View Full Version : My Aprilia SR Ditech betrayed me

08-21-2007, 11:11 AM
I was riding my scooter yesterday. It was running perfectly and ( I was planning to get a new Pipe - Leo Vince ZX) but suddenly the scooter lost power and stopped. After a few attempts it started but after 200 meters it died again. I tried once again but again after a few attempts it started and after a while it died again. Today I changed the spark plug, (CPR8E as the old one was) but the problem is absolutly the same. So it is not the sparg plug.
Have anyone experienced similar problem and what was the reason of it.

My scooter is Ditech 2002 Morini engine.

08-21-2007, 11:15 AM
How old is the bike, when was your last service, is it making any strange noises, what is the charge on your battery?

08-21-2007, 11:16 AM
btw I also checked the battery and its OK. 12,70V when not working and 13,5V when engine works. Air Filter is also OK.

08-21-2007, 11:20 AM
bike is 8000km. I bought it this spring and made 1500km with it. And as I said it was running perfectly, no noises no smell, no smoke, never had stopped or stalled. I am from Bulgaria Sofia and its very hot this summer here.

08-21-2007, 12:59 PM
Here we go again...:( Mine did this last week See the I'm Back link
The old saying that "if the motor has fuel and spark it has to run even if it runs like crap".
The spark part...
1. Pull the plug and connect it to the HT wire and ground the plug against the stand and turn the motor. Is there a spark? Is it bright? If so go to 2.
The fuel part...
2. Are you getting fuel? - and this is where it gets tricky.
A. It could be as simple as a vapor lock in the gas tank- open the cap and see if it sucks air.
B. Could be water in the fuel. Is the fuel new or from a place you do not usually go?
C. When the motor turns does it pop and try to start or is it dead and turning? When you pull the plug and look - is it wet? If you place a flame near the open spark plug hole does it blow out a flame? (the gas will ignite and make a pop! This can usually help when it is flooded but be careful) :devil:
If it is wet leave it a few hours and try it again. Does it pop or try to start then? If it pops try to play with the throttle when turning it over. You can sometimes get it to start.
Let us know how it goes and we can take it from there because after that we go into the injector.

08-21-2007, 02:04 PM
there was plenty of oil in your tank right?

08-21-2007, 02:22 PM
thanks for suggestions. I think spark plug is OK because as I said I have chaged it with a new one and the problem stays the same. The last 3 or 4 times I topped the tank in the same place.
What bothers me most is that when the bike is completly cold it start perfectly and after a minute or two it suddenly stalls and dies, regardless of how meny RPM I hold in that moment. After that it cannot start for several attempts and after it starts it work again for 1 minute or less and dies. while I am tring to start after it dies the bike is actually almost starting ,it is not running dead.

08-21-2007, 03:52 PM
Definitly read the I'm back link. This is just what mine did. I ended up pulling the injector, which sounds hard but is actually pretty simple. See the How to clean and inspect injector. But you don't have to undo the fuel lines or the fuel rail if you don't want to. In the end I undid the 2 bolts holding in the fuel rail and left the fuel lines connected. I pushed the fuel rail out of the way to expose the injector and hit the starter. The injector poped out and I just cleaned and inspected it and put it back in. In all it took about 1/2 hour from start to finish but it had the side covers already off. Check the O-rings because it is important they are there and intact. (you never know what the other owner did) I found this out the hard way. See also my F**k this bike, nothing but problems!!!! link. Again I went through many of the same problems and it was the injector in the end. The reeds are also fairly easy to check on this model if you have a few basic tools. It sounds like a loss of compression or a blocked fuel filter which is in the bowl of the fuelrail. Either way you end up getting real personal with the injector but don't let it scare you. Welcome to owning an old ditech. :crybaby:
but its great when it runs...

08-21-2007, 04:15 PM
directtech - you should include the link to your threads in your post.

08-21-2007, 08:07 PM
Sounds like emultion in the fuel injection system. Do you have a water trap?If not see the water trap thread

08-22-2007, 07:29 AM
I just spent half a day with my scooter. Here is what i have done:

-Dismantle the injector and removed the air injector from the head( it did not pop out when I used the starter, I had to extract it with my hands, it tokk me several minutes but I think it was easy). All the O-rings were there and were in good condition. Cleaned it and returned it in place.
After this the scooter started but after 2-3 minutes it died again. So after this cleaning it was no significant improvement in the condition of the bike.

- I dismantled the air compressor cleaned it with WD-40 and retuned it. So after this procedure there was I think a little improvement maybe. I was able to make several rounds in the yard in our office and it didn't died. Also when left in idle on stand it doesn't dies too. But when I took it for a ride on the street, there was noticeable drop in power and when I gave it more acceleration it stalled and died. When the engine died I also noticed that it stoppped like I was holding the rear brake, so rapidly. Usualy after stopping I was able to start it again without problem

Waiting for new ideas for my problem. Damn I was so optimistic about my scooter after reading articles in this forum. I was sure that I understand ditech-s very well. It appears I do not.......

08-22-2007, 07:51 AM
Did you removed the injector head's bowl to look for sludge??

08-22-2007, 08:48 AM
- When the engine died I also noticed that it stoppped like I was holding the rear brake, so rapidly. Usualy after stopping I was able to start it again without problem

It sounds like something is binding. Check your variator/clutch. Something may have come loose and it only takes a few minutes to remove the cover. I saw this recently on another bike. They came to me saying the back wheel was locking up and it was the clutch that had come loose. Not to mention the crank that was replaced on mine because the variator came loose. Cheap insurance. Does it start now? You didn't mention it.

Did you inspect the compressor line? Is it in good shape and doesn't leak at the clamps?

08-22-2007, 09:44 AM
Scooter is starting almost everytime after it dies. The rear wheel is moving freely and yesterday I have opened the variator cover to see if everything is fine and didn't notices any problems exept that the belt if for replacement( I measured it 16.9mm width). Don't think somethnig is binding inside variator. This rapid stopping is caused I think by the compression in cylinder. I can sence the moment the clutch dissengage then the bike continues freely. I mean the rapid stopping is only to the momment of clutch dissengagement.

I realy begin to doubt the air compressor, although I did not noticed any problems when I dismantled it. I have to measure the pressure in compressed air line.

08-22-2007, 10:42 AM
The original hose size is 7.5mm, 8mm works fine but the clamps MUST be tight on the air lines .No leakage is tolorated by this system.

08-27-2007, 04:39 AM
Just a thought.

It could be a dirty gaz tank. Preventing gaz from flowing properly when on high trottle. Like the dirt in the tank blockes the fuel from getting through the gaz pump. I suggest you poor in some fuel injector cleaner...let it rest in the tank a bit to melt the dirt..say half a hour...then try it again.

My experience with my Di 07 have told me that this type of scooter is very sensitive to dirty fuel.

08-27-2007, 11:23 AM
I tried today to measure the pressure in the compressor line with a presure meter connected to a hose but the scooter didn't even started with this hose. I didn't notices any leaks and all the hose clamps were tight. I will attach pics later.

Current situation is the following: Scooter is starting without any problems, do not dies when idle and low RPM (athough I sence a significant drop of power) but when I give it more throttle it dies.

I was looking yesterday for a service here to look at by bike but they all refused when saw it was a ditech. And friends I talk to said that the local aprilia dealer understands scooters worse than my grandmother.

It is really a bad situation now...

08-27-2007, 12:49 PM
When you said you removed the injector and cleaned it, did you remove the green thing or the blue thing that actually goes into the head?

I asked because you said it was easy to remove. The blue thing was not easy for me to remove at all. Once I did, as I suspected, the head of it was very caked up with carbon. I cleaned it carefully with carburetor cleaner and a Q-Tip (I don't recommend WD-40). This was my problem, and even after I cleaned it, the brand new plug I had put in was fouled. Even though you just changed your plug, pull it out and check it again. As I mentioned in this (http://www.apriliaforum.com/forums/showthread.php?t=117784) thread, I didn't have the emulsification gunk in my fuel lines, but the carbon was clogging the injector head:


(Micah's after 20,000 miles)

08-28-2007, 05:27 AM
Thanks for reply TiminIndy. I removed the entire injector including the air injector. It looked pretty much like this one in the picture. I cleaned it only with fuel didn't use injector cleaners but it looked very clean after that. Regarding the plug the original one was CPR8E but I used CR8E because there was no CPR8E in the shop and I read in this forum that CR8E should do the same.

08-28-2007, 07:42 PM
Did you pull your new plug and look at it?