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Discussion Starter #1
Hello all. First off I want to say that I did do several searches and have read many, many threads on the "no start" problems both on this board and some other Ducati boards, but still have some questions.

I recently just got my '98 916 put back together but can not get it to start. All it will do is crank over ad occasionally backfire through both the exhaust and the intake.

I have tried everything that I can think of, and cannot get the pig to fire up. Upon reading in some other posts, someone made a comment about the cam gears being 360* off. This to me seems virtually impossible, but, this is my first Ducati, so what do I know...

So basically my question is, as long as all the timing marks on all the cam gears are lining up, it has to be in time, right?

I know that I am getting spark, fuel and compression. So what the F is wrong with this damn bike! I have upgraded battery cables (battery to solenoid, solenoid to starter and battery to ground on block), brand new NGK D8EA plugs with brand new TPO MSD 8.5 plug wires. My battery is good plus have a 200amp start function on my charger if need be.

The bike started fine before the teardown and rebuild, it just wouldn't shift right. So new transmission gears and drum, clutch plates and slave cylinder. All new bearings in the cases, but all other internals are stock.

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CLIFFS NOTES
1) transmission broke
2) replaced gears, drum, slave cylinder, clutch, all bearings, plugs and wires
3) now won't start. Just backfires
4) can timing still be off if all marks are lined up?
5) any suggestions?
 

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Discussion Starter #3
Here are some pics of my marks.

Horizontal Intake
ImageUploadedByMotorcycle1335368190.084588.jpg

Horizontal Exhaust
ImageUploadedByMotorcycle1335368256.606777.jpg

Vertical Intake
ImageUploadedByMotorcycle1335368322.770929.jpg

Vertical Exhaust
ImageUploadedByMotorcycle1335368293.622447.jpg

Crankshaft Gear
ImageUploadedByMotorcycle1335368460.233624.jpg
 

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Could be just me, but the front cylinder pulleys are advanced to the marks while the rear is retarded to the marks. Its either at, not both.
You didnt happen to shoot a pic before?

Same belt tension?

I usually turn the engine one tooth over at the driving wheel, and subsequently all marks will be one mark off but upside is vertical intake will stand right on the opening lobe, so you can try that, if it snaps off, timing is no good.
 

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Discussion Starter #6
How about a picture of what's showing through the sight glass on the other side of the engine?
I'll get one when I get home. But I can get it where the notch is lined up and the pulleys look the same.
 

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Discussion Starter #11
It came out wrong, I would never answer in the first place if my intentions were bad ;)
Put the front ones in line with the markings and take a pic of the rear ones.
I figured as much.

I am sorry that I didn't get any pics last night. Was a busy night with the little guy's swim lessons and finally catching up on last weekend's AMA & SBK races.

I will snap some of the requested pics tonight. Promise!

And I KNOW that the marks under the alt cover are correct. I triple checked them after I got done triple checking them.

I'll have to do some reading up on the TPS thing, but would it jut go out of adjustment while sitting on my work bench? I was a little curious about the plug on that though now that you mention it... Does the lead for the TPS come from the wire harness on the bottom side of the throttle body assembly?

Again, thank you all so much for taking the time to try and help me out with this. It is truly appreciated.

Sean
 

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It may be a start relay...these relays tend to go bad after a decade; they are around 25-40$ to replace. There are two relays under the seat and another on the right side just aft of the battery. When these fail, the bike will not start and will backfire when it try's to start. Your cam timing marks look good...hang in there!
 

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The TPS plug has three female pins in it and a spring clip release
to remove the plug from the TPS.
If you have moved either of the two bolts that secure the TPS (plus this is the adjustment to)
it will require resetting, even a tiny bit.


brian.
 

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If you havent actively undone the screws for the TPS it will be fine, it wont move.
If you tear down the bike and it was fine prior and not after, try think about what you fiddled with, lets look at the timing marks, ie pics.

The TPS comes from the same harness as the injectors, you can measure it rather easily, just check timing first and well let you know how to do the TPS, one thing at a time.

Keep calm and do the job and itll sort.
 

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Discussion Starter #15
No, I did not move the screws on the TPS and it seemed to be working fine before hand.

How am I supposed to adjust the front marks any closer? It's not like they are a whole tooth off. Just by belt tension?
 

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No, I did not move the screws on the TPS and it seemed to be working fine before hand.

How am I supposed to adjust the front marks any closer? It's not like they are a whole tooth off. Just by belt tension?
Ok, no they seem on target, just liked to see that ruled out completely.
Someone else asked for if its at TDC, at the markings its TDC at the front cylinder, remove plug and put a screwdriver in and verify TDC while marking is at the driving gear to case.

Boring basic shit, I know, but miss out here and its going to bite you.
 

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You say the plugs and wires are new... That might be an issues - did you check the spark gap before installing? Are you certain that the new wires are correctly seated? Test for spark on both cylinders to be sure.

The reason I say this is because I had the exact same symptoms when I tried installing a set of iridium plugs in my 916. Apparently they didn't agree with the ignition system, it would just turn over and occasionally backfire without starting. Stuck the old plugs back in and it was fine.

For the plugs, the correct ref. is DCPR8 or 9 for the 916. If you are using the D8 you need to make sure the little plug cap bungs are screwed on to for proper seating, otherwise you might be getting a poor contact.
 

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Like this - it should have the crimped round piece on the narrow end, not a bare thread.

 

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Discussion Starter #19
Thank you all for the replies. I'm sorry that I have been MIA, it's been a pretty busy week, plus the weather has been shit here, so no real drive to even think about a broken bike.

But anyway... So I took my belts off and put them back on again just to double check all my marks. I will post pics in my next post. I also pulled my plugs and they are certainly getting spark.

So I would say that my next possible move would be to try and get the new relays that everyone talks about... would you all agree that would be a wise move? It just seems that if I am getting fuel, spark and compression, the damn thing should start, right? Or would one of the relays being bad not allow the injectors to function properly? I know that i can at least hear the pump prime. Is there a way to test the relays to see if they are in fact working properly?
 

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