If I rev up my engine (280) to clean out while stopped it really vibrates. Not the kind of high frequency buzzing vibration I get in my 2T KTMs but lower and it makes the front fender or something up front buzz. Is this normal?

Aren't these engines short stroke large bore? You would think that would reduce rather than increase the tendency to vibrate at high rpm.

check engine bolts are tight failing that it sounds like somethings worn or out of balance ie crankshaft or flywheel ,poss piston slap ?

petrol tank loose or the stay between cylinder base and frame.

I'll check bolts but they all have a yellow marker dot on them implying that someone checked everything at assembly. The bike is new with about 3 hrs on it so unless there was a manufacturing error nothing internally should be out of spec. But that is why I'm asking if they all vibrate like this.

As said before, the petrol tank can buzz a certain revs sometimes.

New gas gas you say?

Check all bolts, strip & grease pivots/linkages.

Do you mean new as in brand new? If so surely it'd still be under warranty?

If new, I know MOST motorcycles come with "pass the emissions testing" jets, which are LEAN jets for a 1000ft elevation? In Kansas at 1000ft, 1st thing I do after I take a bike out of the cardboard, and grease everything is to check the main and pilot, for where I ride! this is easier for me, I have had several years of the "same bike" and can usually just make sure I have the same 2 jets.

The main rattling is usually clutch basket noise, so pull the clutch when you do this (clean out), tell me if the noise changes and goes away? Else it could be like everyone else says, something is loose, usually the Fuel tank will be like "The Who's" concert system (sorry obscure reference to a group that set decibel records back when, at concerts around the world) which highly amplifies sounds. So it might be nothing.

I have had to take the tank loose and see if I need another piece of foam around where it rides in the frame... that or get it to dealer/mechanic have them check it out.

Edited February 4, 201313 yr by sting32

I checked all the bolts I could get to today and except for the fender bolts into the plastic fenders nothing was loose. It's not so much the buzzing noise that bothers me but the fact that the engine vibrates that much. Feels like a CZ from the 70s. Well not really...but still.

The buzz sound could be coming from the front disc guard since it isn't attached at the bottom. ??

Dale and I were going riding this week but he can't make it and he said he was going to be close to my house anywho tomorrow morning so he's stopping by. It will be easier to tell with 2 people there.

It's probably nothing. I just wanted to make sure before I road it much.

Thanks

usually the Fuel tank will be like "The Who's" concert system (sorry obscure reference to a group that set decibel records back when, at concerts around the world) which highly amplifies sounds.

That confirms why my Gasser does the "windmill", It is a fan of classic rock!!!

Dale (US GG distributor) came over and looked at it today. The buzzing sound seems to have gone away after I tightened the finder bolts. He said that the engine vibration is normal and that there was a little pinging going on because I'm running no ethanol pump gas. I guess I need to mix in 1/2 race fuel. He also thought raising the needle 1 step might not be bad either. I'll try the race gas first.

I think we're buying VP's 116 octane (NO ETHANOL) race fuel, then we mix it with NO ETHANOL pump gas, 1 gallon race with 2 gallons PUMP seems to work good.

Dale definitely knows more than I do, but I personally never ran MY bikes with the jets that shipped with it, so I never have heard the ping, unless I rode a friends that had stock jets, plus I have no clue about what gas he had in the bike either.

I got the bike from Lewisport and Adrian jetted it for my elevation before he shipped it.

Someplace around here on one of the billion postits (argh) I have notes from talking to a distrubutor of VP race fuel which is what the KTM shops in town sell. No mention of 116. I think Dale said 1/2 108. I'm building a hot MX bike that is going to need race fuel so I guess I can't put off buying it any longer with 2 bikes that now need it.

The only race fuel that has ethanol is some special blend for National events. I have a place where I buy no eth pump gas. HyVee.

I could be wrong on the octane. I havent had the chore of going 30 miles to get it since I got the new job...

I know it has to be NON ETHANOL. Ethanol and my 2stroke premix oil does NOT mix, and actually gums up the main jet in my Kehins. it did this repeatedly once a month I had to remove carb, clean out a "jelly" blob in the jets. once i quit using pump gas at all (10-15% ethanol and they dont have to tell you it has it in it anymore). I am lucky so far, 1 station that I know the owner, buys NO-Ethanol gas, which right now usually only sells for 2 pennies more, all the time.

My car gets more than 10% better fuel mileage on the same gas.

Edited February 7, 201313 yr by sting32