THe Bertha saga continues!!

[Flipfly]

Righty ho, took Bertha for a new pair of inner tubes as I was sick of the tyres going down, lol.

Anyways, filled with fuel and had a pleasant ride over to Steves at F&B Tyres, but the bike seemed a little lacking and spluttering like fuel starvation still. So when the tyres were done we checked the timing and it was a little out.
On the ride home she was definately alot better, pulls much better and less spluttery, but still chugged a little after holding 85 ish for a minute or so. She seemed to recover a bit quicker though, so we're definately moving in the right direction.

Now, I know that last year we dropped the needles a few notches so I'm wondering if it possibly is running too lean at the top end now?? I suppose I should do a plug chop, but not sure of the best way to do this.

My nextdoor neighbour but 2 has access to a ultrasonic cleaner, so would it be a good idea to strip and clean the carbs to try and cure this spluttering. It's really just this and the rattle on the left hand side that is holding the old girl back now.

 

[Flipfly]

Rattle is actually on the Righthand side

Does anyone know where there is a cheap right hand secondhand cylinder head available (prefefably with the rocker gear). I just figure it's worth a try. If mine is fooked I'll get them both overhauled.

59 views and no comments worries me guys, have you all given up on me now

 

[Voyager]

59 views and no comments worries me guys, have you all given up on me now

I suspect its just that there are no magic cures to those sort of performance issues, its just a matter of working your way through all the possibilities until the problem disappears .

Regarding the rattle . . What are your cam followers like ?? if they have done over 100,000 miles I would replace them before thinking about changing the heads.

Ultrasonically cleaning the carbs can only be a good thing - even if it doesn't cure the performance issues .

Have you checked the sock filters on the fuel taps ?? they can become bunged-up and restrict fuel flow (its a long shot though).

After that its coil connections, plug leads, new plugs, tappet clearances, rocker end float . . all the usual suspects .

Keep us posted .

Bob.

 

[Shep]

59 views and no comments worries me guys, have you all given up on me now

We look to you as a leader of men, not as a sheep

 

[Flipfly]

The cam followers were installed by Scriminger when he rebuilt the bottom end (less than 3,000 miles ago) and they looked ok when Rob and I had the head and barrel off.

The rattle definately seems to be top endy imho. All the rocker gear looks good, everything shimmed up correctly and the bearings are good.

My concern is dad had the valve guides done and I wonder if there is an issue there. The only thing that Rob and I didn't do is remove the valves and check the guides. I'm a bit of a numpty regarding these things, so I figured that fitting a replacement head would maybe point in that direction so I can then send the heads of to be sorted.

The other side ticks away nicely as it should do (not silent, not noisey, just clickety clickety like a badly oiled swiss watch hehehe). The rightside is way too noisey. It really does sound like the tappets have a 3mm gap, but it's not the tappets as they have been done.

I'll get the carbs cleaned to sort out the fueling and see if that solves it. I'll also replace the HT leads and see if that helps too, but I'm fairly sure it's fuel starvation, or she's a touch lean.

 

[Flipfly]

We look to you as a leader of men, not as a sheep

Should have gone to specsavers

 

[SeanW]

I had a similar problem when i rebuilt mine - nasty noise from right side. Unfortunately I never really worked out for sure what it was.

I just stripped it and built it back up again extra carefully; and the noise was gone...

One odd thing I noticed was the end of one of the rocker arms was a tiny bit burred and so wasn't moving completely smoothly on its shaft - so I cleaned the burr up with a file. I eventually worked out that the burr was probably caused by a cylinder stud nut being put on upside down at some point (wasn't me, honest!).

I also went through a phase of paranoia about the rocker cover being on upside down and the rocker contacting the cover (sure I read somehere about this being possible, though recent thread on this forum says otherwise)

probably no help at all....

 

[Voyager]

The rightside is way too noisy. It really does sound like the tappets have a 3mm gap, but it's not the tappets as they have been done.

I'm sure if Rob has been there it will be fine . . But . . I have in the past seen wear on a rocker arm where it contacts the valve stem (not on Airheads admittedly). This means that when you slide the feeler gauge in you are adjusting to the unworn sides of the arm, not the contact point and the tappets end up too wide.

Bertha has done a high mileage and has had some abuse - next time you adjust the tappets just make sure its not a worn rocker causing a slack tappet.

Bob.

 

[Rob Farmer]

Phil s cylinder was noisy so we took it off and exchanged it for a 2nd hand one from Richie Moore, while we were waiting for the replacement to arrive I lent Phil a cylinder from a project bike, this was nice and quiet, Phil ran it for a week until the replacement arrived unfortunately the replacement was as noisy as Phil's original.

 

[Flipfly]

Phil s cylinder was noisy so we took it off and exchanged it for a 2nd hand one from Richie Moore, while we were waiting for the replacement to arrive I lent Phil a cylinder from a project bike, this was nice and quiet, Phil ran it for a week until the replacement arrived unfortunately the replacement was as noisy as Phil's original.

I'm still wondering if it might be those bloody stainless pushrod tubes

When we exchanged the barrel yours had the original steel ones. Just thought I'd try an alternative head as the noise still seems to be more at the top end.
Maybe I should wait for the airhead weekend, pick a bike that's quiet and do a midnight exchange

I just can't see it being the actual barrel because Rich checked the replacement and he would know if it's right. We refitted the pushrod tubes in the new barrel, could they cause the rattle?

 

[Flipfly]

Having a trip into Lincolnshire tomorrow in the piddling down rain.

I have confidence that when she returns she will purr like a Kitten.

I've given up, time to call in the experts

Shame she won't be getting a facelift

 

[Flipfly]

The experts verdict......"oooh, that sounds like a steam engine" lol

Miserable weather from Stoke to Sleaford, but the bike ran really well and didn't stutter once

Still sounded like a bag of spanners though.

I have been assured of receiving a swiss watch when I return to collect her. The rebuilt gearbox is a revelation (thanks Bob). It just gets better every time I ride the bike.

Hopefully the Airhead weekend will now be spent helping others and having a laugh whilst Bertha sits quietly outside. Will update you all with the findings once the inspection is complete

 

[Voyager]

The rebuilt gearbox is a revelation (thanks Bob). It just gets better every time I ride the bike.

Glad to hear it .

Its always a relief to hear that everything is OK.

You'll get to Southern Spain yet .

(Andy Frizzle just e-mailed to say that his gearbox - with the high fifth gear fitted - is very smooth. Phew !!!).

Bob.

 

[Flipfly]

Glad to hear it .

Its always a relief to hear that everything is OK.

You'll get to Southern Spain yet .

(Andy Frizzle just e-mailed to say that his gearbox - with the high fifth gear fitted - is very smooth. Phew !!!).

Bob.

I am very grateful to both you and Rob for the help. Robs head bearings are great too, at least she handles properly. If Steve can sort out the rattles I think she will be a pleasure to own and ride. If I can source the right nose for her she might even become beautiful too!
It's a bit off putting seeing children burst into tears at the sight of her. I have to park her so that it's her bum showing, otherwise people cross the road to pass her, lol

 

[Flipfly]

OK, time for an update.

Spoke to Steve ref the bike and he said, "nowt wrong with her engine, she runs like a dream!!!". Confused I wondered if his hearing had gone, but it turns out, he was talking about her current state, not the one he received her in

The list of parts (so far!!)

4 Cam followers. Turns out he didn't install them when he did the bottom end and they were all fooked.

Used pushrods - Apparently the pushrods were all looking worn where they meet the cam followers too.

New ring set on both pistons. The oil ring was in the wrong way up on one side and the other side were out of tolerance.

Exhaust valves both sides. The guides are fine but the valves had got a ridge in them stopping them seating correctly. All valves re-lapped.

One of the rocker arm needle roller bearings was missing a needle (who knows where it's gone

The ignition unit had no shims in it causing erratic timing issues. Re shimmed.

Charging system was all new, but a poor wiring connection was hindering it's performance and the battery was on it's last legs.

Air box lid replaced as the intakes were cut down and Steve reckons this cocks up the airflow at high speeds (relative to the max speed of a sheddy old BM that is, lol).

The next issue is with the play in the rear end, let's see what happens there, but there is a concern about the crown and pinion pushing together and "overmeshing" if that makes any sense.

I think here 8,000,000 abusive miles have taken their toll

 

[Kenny]

Blimey flip, make sure they put it on a revolving pedestal, for all to gaze at, the Wee-Kend rally Serious rebuild there

Me, removed those Jerry clean air tubes etc today and thought I was doing well

 

[Flipfly]

Blimey flip, make sure they put it on a revolving pedestal, for all to gaze at, the Wee-Kend rally Serious rebuild there

Me, removed those Jerry clean air tubes etc today and thought I was doing well

Well Kenny lad, ya can't fook about. It was either get it sorted or set fire to it

Still awaiting news of the bevel box

 

[Flipfly]

Sorry about the quality of my typing guys. Just noticed the number of mistakes I make in some of my posts. Less haste more speed

 

[Flipfly]

News from the Bevel box.....................


Yep, that's fecked also, lol

Bearings need replacing, main bearing cage was falling apart so lucky that it got looked at when it did.

Nobody laughed when I said triggers broom, hopefully you understand now.

Looks like the bill will be around a bag of sand!!!

Nevermind, as long as she runs nicely and doesn't explode upon opening the garage door it'll all be worth it

 

[Flipfly]

Unfortunatley I'm not going to get to pick her up this weekend as we have no one to look after Sophie. But I thought I'd tot up the damage in parts. I don't even want to consider the cost, I'll leave that for the wife to discover and shout at me for

Parts list:

2 x Cylinder Head Gasket
4 x Push rod Grommet
4 x Crankcase Stud o ring
2 x Barrel Base O ring
4 x Gudgeon Pin circlip
2 x Piston ring set
4 x Cam followers
2 x Exhaust Valve
4 x Used Pushrods
4 x Con rod bolt
1 x Alternator oil seal
1 x Timing chain gasket
1 x oil filter
Engine oil
1 x Roller Bearing (ouch, these are fecking expensive!!)
1 x Bevel Crown bearing
1 x Pinion input ball bearings
1 x Pinion input oil seal
1 x Final drive seal
1 x final drive O ring
Gear oil
1 x Battery

Don't forget all the previously renewed stuff

Rebuilt engine bottom end. Rebuilt using good used stock, replacing everything bar the outer casings!
Valve guides
Stearing head bearings
Timing chain
Timing chain gear
Replacement Barrel
High output diode board
Stator
Rotor
Re-wire
Bevel box pivot bearings
Rear shock rebush
Gearbox rebuild (Cheers Bob )
New throttle, clutch and choke cables

All I need now is a new set of wheels and a new frame and I think we have a complete motorcycle