XP -98 Help me

[Wedin]

If i hold it at 3000rpm it goes clean and if i hold wot then it runs upp to 5000rpm but after 4-5sec it sink to 4000rpm and goes realy bad.

After that i must go down to 3000rpm and do it again or else it runs on 4000rpm and goes realy bad.

Can it be the coil or cdi box? Pleas say what do you think because i dont have a clue.

I have a new reubild engine,coffman exhaust and solas impeller.

[winterstick]

have you done the fuel lines
if you switch it off does it turn over imediatly
could be coils cooling off at 3000 enough to get you back up to 5000
or fuel filters in the carbs blocked
anyway i wouldn't go back until i found the problem

[SURFnTURF]

change plugs but I dont think thats the real problem,Could be alot of issues cracked pulse line to the carby,dirty fuel filters inside carby,fuel lines breaking down internally(tempo grey ones do it) fuel pump, it sounds like its fuel related so I would pull the carbys and go through them with a rebuild kit.

[Wedin]

Now it goes clean but it dont whant to go faster then 5000rpm. The coil whas 12.5ohm so that one is okay.