lack of acceleration

sutty86 · Trackday Trickster Joined: 30 Jan 2015 Karma :

OK I have a derbi Terra 125 yes I know 125 arnt the fastest things but comparing it to my old ybr this thing sucks at setting off.

Just tried servicing it ,fresh oil,air filter,spark plug, couldn't get access to oil filter.
To see if it would fix my problems.

It didn't,
Its dangerously slow setting off like it doesn't start moving until 5000 revs upwards and when I red line it to test it 10000+ it hits 20mph on the speed which in realife is about 15, bump into second ,same again takes hella lot of revs to get moving.

Whilst removing the old spark plug its a pain to get to, the old plug was filthy
https://i.imgur.com/VIHuDQa.jpghttps://i.imgur.com/Z4N5OiP.jpg
https://i.imgur.com/YqIagq6.jpg

Not sure what's happened to cause the white Gunk

On starting the engine I normally have to hold the throttle down to start the engine it starts cold just over 2000rpm then after 2 mins settles around 1700...

Was it could be the clutch slipping , and was told to put it into first and give no revs which it give a tiny little lunge nothing as dramatic as ybr and cut out ...

Air filter is new,but was residue of oil and water which I thoroughly cleaned.
Battery is good motobatt sitting at 12.8v
New spark plug is iridium , no difference to before with normal spark plug...

I did find some metal in oil change like I said I couldn't get the filter out so can't properly investigate https://i.imgur.com/nZvvAzD.jpg

Anyone help, I think the carb is a balls to get out but have put small quantity of FedEx,fresh petrol to try clean it out,allegedly was cleaned out a few weeks back...

iooi · Super Spammer Joined: 14 Jan 2007 Karma :

Possible knackered head gasket. Or the gunk from airbox has been dripping down.

TBH. Get the head stripped off and have a good look at the piston etc.
____________________
Just because my bike was A DIVVY, does not mean i am......

Ariel Badger · Super Spammer Joined: 02 Dec 2006 Karma :

Plug looks as if it has ran weak . What is top picture of?
____________________
Bikers make great organ donors, get 115 on your licence today.

sutty86 · Trackday Trickster Joined: 30 Jan 2015 Karma :

Spark plug socket

iooi · Super Spammer Joined: 14 Jan 2007 Karma :

Was that plug really loose?

As the crap is well down the threads....

Ariel Badger.

Took me a few long looks to work out what it was. A view of the top of the plug....
At 1st I thought it the was working end of the plug with no electrode.....
____________________
Just because my bike was A DIVVY, does not mean i am......

sutty86 · Trackday Trickster Joined: 30 Jan 2015 Karma :

Couldn't really Tell as its really awkward to reach and have a crappy tool

sutty86 · Trackday Trickster Joined: 30 Jan 2015 Karma :

Just put bike on some stand I bought and chain is I think loose,
Just want to run it past you guys first
https://youtu.be/Zbnb3xI3HmA[/url]

sutty86 · Trackday Trickster Joined: 30 Jan 2015 Karma :

No didn't fix it,going to attempt to get carb out later

prawny1 · World Chat Champion Joined: 28 Jun 2005 Karma :

the white gunk could be epoxy, perhaps previous owner stripped the thread in the plug hole?

If the bike isn't knocking or anything I would say the little flake of metal could be just a bit of swarf from a missed judged gear change or something.

It does look like it is running weak though, check for airleaks around the carb and make sure all the settings are correct, checking all the low speed circuits are clean is a good idea whilst you are at it.

Draining the carb down to get rid of any water might be worth a try before all that though.
____________________
hellkat wrote:

Some people are only alive cos its against the law to kill them.