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Have this backpack blower for about 3 years. It was running good, now it started to do this.

Everything works as normal, I can do small jobs with low-mid rpms. But when I set it to max RPM it will start bogging down in couple seconds. If I let off gas and accelerate again it will accelerate and then rpms will dip in couple seconds.

What should I look for?

Model: BBX7600N

common problem on 2 cycles is the screen in the muffler if there is one in the blower take it out an let us know

Thanks Kodie

Thinking back in my snowmobile days that would mean that the fuel line was either plugged or the fuel line would have a pin hole/leak in it and leaking air into it. It just wouldn't get full fuel flow for higher RPM,s. Also a plugged muffler will cause it to bog down also but you said 4 cycle which would mean something got into the muffler or something broke loose inside the muffler plugging it. I know from running 2 cycle mopeds that carbon build up would plug the mufflers and have to heat them to burn the carbon out and I think that what the earlier post was talking about.

Do you suggest taking muffler off completely?

I checked screen - pulled it off and it's nice and clean.
I noticed that intake manifold came loose and thought "a-ha!". Tightened, started again, it was working good for about 5 minutes and then started again. It would run almost full RPM and then vary, it may stay running for a while, it may almost stall when I accelerate and hold. But it doesn't run smoothly on top

Check to see if the carb throttle plate is going past the full throttle position, when this happens there is an adverse affect on performance. Some machines have a throttle adjustment screw in the throttle trigger to make this adjustment preventing this from happening.

I took carb apart, cleaned it. Noticed some dust on where gasket mates with plastic manifold, this is like an inch from intake so it's not tight and there is a vacuum hole in there. Made new gasket, put just tiny bit of silicone around that spot on a gasket.

Seems to be working good now!

katit said:

I took carb apart, cleaned it. Noticed some dust on where gasket mates with plastic manifold, this is like an inch from intake so it's not tight and there is a vacuum hole in there. Made new gasket, put just tiny bit of silicone around that spot on a gasket.

Seems to be working good now!

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Glad you figured it out. :thumbsup: