Beta Riders Club Discussion Forum

I have a 2017 Xtrainer 300 with 50 hours on it. I have just bought it second hand and it is very well looked after. I haven't had a two stroke in many years and need some advice about engine noise. Everything sounds really good when under load but when you are uptown speed and the engine is just idling along at say 60kmh and not on the pipe it is making this "clack" sound every second or two- almost a metallic sound. is this normal with these engines? Being that it is tuned differently from a normal 2T enduro engine and with my unfamiliarity of 2T engines in the last decade, it is worrying me that it makes this noise? When the bike is under load though it sounds perfect? Any advice would be great. cheers

That to me sounds like it's very likely chain slap, it only takes a little throttle movement to induce that - especially at speed.

^^^ +1

I have about 45 hours on my 2018 Xtrainer. Recently had a weird noise in the middle of a ride. Stopped to check it out and one of my engine bolts was gone and another one had backed out and was about to fall out. The others were loose too. Not sure if this is common but I would check all of your engine bolts to see if they are all tight.

I've heard a similar noise and mine seems like it's in the pipe. I've also heard it on some of the 2 strokes that I rode on a demo day. I installed a JD jetting kit and when I took the bike to 5000 ft the noise seemed to stop. When I returned to sea level and rode a moto x track I could hear it again. There never seems to have this noise under load so I am thinking it may be a needle jetting issue but I'm no great jetting guru. I'm going to try raising the needle up one notch.

Sounds like pinking. Always run super.

Sounds like Pipe Bang. Do a search for two stoke pipe bang and you will find some articles on it. I like the one from PowerCDI. Many discussions about it in other two stroke dirt bike forums as well. Personally, I have it on my 2016 300 RE and I don't do anything about it. It is only shows up after I have been on it for awhile and I cut the throttle and let it motor along at just an idle. Twisting the throttle always cleans it up in short order. It never shows up when you first start the bike and it is warming up. Nor does it show up after the bike has been run, shut off for awhile, and then restarted and allowed to idle. I always equated it to secondary ignition of unburnt fuel near the header, because it probably had glowing hot carbon deposits after getting on it for awhile. But, Fabio (PowerCDI) disagrees with me. I have read some of his other articles, and I always thought he was a knowledgeable individual on the subjects he discusses.

joe

i agree with JoeMaico...pipe bang

Old post I know.... but this is chain slap. The X Trainer suffers badly from it. Adding a bit of rubber under the front chain slider helps and also keep the chain tension correct. My pal has the same bike and I watched the chain slapping away like a guitar string. Annoying but not a big deal.