Few questions reguarding our bikes

[Aprilia sr50 02]

Just wanted to get your guys opinions on these as I was told by someone about these and wanted to know if they are definitely true or not.

1. If you full throttle a 2 stroke engine for 26 seconds or more, you can do damage to the engine. I have never heard of this before. Anyone know if this is true, if it is, does it also apply to our bikes and the Ditech engine ? I try not to ride full throttle , but sometimes I have to as I ride in 80km/hr zones a bit, and need to keep it full throttle to keep up.

2. Every 70cc engine seizes (big bore kit). The person I was talking to about my bike recommended me not to get a 70 cc kit as he has never seen a big bore kit that hasn't seized before. If this is true, why does it happen more then the standard engine, and has this happened to many of you's on here ?

And there was another one, just can't remember it right now

[Grenadiers]

LMAO!! Well, I've run my engine at WOT for more then 1/2 am hour at a time (and several times I might add!!) and she hasn't had any kind of damage.

And my BBK hasn't seized...

[Aprilia sr50 02]

Grenadiers maybe he is talking about other 2 stroke engines then ? I know the mechanic told my mate and he has a Yamaha Aerox 100 and it's a carb engine.

If it doesn't apply to ours then I'm happy

[Molino]

Y'know just don't abuse it and it'll keep on ticking. I'm sure most of us here in America who use it for commuting have found ourselves ripping at wot for long periods on end. If you do go the bbk route just remember to put everything together right the first time. They're a bit more resilient then your average aftermarket moped kit.. that & being liquid cooled is definitely a plus for a two stroke engine.

[Aprilia sr50 02]

Yeah that's why I am asking Molino because I want to look after it and want it to last as long as it can. That's why I try and get all the information I can from those that know about our bikes .

And what causes a big bore kit to seize ? And for those that own a BBK, have you had it for a while without problems ?

[High-Gain SR50]

How is it running now. I heard Jason removed the 3 degree key before installing the regulator.
You may want to try the key with the regulator now. I mentioned that to Jason in another forum but am not sure if he saw it.

[Aprilia sr50 02]

Yeah it's running really well now Rich. I had some random spark plug in my bike when I had my service done with that 3 degree woodruff key in, and I think that was the reason why it was stalling. Because when I was adjusting the HGT regulator with that other plug (it was an Iridium plug) I could not get it to 105 psi without spluttering and backfiring. But now I have a CPR8e plug in (as I can't get a hold of a ZMR7AP yet) it's idles A LOT better and can turn the psi up to 130 without much improvement. Now I just keep it at 115 psi to be safe .

And how do you know Jason. You got connections hey

[High-Gain SR50]

I saw Jason post this on another forum.... It was the wrong forum to be asking on as they are all carbureted owners and can adjust their ignition.

I just fitted on request for a customer a advance key for a SR 50 Ditech, now the scooter stalls all the time you come to a stop at an intersection. Has anybody had this only after fitting the new Key.?????

_________________ Precision Scooters Kymco Super9 a/c SYM Red Devil 70cc Honda Forza 250 SYM red Devil 172cc Di potenza per i piloti

He never said anything about the plug being the issue.

I don't know Jason personally but respect him for wanting to learn the Ditech where as others would rather throw a carb on it.
As long as he doesn't listen to the pessimistic Waxhead he will be ok. People like that will drag you down.

Just so people dont get the idea i havent work on these engines before, I have been working on Aprilia SR ditech engine now for 7 years with a leading Aprilia dealer and in that time i have rebuilt 48 motors 29 under waranty and seen just about every kind of problem and failure. With complete access to aprilia data and diagnosotics. I have a complete understanding of the operation of the Australian injection system used on this engine and other watercraft engines. My question is only regarding what the advance key does to the idle of this engine as i couldnt see a drastic change to any part of the performance with this mod on a computer controlled advance curve, in the past i have recorded up to 52 degress advance at light throttle at varying revs. There is a lot of advance when needed.

_________________ Precision Scooters Kymco Super9 a/c SYM Red Devil 70cc Honda Forza 250 SYM red Devil 172cc Di potenza per i piloti

[Grenadiers]

Yeah, I had similar issues with the Advance Key and the Iridium based plugs. They would work for maybe 100 kms and then sputtering, stalling and fouling of the plug.

[High-Gain SR50]

And how do you know Jason. You got connections hey

If he calls me direct next time I will hook you up.

[Aprilia sr50 02]

Yeah, I had similar issues with the Advance Key and the Iridium based plugs. They would work for maybe 100 kms and then sputtering, stalling and fouling of the plug.

Mine has been good for about 1500 k's until I put the Woodruff key in, but I can't wait to try the ZMR plug and see how that goes.

I never used to think a spark plug could make so much of a difference until Grenadiers told me

If he calls me direct next time I will hook you up.

And it's funny how you know the only 2 mechanics in Brisbane that I know that do our bikes, and you are on the other side of the world.

[Rosscofat]

I know both of thos questions are not true.

I have run my 2 stroke RC engine 30.5cc and 70cc engine for much much longer then that. without a problem.


my friends 70cc on his BWS has soft seized same with his friends and his other friends.. but they are not injected etc.

[High-Gain SR50]

And it's funny how you know the only 2 mechanics in Brisbane that I know that do our bikes, and you are on the other side of the world.

The world now is only as big as your keyboard... Us DiTech tech's stick together.

[Aprilia sr50 02]

So the carb engines do seize but the ditechs seem to be more reliable from what you guys
Are saying. Maybe the full throttle thing might be true for CARB engines as well but not for our bikes ? As he was telling my mate and they both had carb engines .

If so I'm glad I ended up Buying the aprilia sr50 even though my mates were trying to get me to buy a Yamaha

I know both of thos questions are not true.

I have run my 2 stroke RC engine 30.5cc and 70cc engine for much much longer then that. without a problem.


my friends 70cc on his BWS has soft seized same with his friends and his other friends.. but they are not injected etc.

[Rosscofat]

dunno if it is that.. they can flood that thing with Huge Jets.. and it still does it.

More likely they do not know how to tune the engines or have the know how like we have available at our finger tips on this forum...

When I talk to them about Variators they are like what.. they make diff models?? How will that help? etc etc. the guy I ride with changes his belt about every 1000km saying its warn out.. LOL to many changes