New engine vibrates

Hey all!

Was wondering if you could help me figure something out.
I just installed a new 25hp B&S Professional Series V-Twin on my Snapper Pro S50XT ZT (to replace a blown 27 HP B&S V-Twin).

I have everything bolted down nice and tight, but when I fire it up, it vibrates like crazy (both at idle AND when PTO engaged).

What is something that I can look for to do to smooth out this annoying vibration?
I am afraid to use it just it case something is amiss.

Thank you all in advance!

ARMYtango said:

Hey all!

Was wondering if you could help me figure something out.
I just installed a new 25hp B&S Professional Series V-Twin on my Snapper Pro S50XT ZT (to replace a blown 27 HP B&S V-Twin).

I have everything bolted down nice and tight, but when I fire it up, it vibrates like crazy (both at idle AND when PTO engaged).

What is something that I can look for to do to smooth out this annoying vibration?
I am afraid to use it just it case something is amiss.

Thank you all in advance!

Click to expand...

I would contact B & S and ask for technical support.

While it is running without the pto on look at the shaft and check if it's wobbling.......... If it is then the crank is bent or your PTO is on wrong and that's hard to do..........

does it sound like both cylinders are firing? Regardless if it came from a store or dealer I would be on the phone to them or B&S technical support to see what they wanted to do.

I have a 2008 Scag Tiger Cub 48" deck with Scag collection system.
The original engine was a B&S 26 HP that had some grief at about 500 hours.
I replaced it with a B&S 30 HP Commercial Turf engine and noticed different vibration characterestics while operating the machine. This engine now has 500 hours on it and I will do a valve adjustment on it this fall. Not sure if a valve adjustment will make any difference, but it has made a difference on other engines that I have done valve adjustments on.
As I have carpal tunnel, my hands do get num after a while when operating my Scag for extended periods of time.
The new engine does have a different bore and stroke from the original engine. The flywheel is heavier also.
Just my thoughts.