Right side out

[QCBanshee]

I went out riding with a friend mine that has a Raptor 660. I usually ride the dunes in SoCal or out to Ocotillo. I have owned the shee for almost 2 years. It has never failed me until yesterday. We were riding just outside of Green Valley, AZ(3200 ft above sea level). We were on an access road leading to the mountains. We were in 6th gear wide open for about 3-5 minutes(btw, we were dead even). We slowed down when car was approaching in the opposite direction(rolled off the throttle). Once the car passed, I downshifted to 5th and got back on the throttle and lost power. I could not hit the power band at all after that. There was nothing that I could hear that would indicate internal failure. The shee will start on 1-3 kicks, but has no power. I got towed back to our staging area and changed the plugs. That did not work. This is when I noticed that I was down a cylinder(right side). The bike has 20-30 hours on top end that was built at the time I got the bike by Yakkey Racing in Escondido, CA. I've read through the info here and will clean the carbs tomorrow. I do not know what size jets are in the carbs. The bike is stock except for the FMF Fatty's and K&N's on the carbs. It was rejetted when the pipes were added. Is there anything I should look into while I'm cleaning the carbs? If cleaning the carbs doesn't work, I will check compression. Is there a certain way I should check compression(ie warm or cold, # of kicks, brand of tester)? What would be a normal compression reading? I'm new to working on my own bike and any tips, tricks, or specs would be appreciated. Thanks

[snowmanzz13]

sounds like you might have blown a hole in one of the pistons, just the whole running wide open 3-5 minutes, especially if you have the stock petcock on there, one of the bowls could have easily run dry (been there done that also) compression should be somewhere around the 125lbs when you check for a basically stock motor, an thats about al my info lol, someone else will chime in with more info no doubt

[QCBanshee]

sounds like you might have blown a hole in one of the pistons, just the whole running wide open 3-5 minutes, especially if you have the stock petcock on there, one of the bowls could have easily run dry (been there done that also) compression should be somewhere around the 125lbs when you check for a basically stock motor, an thats about al my info lol, someone else will chime in with more info no doubt

 

I haven't torn into it yet and I don't think I will get to it today. This is the second person I've had tell me that I can't run this bike wide open for this long. Is it an issue with the stock petcock? Is this statement true? If it is true, why can't you run wide open for 3-5 minutes? My shee is not a drag shee, it is mostly stock.

[DILUSI]

starts in 1-3 kicks. wouldnt there be some kinda of internal sound going on there or even harder to start if that was the case?

[akita8]

Save yourself some time and do the compression check first. Good thing you has a Raptor there to tow you back. :biggrin:

[magz]

One of the shop owners at my local shop that specialize in banshee says that his main job is fixing banshees were people ran wide open for longer then 5 minutes. said he was going down the road one day driving his car and saw 2 banshees running down the highway next to him said when he was on his way back he saw 1 of the guys pushing the banshee back.

 

as a good rule of thumb i was told never hold down full throttle at max rpm for longer then 30-60 seconds. it just cant take it. and why risk it? its plenty fast enough.

[sled]

any well build 2 stroke should be able to run wide open all day. it sounds like his bike went lean and put a hole in a piston. could of been jetting, could of been the pet cock, he'll have to figure that out. i use to run my RM125 wide open like that all the time. never blew up from that.