Derbi Senda settings

[shaunt6]

Hi,

I have a Derbi Senda 2006 (Derbi engine)

It's not quite running how it should.

When the bike is cold it runs really well but when it warms up the performance is effected.

The bike has been de restricted and runs a 14t front sprocket along with a slip on filter and hebo filter cover. I put a new piston in 2 months ago when I bought it and all looked good in that area.

If you go flat out through the gears and get into 6th it doesnt accelerate. If your in 6th and your are cruising at 40/45mph it picks up abit better but still not great.

It feels like it's holding back. Any ideas???

Just checked and it's running a 65 main jet. Does that sound about right??

Changing the plug and plug cap today and also all the electrical connectors to see if that makes a difference.

Thanks

Shaun

[0l0dom0l0]

65 sounds tiny. What size carb is it?

I remember on my 2007 GPR, I was running like an 85. That was restricted as well with no mods. De-restricted I think from memory I was supposed to run a 108. Then put a cone filter on that and I would say probably 112.

Why did you change the air filter? The standard airbox's are shaped in a special way to improve power. A cone one totally destroys that. I would put the standard filter back on which might help.

Also, go out for a ride, and do a plug chop, because I think your running very lean. If you are the plug will be white. Post a pic of it if you can.

Who de-restricted it? Also how many miles have you done since it was de-restricted? How many miles has the piston done?

Hope that helps.

[shaunt6]

The bike was de restricted when I bought it and the bike had the filter already on it.

Checking carb size now.

Apart from the exhaust is there any other restrictions.

Piston has done about 800 miles. Bore was in great condition.

If you ran a main jet of 108 then mine is tiny !!!

Thanks

[N cee thirty]

go for a quick ride and the take the spark pug out

post a pic up of the plug
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[Avora]

My senda had a PHVA 14 carb, that was derestricted, would pull hard and rev out in top. The main jet was a 73. Hope that helps out...bear in mind that was the early engines, not the ones in the new aprilia's etc.
____________________
Kawasaki AR125 B8 - Getting ready for a summer time soon!

[shaunt6]

carb is phva14 will have to post pic of plug up tomorow as just got back from trying to get a plug cap

[Avora]

Its going to be a case of learning the general carb tuning stuff, its easy once you know you're way around one, and the senda isn't difficult for tuning. If it idles well, leave that jet alone. The only tuning you'll be doing is moving the needle clip position, put it higher to lean off or move the clip down for richer. That wont change the wide open performance though, thats just the main jet. This all presumes you dont have any air leaks and so on. But that main jet sounds far too small.
____________________
Kawasaki AR125 B8 - Getting ready for a summer time soon!

[shaunt6]

putting a bigger jet in tonight anyone know the best size
thanks shaun