Help, Stuck at 6000 rpm

[adamcfc]

Hi all, was out riding with my friend last night when we turned a corner and his bike has started playing up. Any ideas or help would be great.

We were coming off a duel carriageway round a tight left hand bend, as he straightened up he felt he was in too high a gear as the bike was bogging and he changed down to 1st, then as he began to accelerate the bike got to 6K rpm and wouldnt go any higher, its spluttering and doing about 5mph.

The bike is a Derbi GPR 50, since hes had it we know its been running rich, but he hasnt bothered to sort it out as it isnt appearing to cause him any immediate problem at the moment.

I have an idea that maybe some crud has found its way into the carburetta and blocked the main jet, would this cause fuel starvation at 6000 rpm? I also read somewhere that a pipe (something to do with an air pipe) coudl have come off the carb?

Many Thanks, Adam

[stinkwheel]

I'd change the plug first.

If it's a 2-stroke and it's been running rich, the plug is probably heavily fouled with carbon.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[adamcfc]

How could it suddenly of stopped working round a corner though?

And il order a new plug

[Snorty]

[adamcfc]

No its not the choke, it happened when he was riding and the choke wasn't on. I'll check the plug in the next day or so, but no one thinks a jet blockage?

[stinkwheel]

Could be but 9 out of 10 carb problems are electrical.

If a 2-stroke is running oddly, the first thing to do is change the plug.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Teflon-Mike]

[adamcfc]

Ok cheers Stinkwheel.

And thanks for your help too Mike, but calm down? I know the first thing to do is to check the plug, and i know the electrode can diagnose many problems ..... BUT

I cant go and 'fucking check the spark plug' becuase its my freinds bike at his house. Im seeing him tomorow, which is why i wish to have a 'checklist' of things to try with it. Rest assured number one will be checking and probably replacing the spark plug.

If that doesnt help then next i will check the air filter, and fuel lines, check no pipes have come off the carb, and finally strip the carb and clean the jets.

Does this sound logical?

Adam

[stinkwheel]

Seems like a plan of action to me.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.