Slack in rods bearings?

[jimp1967]

Hey guys,

I bought a '99 Banshee and I have asked questions on tuning here on the site and have got great advice. Now I bought a timing plate to run +4 on the timing and when I removed the the flywheel cover I noticed if you grab the flywheel and rotate it forward and backward there is a slight amount of slack. Does this mean my rod bearings are bad? When I do this I can hear the bearings a little. It's a very slight amount but then again is it suppose to be tight? Thanks for any advice.

 

Jimmy

[bansheesandrider]

That would not be the rod bearings, it would be the crankshaft(main) bearings. Are you wiggling it basc and forth or twisting it back and forth?

[jimp1967]

That would not be the rod bearings, it would be the crankshaft(main) bearings. Are you wiggling it basc and forth or twisting it back and forth?

 

I'm twisting it, If you wiggle it up or down or side to side it's tight. Thanks

 

Jimmy

[papa_smurf49319]

sounds like it may be your woodruff key and or keyway, your trying to turn it over and there is slop between the flywheel and crankshaft right?

[jimp1967]

sounds like it may be your woodruff key and or keyway, your trying to turn it over and there is slop between the flywheel and crankshaft right?

 

No, the flywheel is nice and tight and not moving on the key. It's really not slop I would say but more like a flex I would say. It doesn't move enough to put a measurement to it, well unless I got my dial caliper out. I was just wondering if a slight amount of slack in the rod bearings is ok to run or are the bearings bad.

 

Jimmy

[papa_smurf49319]

i guess i dont know what your saying, if you wiggle up and down on the flywheel its nice and tight, side to side is nice and tight, but if you turn it there is slop? Correct?

 

 

 

Cody

[jimp1967]

i guess i dont know what your saying, if you wiggle up and down on the flywheel its nice and tight, side to side is nice and tight, but if you turn it there is slop? Correct?

 

 

 

Cody

 

If you turn (spin) the flywheel, if you rock it like front back not pulling but twisting like to turn the engine over. If you twist it one direction then another it has a very slight amount of slack. If you just grabbed it and spun it you probably would not notice it, you have to barely twist it to notice it.

 

Jimmy

[jimp1967]

If you turn (spin) the flywheel, if you rock it like front back not pulling but twisting like to turn the engine over. If you twist it one direction then another it has a very slight amount of slack. If you just grabbed it and spun it you probably would not notice it, you have to barely twist it to notice it.

 

Jimmy

 

I talked to a machinist that builds two stroke engines and does machine work for the local Yamaha dealers in Houston and he said nothing to worry about. He said the engine would rattle while running if they were too loose. I just bought it last week and while it was idling I did neel down and listen and it sounded normal. Maybe I'm just looking for something but I just want to be sure it's ok. Thanks for the replys guys.

 

Jimmy

[sleeper06]

They all do that I know exactly what you mean,pressure test it to be sure.Your talking about turnning the crank like a knob back and forth and it clunking so to say

[jimp1967]

They all do that I know exactly what you mean,pressure test it to be sure.Your talking about turnning the crank like a knob back and forth and it clunking so to say

 

That's exactly what I mean, the guy at the machine shop said the same thing you did.

 

Jimmy

[bansheesandrider]

What you are feeling is the piston rocking in the bore when the crankshaft changes direction. All pistons do this to some degree because of the operating clearance, it gets worse as the bore wears and becomes what is known as piston slap. If it is quiet when its running you are OK.