cb350 bogs down around6000 rpm

[jonob]

Hey guys this is my first post on here ..
Just got given a 72 cb350 and have got her all running except whenever the revs reach around 6000 rpm like highway driving it bogs down.. I have cleaned the carbs and replaced o rings and gaskets except the o rings on the 2 removable jets in the float bowl that hold the little seat for the floats.. The o rings are quite worn and i am wondering if replacing these might stop what seems to be overfuelling or am i barking up the wrong tree entirely??
Anyway i am hoping someone can tell me what to try.

Thanks from newzealand.
Jono

 

[AlphaDogChoppers]

Could be starving for fuel. Make sure your petcock is clear and delivering fuel at a good rate.

 

[rockcitycafe]

if your carbs aren't 100% in good shape, you're barking up the wrong tree chasing any other symptom, fix the o rings

 

[jonob]

Cool. Will try model store tomorrow for some small enough o rings.. Petcoxk shoukd be fine as i had to diy make a new rubber seal so now the fuel wont stol flowing even in rhe 'stop ' position haha.. And float biwls were overflowing until i sorted that problem earlier today.. So i definately t
hink its drowning..

 

[Dragonfish]

Soak the o-rings in pbBlaster for about 20 minutes. They will swell and soften up. Don't leave them in too long or they'll get too big! Do not buy hobby store o-rings unless they are nitrile or the gas will eat them. Check this place out for stock replacements.
http://www.z1enterprises.com/ListItems.aspx?keywords=o-ring

 

[iContango]

Definitely replace the o-rings that ensure the carbs are 1000% clean. Check the petcock screen as mentioned. Ensure the timing is set right.