connecting rod play

[JONSEREDFAN6069]

sorry guy's just wondering what the acceptable connecting rod play is. i took the cylinder off tonite and the C R moves side to side on the crank and the bearing seems to move in the eye of the rod it has minimal movement when i grab the piston and try to tilt it. the manual say's something about axial and radial play but i forgot it at work. any help wood be muchly apreciated. i have to pick up some batteries tomorrow so no pics tonite. sorry.

 

[PES+]

We wait for the pics

There is lots of explaining and suggestions but pics of what you are describing will be the fastest way to get you some good advice

 

[blsnelling]

It is normal to be able to rock the rod from side to side. It is also normal to be able to slide it frome side to side on the crank. However, there should be NO up and down play. In other words, there should be no radial play.

 

[JONSEREDFAN6069]

thanx Brad, i'm good then i got my radial and axial mixed up.

 

[whitedogone]

I went through the same thing a couple of weeks ago. Since it was my first time inside a 2 stroke, I didn't know what was ok and what was not. This is what I learned:
No play up and down (radial)
OK to move side to side on rod
Lean- OK ( I talked to a tech that said something about 5 degrees)
Twist- not so good (It seemed like I had quite a bit but the tech said it was OK)

Clean things up and get it well lit and move the rod over to one side and look at the bearing cage and the ends of each roller very closly. There should be no damage and no chips in the ends of the rollers. Then move rod over and check the other side. I'm by no means a tech, just relaying things I was told. WDO

 

[JONSEREDFAN6069]

i rechecked tonite and it has a slight bit of up and down just a click click is this going to be ok. or do i have to split the case and crank?

 

[whitedogone]

i rechecked tonite and it has a slight bit of up and down just a click click is this going to be ok. or do i have to split the case and crank?

I had someone tell me if you hear a click when you snap it with your finger... that's nota good.

 

[JONSEREDFAN6069]

thinki'll leave it it has no movement just a click like the bearings moving a little. i have a mahle p&c in it and i want to replace the piston, do i have to put a mahle back in it or can i put another 50mm aftermarket piston in it?

 

[Jacob J.]

Check the big end rod bearing cage and make sure that's intact. If the rod bearings are making a clicking sound, they're on the way out and it's likely the crank won't last much longer. A tiny bit of side-to-side movement is ok, but anymore than about 2-3 degrees off center and you're looking at excessive slop. I've noticed that the bearing rollers wear on the ends first, so the side to side movement is the best indicator for me to tell about wear.

You can put any brand piston you want in there, it just depends on how long you want it to last, how much performance you want, and how much you want to spend. Sounds like to me you have bigger problems there than a piston.

 

[JONSEREDFAN6069]

i rechecked the rod and it is fine. thanx to all with the help. i figured why i had it apart i'd try my hand at porting, i ground a little at a time and went very slow. used a couple different stones i had and a small carbide burr. i
dont know how long it'll last but it runs very strong and the compression went from 160 to 185 cold. i removed the base gasket and the squish went from .042 to .022 i measured the gasket and it is very thick, i used permatex
gasket maker 1 thats gasoline compatible. here's some pics of during i accidentally deleted the final product. not as nice as i've seen on here but not bad for my first try. here's the pics.

 

[Dan_IN_MN]

Looks like you did a good job! Nice pics!

I saw in your sig that you're working on a bike saw........

NEED INPUT!! Do you have any pics of the bike saw?

Dan

 

[JONSEREDFAN6069]

i have the motor and the tranny cut off, thats about it so far. i have the plates for the sides and am goint to get back to it hopefully this week. i went
about an eigth more on the inside cleaned the transfers and smoothed the intake port. thanx btw. i'll get som pics of the bikesaw as i progress.

 

[CHEVYTOWN13]

What is the measurement for the bore? That port aka badboy looks wiiiiide!

I can't wait to sheck out yer vid...

 

[JONSEREDFAN6069]

50mm bore in this one. it screems but the plug is a very dark choclate brown.
i'll get the video camero out tomorrow and do some cookies. had a peice of
12" elm on there and it sliced through it like a hot knife through butta. i think this ones stronger than the other 372. it is getting pretty tired, ordered some new rings for it and i'm going to tear this one down again and play some more. lol i think i can get some more outa it yet.

 

[CHEVYTOWN13]

I've learned to do it in stages. See how the saw acts. And then react. It's fun this way too. Knowing there is still room for improvement and an excuse to turn a wrench on a 2 stroke.

 

[Metals406]

VAROOM!

Jug looks good!

 

[JONSEREDFAN6069]

thanx brotha! i am amazed how much of a difference it made for my first attempt. going to do some more on it at a later date. after i get the other 372 up and running again.

 

[JONSEREDFAN6069]

 

[JONSEREDFAN6069]

 

[CHEVYTOWN13]

Tocayo, awesome job! You have that bad boy 4 stroking gnarly.

THE LAST CUT STOLE THE SHOW!