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654 Barn find

13K views 40 replies 13 participants last post by  Kevin S 
#1 ·
Hello All,
I have just acquired a 654 which has been off the road since 1985. It appears to be complete but the engine is in about 100 pieces. It was dismantled because it dropped a valve which then made a hole in a piston. But hey, it was a very good price, and I have always liked Benellis.
I'm very keen to get this one back to its former glory, and I'm hoping that it doesn't need any unobtainable parts.
 
#5 ·
Hi Richard, You just can pop up on here with half the story, where's the before picture. And don't worry about boring us to death with a bolt by bolt picture story of the restoration. We love that sort of thing.

welcome and nice find:clap:
 
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#6 ·


I reckon he's not coming back.
:confused::confused::confused:




I've had my crystal testical out. :p

I've forseen............:blur:..........he's already paid £2300 pounds for it, going to spend another £2000 getting running rough, then sell it for scrap and buy a Trumpet.:rolleyes:


Oh crap..........that was me. Kick me in the crystals someone for doing it.:doh:

 
#7 ·
No, I haven't run away, but I have been busy taking stock of what I have taken on, and making a list of what I will need to buy. The bike apears to be pretty much complete, with the top half of the engine in boxes. The silencers are completely shot, so I'll need a pair of those. As I said above, one valve dropped into the combustion chamber and buried itself in the piston, so I'll need to find those too. I will probably get a whole set of valves, and I'm hoping somebody on this forum can tell me where I can find them.

The carbs were sitting on what was left of the engine, but still attached to the throttle. The previous owner pulled them off the airbox woithout first undoing the clips that hold them on. This means that all four of the rubbers that connect the carbs to the airbox are torn to bits. I'm sure they will make an interesting treasure hunt. Again, if anybody can point me at a supplier, I'd be very grateful.

Some pictures. I thought you might like to see the insides of my carbs. They had been sitting for nearly 30 years, and some still had petrol in the float bowls. I had heard that carbs can get gummed up if left, but this is ridiculous. The insides are full of a nasty sticky mess which is a cross between mud and paint. Completely lacquered !! I can feel a trip to an ultra sound cleaner coming on. I've never tried that before, but I have seen pictures, and it looks like it should work. Again, if you have any opinions on this, please let me know.
 

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#9 ·
Get a piece of paper and make a "to do" list. This list will grow of course
but as long as you keep moving forward you will eventually get there.
Be patient, persistent, and keep reminding yourself that this is fun! A journey of
a million miles begins with a single step...
 
#10 ·
A small update ( you asked for it ). This week I have been trying to assess what needs to be done. Some things are obvious. Both of the Silentium sincers are completelty rotten. The good news is that the part numbers can still be read on what remains, but the bad news is that a search on the internet has brought up no hits on these silencers.
I bought an ultra sonic cleaner to clean the carbs. This had limited success. It got the worst of the gummy lacquer off the body of the carbs but the jets are still blocked. That's not a problem as I expected that I would need new jets, and these are easily available.

The big issue is the cylinder head and I had good news with that. I took it to a friend of mine who restores old cars. He assures me that the damage to the cylinder head is repairable. Somehow, when the head broke off the stem of the valve, it put all of its energy into burying itself in the piston. I took a couple of pictures of the damaged piston, but they aren't clear. I'll try again. I think you will be amused.
 
#11 ·
Another update . So far it's all good news. Detlef Burian appears to have all of the parts that I need, but you lot probably already knew that. The only snag is that I can't order from my iPad. For some reason it won't respond when I click on the images, so I have to use a proper PC.
The other good news is that I took the damaged cylinder head to an engineering company yesterday and they are confident that they can fix it. They'll be giving it a lead free conversion too, and honing the bores which look a little sad. No scratches or damage in the barrels, so the whole thing should be straightforward.

I've spent a lot of time getting the carbs cleaned. I think they are ok now, but I'm going to replace all of the jets because I know how important it is for these to be exactly right.


Meanwhile... for your amusement, I am attaching a couple of pictures of the holed piston and its unwelcome guest.

Automotive lighting Wood Gas Drink Circle
Food storage containers Ingredient Mason jar Drinkware Recipe
 
#12 ·
Hi,
With the carbs I find it's important to make sure the needle valve seals correctly. I always polish the seat which is usually not replaceable with a cotton bud in a pistol drill and buy new needles from Burian or Stien Dinse. After assembling them just check the things seal while off the bike by suspending the carbs and plumbing in some petrol. You don't want bore wash to wreck your new rings nor do you want a load of fuel in your oil or on top of your newly painted engine.

With Dellos there is a tiny idle mixture feed in front of the slide, the camber below this can block up with deposits. Make sure it's clear by squirting some carb cleaner up the relevant air feed at the carb inlet with the idle jet blocked off. I've heard of people running a wire up the air feed to clear it.

Selwyn Motocycles in Cambs are the UK specialists. I think Benelli Bauer have silencers still. Selwyn had some good copies made by Armours (I think) years ago

Chris
 
#13 ·
Richard,

Interesting to see the profile of the 654 pistons, they are far less lumpy than the 354/504/750 Sei ones I've worked on.........those have more obvious cut outs for the valves and very raised centres to the piston tops. Yours appear to make up the CR around the perimeter, unusual.

Nice broken valve, I had the misfortune of bending and chipping the edges off 4 in the same way in a 504 sport, but yours is a proper job. Hammered into the piston, Ouch! :clap:
 
#14 ·
Thanks for the feedback. It's good to know that there are people out there who know about the insides of Benellis. So, I have another question for you.
At the engine side of the carburettors , there is a groove which leads to a small hole. As far as I can see this doesn't go anywhere, and I am assuming this is something to do with the manufacturing process. I have other Dellortos but none of them have this hole. Obviously I don't want to fit the carbs back on the engine if they have any blocked holes, so hopefully somebody out there can clarify what's going on here.
 
#15 ·
Not sure as I don't quite know what you are looking at, it sounds like a groove to the pilot circuit outflow, but I will have a look at some various VHB Dellortos I have. In the meantime, if you haven't got a Dellorto manual, have a look through this.....Dellorto Motorcycle Carburetor Tuning Guides
This Ducati website includes details on the VHB Dellortos so very relevant to DeTomaso bikes and if in doubt, clean it out!
I will let you know what I find.
 
#16 ·
Thanks again. I have seen that tuning guide before, but only as a black and white photo-copy. So the illustrations leave a lot to be desired. I didn't realise there was a colour version. This version is much clearer and I think it may explain what is gong on here. The hole must have a 90 degree turn in it so that the tickover screw can affect the fuel flow as it comes out of the float bowl.

Meanwhile, I have got my restored cylinder head back from the engineering shop. I'm pretty pleased with the result. They also did a lead free conversion on the valve seats at the same time.

Font Auto part Metal Monochrome Rectangle
 
#17 ·
No big update, but I just wanted to say that I rode up to Selwyn's in Cambridgeshire today. I met Selwyn and Liz who both clearly know a lot about Benellis. I bought a load more bits but sadly they don't have Silentium silencers. I always thought they would be a bit like chicken's teeth, so I'm not disappointed. They appear to have everything else that I might need for the restoration.
 
#18 ·
Some progress. I am still slowly dimantling the engine, but also spending a lot of time cleaning it as I go along. This engine must have been leaking a lot of oil beofre it died. It is baked on everywhere. I have also been distracted from the task by "issues" with another of my bikes, but that's not a Benelli, so I won't bore you with that story here.

I have finally split the crankcases. There was a little blood, a fair amount of swearing, but no tears. No new damage found inside the engine. The gearbox looks almost new and it is fun to watch the gears moving back and forth as I move the slector round. I have no worries about the state of that.

I found trhe tip off one of the rocker arms. Not the arm itself but the adjuster with the hardened end that acts on the valve. No more than about 2mm long. It was hiding in one of the sludge traps. The only snag is, there are three missing ! Maybe I'll find the other two under the crankshaft, but most likely they were in the sump.

I am just waiting for a special tool from Pete Rimmer so that I can remove the crank. Meanwhile, here's a picture of the shiny gearbox.

Gas Engineering Machine Font Auto part
 
#19 ·
Update and a question

Some progress has been made. I removed the crank and I have managed to completely clean the inside of the crankcase. I didn't find any more bits of metal so I have now started the rebuild.
While I am waiting for new piston rings and circlips I thought it would be good to check out the brake calipers. I knew that I would want to change the seals but when I tried to remove the pistons I found they were all seized. With some effort I managed to remove them, but the chrome surfaces on most of them was corroded, so I have bought new pistons as well as seals for all three calipers.

My question is, does anybody know what torque I should use on the bolts that hold the caliper halves together ? Or is there even a specific torque setting ? Is "good and tight" good enough ?
 
#20 ·
The calipers have a rubber o ring to seal them together I just tightened mine by hand. Don't over do it ,they are aluminium and you could strip a thread!
 
#21 · (Edited)
Here, here, I agree. You can use recommended torque settings for the bolt size if in doubt.
Engineers handbook says MAXIMUM torque for standard (not high tensile) bolts as 12.5 lb ft for an M8 and 24 lb ft for an M10, so go easy!
As said above the threads are in alloy, you only have to compress the seals, so don't go over the top.:)
I hope this helps.
 
#22 ·
Ah yes, of course. I hadn't thought about that. I was thinking about the high pressure that the hydraulic fluid would be under, and I wasn't thinking about the fact that these are steel bolts in aluminium castings. I guess the O ring will be doing the job of keeping the brake fluid in.
Thanks for the advice. That could have ended in tears.
 
#23 ·
Automotive tire Motor vehicle Gas Cylinder Auto part


Hello Folks, and a Happy New Year to you all. As you can see from the photo, I have been making some good progress with the engine. The engine cases are pauinted and back together, and the pistons are back on their con-rods. Since taking the picture, I have also got the barrels back on, but I didn't think that picture looked as good as this one.
Next step ( obviously ) will be the head and timing the camshaft. My only worry is that this thing is now getting pretty heavy. I think it will be an interesting job getting it off the bench and into the frame.

Big thanks have to go to Selwyn for loads of invaluable advice on the assembly. He has saved me a load of time and trouble with tips on the re-assembly.
 
#24 ·
Hi Richard the engine looks good, when I put my 900 SEI engine back in I put pipe lagging from wickes around the frame tubes. I found that if you could get one of the rear engine mounting bolts in you could then put a trolley jack under the sump and gently raise the engine to align the other bolts.
were did you source a new piston from?
 
#25 ·
Pipe lagging to protect the frame tubes sounds like a good plan. I would be sure to do untold damage without something like that. Should be nice and easy too.
The replacement piston is not new. It's a second hand part that I got from Selwyn. I don't know how many 654s were sold in the UK ( I don't think I have ever seen one on the road ) so it's good that both new and second hand parts are still available. I'm told that some parts can't be found. Original Silentium silencers for instance. It would be good to find a pair of those somewhere.
 
#26 ·
It's been a long time since I updated this thread, but I haven't made a lot of progress over the last few months. This is mostly due to me building a new bigger shed in my back garden to house the project. The new shed is 4m by 5m so plenty of room for the bike and benches etc.
I have replaced the old brake lines with new ones from Venhill as I didn't want to trust the old ones. They looked OK but they were old.
With the engine, I thought it would be good idea to check that the valves are all sealing properly before putting the head back on the barrels. I put the head on the bench and poured white spirit into the combustion chambers. Then left it for a few hours to see if it leaked past the valves. Sadly all four chambers were empty when I came back. Most were leaking through the exhaust valves. I have a grinding tool with a small rubber end but it will only grip the valve for a few seconds before coming unstuck. I have never had this problem before but previously I have only worked on big singles or twins. Never on a head with such small valves. Does anybody have a tip that would help me to keep the tool turning the valve without coming unstuck ?

Richard.
 
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