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View Full Version : Ditech spark plug problem - PartOne



explosive
09-10-2003, 04:11 PM
I have sr50 ditech 2001 7000km.
My scooter runs very nice (abt. 90km/h) when I replace spark plug with new one, but after 300-500km I have noticed that something went wrong with spark plug and my scooter start to choke. I have also noticed that something is wrong when I ride underload. Electrodes of my plug are black and that means that plug is to cold for my engine. I try two different NGK plugs. The NGK CPR8E and NGK CPR10EK. There is no difference in speed or acceleration between this two plugs but I think that NGK8E have a little longer life. I really dont know where is the problem but fact is when my scooter choke I simply replace spark plug and then ditech works fine.
Guy who sells NGK plugs told me that I'm not the only one who has this problem with ditech.
1. I tryed different types of gassoiline. Unleaded petrol 95 and 98. The plugs failed.
2. Then I cleaned the injection system and there was water but I think that this shouldn't cause spark plug to fail. After cleaning plugs failed.
3. I'v changed the oil. I was using Castrol TOP 2T now I have Castrol TTS. Both oils are full syntetic. Plugs failed.
Possible reasons why my plugs fail may be:
-poor quality of fuel
-water and dirt in fuel
-oil
-dirty injection system
One of possible reason could be that NGK plugs aren't ok for my ditech engine so I went to the Piaggio and ask them about their Gillera Runner 50 Pure Jet. Mechanic in Piaggio told me that they have also problem with spark plugs in their 50cc injection engine.
They are using Champion RY6sometging(I think) spark plugs. This plug is same as NGK CPR8E so I bought one and put it in my ditech. I will post a message if I'll have a better luck with this Champion plug.
I'm also planning to buy Denso Iridium IU24 spark plug and test it with my ditech but this plug costs twice as regular NGK spark plug so I'm a little carefull becouse it my be that spark plug is not source of problem.
I have to point out that I have friends with ditech engine and they use same gassoline, same oil, NGK regular plugs as I do and they do not have any chooking or sparking problem. Once again I must tell you that my problem is in burned(failed) spark plug but I dont know what may be reason. I'v changed about 15 NGK plugs and I'm sick of doing that. My scooter has only 7000km.
If you have any comments to the above please post replay to this message.
Regards Explosive

Duc995
09-10-2003, 06:28 PM
I personally think that the stock ditech plug is too cold and am going to try a hotter plug. Take a look at this forum...I think you will see a large amount of people having the same problem as you. I know I have! I have had better luck using a non-synthetic oil, and the stock pipe. The scooter still loves to foul plugs at my 3300 ft altitude (thin air) and summer heat (110 F: thin air), and under load...when the rpms drop on hill climbs. It sucks!

explosive
09-11-2003, 03:23 AM
Thanks for your reply Duc995. Yes, it seems that fuel/air mixture isn't ok when I run underload and that may be the reason why my spark become black and my ditech start to choke, but there is another thing. I put out my dirty black plug, clean it with brass brush and put it in again, and there is no help for this plug. It seems that sparks fly anywhere and that causes chooking. Then I simply replace this plug with another one and problem goes away.
It may be that lack of air causes the problem (burning of insulation of spark plug???, becouse the temperature at electrodes become to high due to bad combustion-lacking of air) with spark plugs and this is serius problem, becouse it seems that we can not to do anything just pray to god hooping that Aprilia will fix the problem soonest possible(new program of something else).
Have you ever try Denso iridium plug? It seems that this plug is better quality than NGK and may have longer life but as I told you before it is very expensive(twice as NGK).
Regards Explosive

apriliabigbore
09-11-2003, 09:37 AM
I have tried the platinum series NGK PMR8A sold on te Forum's online store, but it still seems alittle cold. There is a PMR7A, which is a hotter plug, that I want to try...but you have to order 4 at a time. Maybe if I get motivated enough I will buy 4 and try it.

The thing with cleaning a fouled plug is that the carbon and bits of the wire brush that are used to clean apparently still contaminated the plug and can either short it, or make it run less than optimally even though it appears clean.

Demontech
09-11-2003, 09:41 PM
i have posted this many times, if you foul plugs- it is probly a fuel injection problem. i personaly have had a few air injectors fail causing rich condition. have it checked out.

PAUL
09-14-2003, 11:21 AM
i have been driving around with an NGK CPR8E and it is perfect. many people told me that they have problems with their Ditech. I told them to get a different spark plug (NGK CPR8E) and the problem was solved. Ditech needs a special spark plug, and that's why they are so expensive compared to the other ones. A normal spark plug costs around 4 euros, this CPR8E costs around 11 euros.... :confused:

explosive
09-15-2003, 03:33 PM
Yes, the NGK CPR8E is expensive (abt 11eur) but I have no luck with this plug so I'm now driving with Champion plug. My ditech works fine for now. I did with this Champion plug abt. 150km and I will post a replay how much km i would do without chooking probs.
Regards Explosive

un-pro
05-24-2006, 01:06 PM
hello... I am From Estonia, and i`m riding with Gilera Runner 50ccm Pure Jet (2003. year) I have same problem as you. I use NGK CPR8E and i have that same problem as you. It`s big problem, because i can drive only 3-4 weeks, when my NGK CPR8E Fails :( ... i have`nt get any help in Piaggio. That really makes me sad, because my friends are riding like 2-3 years with their spark plug... what you would do? One my opinion was to build a new engine (with carburetter) but it`s not cheap.. What should i do?

Team Norway
05-24-2006, 03:01 PM
My 2001 ditech had the same problem. It went fine with NGK CPR8E, but after a while something went wrong... The scooter died out and would not start. THis happen last year in august.
I checked the plug and is was black as coal. Then I cleaned the plug and got i nice and shiny. Then I started my ditech but after a while (10 minutes) it died out and could not start it again. Checked the plug and it had a thick layer of black shit on it.
I thought it could be my exhaust that was plumbed...

I spoke whit a Aprilia store in Norway and they gave me a easy answer, just buy NGK CR7E, some ditech doesn't run good on NGK CPR8E..

After I changed to NGK CR7E I have not had any problems the last year..

DOn't know if this is the answer to your question.... Hope u understand my english..

Maybe you should try it?

see yah

RobS
05-24-2006, 09:55 PM
I've been suffering from brief (less than 1 sec) power losses over the past ~500 km. I've got ~900 km on my scoot now. I bought a replacement plug today, CR8E, my local bike shops don't have the CPR8E or the CR7E. I'll take a look at the factory plug tomorrow and see if I need to try the new one.

It's been very enlightenting listening to you guys discuss plugs, power loss, injectors. I'm sure their is more to come on this topic.

Piaggio and Aprilia should have their guys monitoring this forum. I'm sure they could learn something.

Iwo
05-30-2006, 09:44 AM
Denso Iridium IU 24 runs great on morini ditech and piaggio pure jet. Here in croatia almost every scoot has problems with spark plugs, we tested NGK and at the end of the test it showed like worst spark plug for injection engines, after 200 km with that plug scoot just starts work irregular, and with that denso it runs great over 2000 km.
OT: what is the power in horsepower/kilowatts of morini ditech 2003.?

Iwo
05-30-2006, 09:47 AM
hello... I am From Estonia, and i`m riding with Gilera Runner 50ccm Pure Jet (2003. year) I have same problem as you. I use NGK CPR8E and i have that same problem as you. It`s big problem, because i can drive only 3-4 weeks, when my NGK CPR8E Fails :( ... i have`nt get any help in Piaggio. That really makes me sad, because my friends are riding like 2-3 years with their spark plug... what you would do? One my opinion was to build a new engine (with carburetter) but it`s not cheap.. What should i do?
You have mallossi conversion kit to make a carb version from your injection 180 it costs. And you have to buy carb also

p700
05-30-2006, 11:34 AM
Denso Iridium IU 24 runs great on morini ditech and piaggio pure jet. Here in croatia almost every scoot has problems with spark plugs, we tested NGK and at the end of the test it showed like worst spark plug for injection engines, after 200 km with that plug scoot just starts work irregular, and with that denso it runs great over 2000 km.
OT: what is the power in horsepower/kilowatts of morini ditech 2003.?

I bought the Denso IU24 but it doesn't reach as far in the combustion chamber as the NGK CPR8E. This worried me a little. Was I worried for no reason?

Speedway
05-30-2006, 02:41 PM
I bought the Denso IU24 but it doesn't reach as far in the combustion chamber as the NGK CPR8E. This worried me a little. Was I worried for no reason?

if the plug is 10mm X 19mm or 18. something long then....
Nevermind....it is nothing you can feel on the engine..thats for sure
if the plug is the right "heat" range then you will fell..more power from stand still,more crips on the trottle...and gab it at .8
i did it on my denso IU27 gab .8 and it is much better than the NGK C9E
and it burn a nice light brown color
and my plugs is used for about 5000km
then the wether change and i change to a hotter plug down to "8" again when cold
when warm then "9"

SilverSurfer
05-31-2006, 09:50 PM
I'm not sure if anyone else is running as hot of a plug as I am, but it is definitely doing the job for me. I was getting rich fouling on the original "7" range plug, and even quicker fouling on some "8" plugs I tried after that (I didn't realize 8 was colder, actually...). I'm using a CR6E, and the engine runs a lot rougher, but I've not had any of the power-loss or fouling I was with the other plugs. After I kill the two plugs I've got now (and I'm hoping that will take a good long time) I will try out a Denso IU20 (if I can use a non-resistor type plug?) and see if that makes any difference for me. Unless I get a cylinder kit before then...

Anyway, if 8 and 10 range is too rich, try a 7. A CR7EK maybe?

AdySr50DiTech
06-07-2007, 05:12 PM
Wow thank's 2 that forum I understand finaly what's happend with my 2001 ditech.
But at my scooter the problem its evem more serious because the NGK CR8E and NGK CR9EK(new plugs) works just 1-5 minutes before the engine stop woking...and the plugs are black.
I'm form Romania and I spend on new piston kitt 200Euro + 7 NGK CR8E 100E + 4 CR9EK 50E and before see this topic I wanted to buy a new ignition unit:))....
Now I will buy CPR8E and CR7E and I hope to work,if it doesn't I will pass to Platinum and Champion....Anyway in my country are more expensive than normaly.
See ya:cheers:

SilverSurfer
06-08-2007, 01:34 AM
If your CR8E and CR9EK are already coming out sooty (black and dusty), try moving to a hotter plug like that NGK 7 or even a 6. And check your reeds. When I changed reeds it improved my plug life substantially.

Primeruss
06-08-2007, 06:12 AM
Change your plug lead too, If the plug isn't getting a full pulse from the coil it won't help. Plug leads do break down over time, especially the caps.

AdySr50DiTech
06-09-2007, 04:03 AM
a picture of those reeds?caps?plug lead?
Sorry but I don't know what that means in my language...
AND 2DAY I have discover: MISSING THE AIR FILTER, that certanly is a big problem but I ask you if this have a "connection" with black plug?
Sorry my poor english!
Thanks!