40mm carb jetting

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mizike77
860 GT / GTS
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40mm carb jetting

Post by mizike77 »

My Darmah has 40mm del orttos on it, a 2 into 1 pipe, and high comp .40 over pistons. Any recommendations for jetting for sea level? Currently has 155 mains and 60 pilot front 65 pilot rear. Seems to be a bit lean. Especially the rear cyl....
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BevHevSteve
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Post by BevHevSteve »

Slide #?
Needle #?

Anything done to the heads (Larger valves &/or porting)?

Please advise
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mizike77
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Post by mizike77 »

Slide 60/1 needle k4(?) in the highest position KnN Filters.... Head work, maybe. Im not real sure. I think mild porting.
wdietz186
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Post by wdietz186 »

When my SS was running close to the same setup I think the mains were richer Around 165 or so.The pilots are in the right range though I don't think they need to be diff. f to r. 60 should be sufficent.You may want to double check your manifolds for air leakage just to be sure.If you have the equipment synching the carbs with vacuum gauges makes a big difference in smoothness.
mizike77
860 GT / GTS
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Post by mizike77 »

Im at my witts end. The cyls seem to be running very differently. The rear is very hot, seems lean, while the front seems to not be doing much. The front plug looks very clean with only some dark color on one side. The bike does run a bit better off the bottom but once the revs pass 5k or so it breaks up terribly. It now has 65 pilots and 160 mains.
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Post by MartinMille BANNED »

Are you sure you are looking for the correct cause to your problem?
Back to basics
• Make sure that the carby manifold spacer is sealing , if you have not replaced them , do so
• Take a look at Steve carby page and get your basic carby set-up correct http://www.bevelheaven.com/~BB/phpBB2/v ... c.php?t=10
• How old are the plugs, if you cant remember replace them
• Swap coils and igniter boxes from front to rear and see if you still have the rear cyl getting hot
• If all checks out fine you may want to remove your side cover and check that the wiring from pick-up coils does not have heat cracks in the wire insulation causing the wires to short out making that cyl go to full advance

I think this should keep you occupied for a little while
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BevHevSteve
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Post by BevHevSteve »

i'd put my money on ignition pickup wires needing to be replaced. Lucky for you I stock the good stuff you need.

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mizike77
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Post by mizike77 »

Intake gaskets are new. Spark plugs are new. Inducer harness is new. Swapped the inducer plugs from side to side with no noticeble difference.Ignition pickups are non stock i think.
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Post by MartinMille BANNED »

Mike what makes you think that they are not gen pick-ups ?
Does the base mounting plate look like it has been re-drilled to suit the new pick-ups?

See if you can borrow someones side cover to see if the problem goes away
if so you know what to do
mizike77
860 GT / GTS
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Post by mizike77 »

The reason I think the pick ups have bee replaced is because the wiring coming out of the cover is non stock and was spliced in with butt connectors up under the tank when i got the bike. I suppose it is possible that only the wire is non stock, having been replaced at some point. I am not too sure what the pick ups are supposed to look like, having never seen another. Also as far as swapping with another cover, well...I have never seen another Darmah in person. There just arent any around here. I dont know af any other sguare case bevels for miles. My step father has since picked up a 75 860gt . He took the Darmah for a ride and decided he needed a money pit of his own. Although I dont beleive that bike has the same ignition. Here is a photo of the inside of my cover, maybe you can tell me if it looks stock or not.
http://picasaweb.google.com/mizike77/Da ... 8289403170
If you hit the arrow at the top of the photo to go one photo back, you will see the wires I am speaking of. They are not the stock colors leading me to believe something has been replaced.
Lumpy
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Ignish

Post by Lumpy »

The pick-up wires on my 82 SS went rotten and she did the same thing as you speak of. Back pot got real hot and nasty. Putting a muti-meter across the the wires gave nothing away, swapping the Bosch boxes did nothing. In desperation i made a timing indicator and it turned out the back pot was not advancing. Spliced in new wires and hey-ho away we go. Point I`m trying to make is it was not that easy to pick. For the sake of some new wire from Steve-o go the hack and change it out. It`s not that hard and it`s good to know it`s done and it`s fresh.
mizike77
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Post by mizike77 »

OK, Just ordered some wire from Steve. At this point I should just sign over my deed to him!! So whats the hot set up for attaching the wire to the pick ups? CanI do it without disturbing the pickup location setting? Im thinking this should be moved to the electrical secton for now ....until I work this out then get back to jetting the carbs.
Lumpy
SD900 Darmah
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Ignish

Post by Lumpy »

No need to disturb the pick-ups. Just take the cover off and pull the wires back through the gland. On my 82 model the wires were inside some sort of rubber moulding. I cut the wires (make careful note of wich wire goes where so you hook it all up the same again) where the insulation seems to change composition. The insulation seems to have a distictly different texture outside the rubber moulding. This leaves you with about 1 - 1 1/2" of wire hanging out the pick-ups. I then slipped over some of that heat shrink with the adhesive inside, soldered on the new wires, slipped the heat shrink over and cooked it. No need to disturb pick-ups. I got all paranoid then and decided that if the ignition wires are like that the alternator side would be much the same. So took that to bits and..........................................right as rain. Would have lasted another 27 years. Replaced it while I was there.
Unfortunatly when all this happened I still thought that Bevelheaven was somewhere I`d go if I changed my oil every 1000 k`s . Had no idea this site existed, as a matter of fact I think my first post here was asking why my beloved SS won`t run like it should. So went through hell and high water to figure it out. Coinsidently I`d left my ignition on overnight, toasted a new battery and cooked the original Nippo Denso coils. Repalced the battery and the coils and she still would`nt run right. Somehow at that precise time my pick up wires turned to pulp, even though she ran like a clock before I left the ignition on. Only a Ducati could do that.
wdietz186
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Post by wdietz186 »

There is the possibility that the wires for one of the pickups have been switched and is running fully advanced on one cylinder.Depending on how much[if any] of the original insulation is left on the wiring coming out of the pickup you might be able to determine the polarity of the pickup.One of the wires has a black stripe on the white wire and the other doesn't.The wiring diagram will show what goes where in respect to the connections at the coil.If the connections are reversed it will run at full advance and also tend to bite you when kicking it.If you can't determine which wire is which a strobe on a timing pointer OR if you have a gear gazer,watching the bevel gear can tell you if it is advancig or not.The proceedure was described in the electrical forum by Lumpy I think.Try looking there for more info. It was a big help when my SD was being bitchy.One other thing that helped on my Darmah was closing up the plug gap to .020".It seems the coils aren't up to jumping much more of a gap.
mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Re: Ignish

Post by mizike77 »

Lumpy wrote:No need to disturb the pick-ups. Just take the cover off and pull the wires back through the gland. On my 82 model the wires were inside some sort of rubber moulding. I cut the wires (make careful note of wich wire goes where so you hook it all up the same again) where the insulation seems to change composition. The insulation seems to have a distictly different texture outside the rubber moulding. This leaves you with about 1 - 1 1/2" of wire hanging out the pick-ups. I then slipped over some of that heat shrink with the adhesive inside, soldered on the new wires, slipped the heat shrink over and cooked it. No need to disturb pick-ups. I got all paranoid then and decided that if the ignition wires are like that the alternator side would be much the same. So took that to bits and..........................................right as rain. Would have lasted another 27 years. Replaced it while I was there.
Unfortunatly when all this happened I still thought that Bevelheaven was somewhere I`d go if I changed my oil every 1000 k`s . Had no idea this site existed, as a matter of fact I think my first post here was asking why my beloved SS won`t run like it should. So went through hell and high water to figure it out. Coinsidently I`d left my ignition on overnight, toasted a new battery and cooked the original Nippo Denso coils. Repalced the battery and the coils and she still would`nt run right. Somehow at that precise time my pick up wires turned to pulp, even though she ran like a clock before I left the ignition on. Only a Ducati could do that.
I have read elsewhere on this site , a post from Steve not recommending splicing into the old wire. Perhaps he can elaborate?
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