ninjette.org - View Single Post - Cleaned Carbs, Replaced Gas, Still having engine problems.

azwillnj · May 3rd, 2012, 05:09 AM

Jet kit came, I installed everything like the kit wanted except I did NOT drill out the slide holes, as stated in the faq.ninja250 (thoughts on this?). Put the needle on position #4 from the top and used DJ098 as the instructions stated for stage 1 with an aftermarket exhaust.

Re-assembled everything and the bike started right up! Even responded perfectly while warm!

BUT.. then I tried to ride it. As soon as you engage a gear and put the engine under load it exhibits similar behavior as before. It's very difficult to get it past 3000 rpm. I managed to crank the throttle open, over rev it to about 6k and slowly let the clutch out to get it moving and tried the 'Italian tuneup'. I got it up to about 50mph (felt great!) while keeping the revs over 5k and revving the piss out of it in each gear. But as soon as I came to a stop it would exhibit the same symptoms. It seems as though it has tons of trouble revving between about 3k and 5k and at this point I think it has to be a jetting/needle tuning thing.

I didn't have a lot of time yesterday so the only other thing I tried was to read the spark plugs and adjust the needle position. I had wiped the right plug down last week when I re-assembled everything so it was fresh before this. When pulled after my ~5min ride they were black indicating a rich condition. I pulled the needles out and moved the stops to #3 from the top (closing the holes more) and it didn't seem to do anything. Today after work I am going to move the stop to position #5 from the top and see what happens.. unless someone has a better suggestion.

What about drilling the slide hole out? It could be bogging at those rpm's because the slides are coming up too fast. The increased size of that hole could fix that. Why is it stated in the faq's to not drill it out?

As for the main jet, It seems to be fine to redline so I don't think I need to change that, but I am not really sure. This is the first time I have tuned a carb and the first time I have ridden this bike/any bike.

Here is the reference on the jet sizes:
http://faq.ninja250.org/wiki/Dynojet...zes_conversion

Alex.

May 3rd, 2012, 05:09 AM	#131
azwillnj ninjette.org member Name: Alex Location: Greencastle Join Date: Mar 2012 Motorcycle(s): 2007 Ninja 250 Posts: 57	Jet kit came, I installed everything like the kit wanted except I did NOT drill out the slide holes, as stated in the faq.ninja250 (thoughts on this?). Put the needle on position #4 from the top and used DJ098 as the instructions stated for stage 1 with an aftermarket exhaust. Re-assembled everything and the bike started right up! Even responded perfectly while warm! BUT.. then I tried to ride it. As soon as you engage a gear and put the engine under load it exhibits similar behavior as before. It's very difficult to get it past 3000 rpm. I managed to crank the throttle open, over rev it to about 6k and slowly let the clutch out to get it moving and tried the 'Italian tuneup'. I got it up to about 50mph (felt great!) while keeping the revs over 5k and revving the piss out of it in each gear. But as soon as I came to a stop it would exhibit the same symptoms. It seems as though it has tons of trouble revving between about 3k and 5k and at this point I think it has to be a jetting/needle tuning thing. I didn't have a lot of time yesterday so the only other thing I tried was to read the spark plugs and adjust the needle position. I had wiped the right plug down last week when I re-assembled everything so it was fresh before this. When pulled after my ~5min ride they were black indicating a rich condition. I pulled the needles out and moved the stops to #3 from the top (closing the holes more) and it didn't seem to do anything. Today after work I am going to move the stop to position #5 from the top and see what happens.. unless someone has a better suggestion. What about drilling the slide hole out? It could be bogging at those rpm's because the slides are coming up too fast. The increased size of that hole could fix that. Why is it stated in the faq's to not drill it out? As for the main jet, It seems to be fine to redline so I don't think I need to change that, but I am not really sure. This is the first time I have tuned a carb and the first time I have ridden this bike/any bike. Here is the reference on the jet sizes: http://faq.ninja250.org/wiki/Dynojet...zes_conversion Alex.