Bog before power band at full throttle

[88yfs]

Okay well I've had this problem forever and I don't understand it, if I go from off idle at full throttle it goes fine then right before it hits the power band it won't go into it, it just keeps cutting out like it doesn't want to go into it, yet if I let off the throttle let's say about 3/4 throttle it will soar right into the band and then I can pin it to win it. I:I It's weird. Also it sometimes hangs onto the revs but not all the time . Like say if it was in neutral and rev it sometimes it hangs onto them and I have to put it in gear to lower it down. Help would be much appreciated.I've gone through a whole top end life and it has never blown or seized so obviously it's not hurting it but I'd still like to fix it.
Also the blaster has a fmf fatty pipe,power core two silencer, k&n filter,no lid on air box.

 

[xKroniK13x]

Jetting! What numbers you running?

 

[Myblasterisblue]

I say jetting as well

 

[Blaaster]

Have you rejetted for the cooler weather, it sounds like you are on the wrong side of the limit of lean.

Have you leak tested it?

You need at least a #290 to #300 main jet with your mods and cool weather.

 

[88yfs]

Wow fast response lol thank you. To be honest it's been so long since I've jetted it. The hanging onto the revs thing? Is that jetting cuz it only does it sometimes like once every like 5 times I stop and rev it. But I'll pull the carb and check jetting I appreciate the fast responses too. It does this in summer and winter so idk about the cool weather thing though.

 

[88yfs]

Also has 120 psi of compression so the piston is good." I would hope so I just redid the top end 18hrs of riding time ago"

 

[Myblasterisblue]

Did you do proper heat cycles and retorque?

 

[DirtDiggler]

Hanging revs is typically a air leak issue , I would say start with a good carb cleaning , new plug and check the reeds . Also check your carb floats , one might be cracked and it's getting fuel In it. If they are good check the float height .
And what intake and exhaust do you have? And what carb are you running and what's your jetting at?

 

[Myblasterisblue]

Read his op. It tells what exhaust and filter

 

[Blaaster]

A poorly adjuusted idle can cause the revs to hang sometimes.

While you are in the carby set the float level, and before you put it back on do a leak test to rule out an air leak.

 

[88yfs]

Thanks guys I'll be checking the jetting very soon and I will also get some new reeds and check the idle. The reeds were fine but there 12yr old reeds so I'm replacing them anyway.

 

[slickerthanyou]

Wow fast response lol thank you. To be honest it's been so long since I've jetted it. The hanging onto the revs thing? Is that jetting cuz it only does it sometimes like once every like 5 times I stop and rev it. But I'll pull the carb and check jetting I appreciate the fast responses too. It does this in summer and winter so idk about the cool weather thing though.

I've gone through a whole top end life and it has never blown or seized so obviously it's not hurting it but I'd still like to fix it.

Sounds like a lean pilot or airscrew setting! Could be an air leak too!

A whole top end life like 66- 68.25?

 

[Myblasterisblue]

I think he means its a stock topend. One that should probably.be tore down and rebuilt

 

[88yfs]

just rebuilt it like 18 hrs of riding time ago still has perfect compression so idk

 

[slickerthanyou]

just rebuilt it like 18 hrs of riding time ago still has perfect compression so idk

Did you try anything else?

 

[Blaaster]

 

[FasterBlaster88]

I Agree With blaster when i use an idle to keep my bike going with a small low end jet it tends to hang onto revs here and there