Engine problem

[MGwarrior350]

I just picked up a yfzr a few weeks ago and got some time today to go on a ride. The guy I purchased it from had taken the spark guard out of the exhaust but did not seem to tune it. It seems like there is no back pressure and the bottom end tends to bog down. I was wondering if this was because of tuning? I have an msd on the way so I can tune it but I wanted to make sure that was the problem. Also how much engine noise are these quads supposed to make, I feel like I can hear the valves a lot more then my old yfz like they are tapping. COuld it be the tuning or something else? Also it tends to have a burning smell and stall on deceleration.

[rdstoner]

ya they make alot of noise how many hours are on it? or do you know.

[MGwarrior350]

Not really sure from the way it looks I'd say 10 maybe 20

[MGwarrior350]

I only used it for an hour any idea why I'm hearing a tap

[Ride1Rob]

Do yourself a favor and have your motor checked. Better to be safe than sorry. Your valves could be out of spec.

[ZRider400]

if it starts fine...then your valves probably arent tight. better to hear them then not at all...

these motors are alot noisier than the older yfz... esp when you first take off/ let the clutch out lugging.. keep your oil changed and air filter clean and you will be good to go.