Engine knock with video

[Gapper]

Hey guys,

I just got my 250r a few weeks ago and I planned on rebuilding the motor for the simple fact that I do not know the history of it(the previous owner said he never replaced anything-motor related- on it and was not sure if the original owner ever did anything to it either) and the last thing I want is for something to fail out in the middle of nowhere, and/or take other things out along with it. This way, at least I'll know what I have.

Reliability of this quad is at the top of my list. Top be honest, it probably won't get ridden very often(not more then a few hours a year), so I figure if I replace everything that could be replaced one time, it should be good for quite a while.

Anyway, here is a short video of, what I think is, a rod bearing knock or counter balancer bearing or something. I've searched and read quite a bit on here about the "normal 250r knock" but this sounds more then normal I think. I'm totally new to the 250r and two-strokes in general so opinions are definitely welcome.

Thanks guys,
-Matt
<iframe width="420" height="315" src="http://www.youtube.com/embed/9FfeDealhuY" frameborder="0" allowfullscreen></iframe

[bullet225ho]

umm....

something doesnt sound right. LOL

Good lookin bike though.

Hope you get her figured out.

[HAYESTRX250R]

Sounds like the normal knock amplified.

[DoonRider]

Originally posted by HAYESTRX250R
Sounds like the normal knock amplified.

that's what I thought too.

[Gapper]

Hope you get her figured out.

Thanks bullet.


Sounds like the normal knock amplified.

that's what I thought too.

It's funny you guys say that because when I played the video on the computer, the first thing I noticed was how loud the knock seemed on video. It isn't as noticeable in person, but it is there.

-Matt

[C-LEIGH RACING]

Man!!! that pistons got some rattle.

Things that make that noise
Worn piston, piston rocking in the bore.
Worn bearings, on the crank, counter balancer & clutch.
Clutch, crank & balancer shaft gears worn & chattering.
Transmission gears worn at teeth & on the inside where they ride on the shafts & chattering.

Your noise is high in the top part of the engine & sounds just like piston rattle.

Best rebuild it & not ride it any untill you do.

If you take a long wood handle screwdriver or even a dowel rod, place the point in several different places on the engine while it is running & then put the handle to your ear, you can tell where the loudest noise it coming from, can tell just about what it is making the noise.
Neil

[Gapper]

Neil, thanks so much for the info!

The quad is parked for sure. I planned on tearing it apart over the winter and doing as much of the work myself that I can, at the very least, to get familiar with how things work. I've also been searching/reading on here like mad in an effort to know my way around pulling/installing bearings, seals, etc. Troublesome bolts, tips, tricks, tools, all that stuff.

I have the Honda shop manual, but for a newbie like me, it helps hearing peoples' experiences first hand.

I may fire it up one more time to listen a bit closer like you mentioned, just for curiousity sake. We used the long screwdriver trick often at the Subaru garage I worked at years ago.

Winter is fast approaching in central PA, so I am in no hurry with this.

Thanks again for the replies!

-Matt

[Gapper]

Neil, you were right on the money. I grabbed the long screwdriver and listened around on different spots of the motor. Listened to the cylinder and bingo. Very apparent.

I plan on doing the whole motor over anyways but at least I learned a little bit about "piston slap".

Thanks again!

-Matt

[C-LEIGH RACING]

Originally posted by Gapper
Neil, you were right on the money. I grabbed the long screwdriver and listened around on different spots of the motor. Listened to the cylinder and bingo. Very apparent.

I plan on doing the whole motor over anyways but at least I learned a little bit about "piston slap".

Thanks again!

-Matt

Well, I dont claim to be nothing, but I got my learnings, from hanging around some county shops with O L D grease monkeys that could listen to something run & tell you what was wrong with it. They never told or said much, but I aint forgot nothing I seen them do or touch.

It has help as well, to have grown up where Nascar was born at & when they turn my toes up, I'll have grease under my fingernails & still love them ol 2 strokes.

I really believe its my mommas fault though, she loved racing & must have took baths in Unocal 76 racing gas & it ended up marking me.
Neil

[250rice]

wow that is bad. its sounds like bad bearings. my guess is the rod bearing is almost gone. what ever it is you will know it when you see inside the motor because what ever it is its worn really bad.

[timothypantera]

definetly not a normal sound they make it could be a few things i'd pull the stator cover and check for rod slack and bearing play it could be the counter balancer as well. tear it down fix that noise thats a great looking bike worth some dough$$$$

[250R-Dee]

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trying to figure out why this thread isn't showing up correctly.

[jhtrx250r]

I have one that makes a similar noise, not quite sure what it is either?
I think it might be piston slop (excessive clearance) using a steithiscope it sounds like its in the water pump area on mine.
Let me know what you find ?

Thanks james

[C-LEIGH RACING]

When you use the scope, where ever it emits the loudest noise, that is where the knock is coming from.
Piston slap will normally emit the most noise in the head area.

I think over time, lot of hours of service use, the small end of the rod will elongate & we end up with a knock from that. All the pushing & jerking, piston up & down, over time has got to have some affect in that small area.
Neil