will have a tinker tomorrow.

edit again - so popped the float bowls off and in the RHS was sat an idle jet!! So that may explain the poor low speed running on the way home.....refitted and nipped both sides up. Also noticed that the fuel tank filler cap seal has broken... One in one out....

Ade

[Kurt in S.A.]

I've never liked the notion of finding the side with the loose or slack rockers to figure out where I was. If the valve clearances were set wrong the previous time, then you're starting off from a bad spot...they could be so tight there's no slack or their both too loose with too much slack. With the valve cover off and the spark plug out, put your thumb on the plug hole and turn the engine. I usually put the bike in a high gear and sit on the left side of the bike. I rotate the rear wheel while watching the valve action. When I see the intake valve come open and then begin to close, I'm beginning the compression stroke. I then begin to feel some pressure against my thumb. At that point, I slowly bump the rear wheel until I see the F-mark, the S-mark, finally the TDC mark. Now I'm ready to set the valves on the left side. Once set, rotate the engine 360 degrees...the next TDC mark on compression stroke will be for the right side. Or you can watch the valve action and plug hole pressure on the right side to confirm. Once at TDC for the right side, set the valves.

Kurt