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ranton_rambler View Drop Down
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    Posted: 25 Mar 2023 at 08:08
Without going into all the reasons, I am going to replace the big end shells in my 850GT.
I’ve dropped the sump and realised it’s not quite like a Tonti motor in that the oil pickup obscures access.
Anyone with experience who can tell me if it’s more work to fiddle about around the oil pickup, or bite the bullet and take the front cover off and remove the oil pump gear, so that I can take the pickup off? Unfortunately the bolts which hold it on are screwed in from the outside.
Ian
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 10:19
I replaced the big end shells on the V7 Special when I changed the barrels.I can't recall in detail exactly what the procedure was but I know that I didn't remove the front cover. Any help ???
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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ranton_rambler View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 11:00
Thanks Dave. I guess that confirms I should be able to get a socket on the nuts to undo the caps, but I am not planning to take the heads off so I’m not sure if I can get the shells out of the rods. We’ll see…

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 11:10
Just a thought Ian, but if the shells were so badly worn as to cause vibration, would not the oil pressure drop enough to put the warning light on.?
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Simond Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 15:07
Mine were, or at least one of mine was, utterly knackered.  The other one was fine, and no, I don’t know how that’s possible, there were no blockages, the shells had the same markings, I’d guess they were the same age, probably original.  The oil light didn’t flicker, and yes, the light does work properly.

The engine made a noise like something up top had gone, not the kind of heavy knock you’d expect.

It’s a LeMans.  Replaced shells, and the camchain whilst I was in there, put it all back together and rode it to Mandello and back two-up.

All very curious.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 15:53
I don't know about a noise as I ride with earplugs, but there's a lightish vibration through the footpegs at certain range of engine speed, (and it's not the UJ before anyone chips in with that!).
Your post give me hope that I'm on the right lines - I've checked everything external to the motor that I can think of. What was your crankpin like?

I guess oil pressure can be maintained (at least above the switch setting) if the pump can deliver enough flow to keep up with the higher leakage rate from one big end being a bit slack.
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 25 Mar 2023 at 16:10
Another thought Ian. If it turns out not to be the big ends it would be worth removing the timing cover and checking the security of the timing gears on their shafts. Years back when I replaced the crankshaft oil seal on the V7 Special I discovered that the oil pump gear wasn't fully engaged on its shaft because the woodruff key had been partially displaced in its slot when the gear was fitted.It was a relief that the key hadn't failed altogether leading to a lubrication disaster.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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ranton_rambler View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 20:18
The caps are off and shells are out. It doesn't look too bad but I'll replace the shells anyway.
Getting it all back in again should be fun!

What's the opinion on the nuts/bolts? I am sure I once remember reading that they are stretch bolts and shouldn't be re-used, but torque value seems to be the standard M10 value, and none of my workshop manuals mention using new bolts.

(Correction - they are M8 fine pitch in my engine)

Ian


Edited by ranton_rambler - 27 Mar 2023 at 21:01
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Post Options Post Options   Thanks (0) Thanks(0)   Quote johnno Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 21:00
A few years back I was told by a dealer you need new bolts  but the bike was different to yours if you can get them I would change.

1100 sport corsa , Yam R1, guzzi 650tt rider
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 21:44
I seem to recall reading somewhere that B/E bolts can be re-used along with new nuts. When I did the job I used new bolts because that was the recommendation for Triumphs, Norton's etc when I worked on them. So I carried the principal over to Moto Guzzi. Had I not done so I think I might have become nervous as the tachometer needle climbed the scale.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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ranton_rambler View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 22:03
Where did you get them Dave? I think mine has the early type, presumably the same as yours.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 22:05
Gutsibits have them. I got mine from Stein Dinse but they no longer list them.

Gutsibits/Engines/ page 11.   Special order!!

Edited by Dave P. - 27 Mar 2023 at 22:20
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 27 Mar 2023 at 22:22
And here.https://www.harglo-performance.com/genuine-moto-guzzi-connecting-rod-big-end-bolt-gu30062200-18517-p.asp
Bolts cheaper than Gutsibits but no nuts listed. Gutsibits have the nuts.

Edited by Dave P. - 27 Mar 2023 at 22:34
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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ranton_rambler View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ranton_rambler Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 2023 at 12:39
Originally posted by Dave P. Dave P. wrote:

And here.https://www.harglo-performance.com/genuine-moto-guzzi-connecting-rod-big-end-bolt-gu30062200-18517-p.asp
Bolts cheaper than Gutsibits but no nuts listed. Gutsibits have the nuts.
I think they may be the wrong ones for my engine Dave - will double-check tonight.
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 2023 at 14:14
Interesting, the part number is the same as the number on the Gutsibits site.
I'll be interested to see what you find.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

1971 V7 Special. 1972 850GT.
1970 T120 Bonnie. 2009 500 Bullet.
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