Bad compression

[Nathan 1]

Ok my 2007 Honda rancher 420 has 30lbs of compression I put 2 tbsp of oil in spark plug hole and it went to 60+ does that mean I have bad rings and need new ones it on time and valves are set 

[shadetree 5,543]

1 hour ago, Nathan said:

Ok my 2007 Honda rancher 420 has 30lbs of compression I put 2 tbsp of oil in spark plug hole and it went to 60+ does that mean I have bad rings and need new ones it on time and valves are set 

hard to say nathon ?, if very well could be rings from the test you did ^^ ?, but it also could have a bent valve ?, bad cam chain ?. out of time ?.

[Nathan 1]

It not out of time I took case off and checked that the valves do t seem to be bent and the cam chain is fine check it also I believe it the rings just be safe ima buy the position and gaskets I read somewhere if it don’t change it the valves but it from 30 to 60+ so I strongly believe it the rings but just want make sure before I take it down and replace it I know someone had this happen

[shadetree 5,543]

11 hours ago, Nathan said:

It not out of time I took case off and checked that the valves do t seem to be bent and the cam chain is fine check it also I believe it the rings just be safe ima buy the position and gaskets I read somewhere if it don’t change it the valves but it from 30 to 60+ so I strongly believe it the rings but just want make sure before I take it down and replace it I know someone had this happen

how did you figure the valves were not bent , without removing the head and removing the valves ?. you can't see bent valves without doing this. low compression does NOT just mean worn rings !. please keep this in mind before you go making guess's..lol.

[Nathan 1]

4 hours ago, shadetree said:

how did you figure the valves were not bent , without removing the head and removing the valves ?. you can't see bent valves without doing this. low compression does NOT just mean worn rings !. please keep this in mind before you go making guess's..lol.

I’ve had 2 mechanics look at it they both told me rings need be replaced I’m not trying be smart but I was was just asking for for more opinions from people idk if they are bent I was told they weren’t but they could be wrong ima buy rings and piston see if it fixes it 

[shadetree 5,543]

1 hour ago, Nathan said:

I’ve had 2 mechanics look at it they both told me rings need be replaced I’m not trying be smart but I was was just asking for for more opinions from people idk if they are bent I was told they weren’t but they could be wrong ima buy rings and piston see if it fixes it 

good luck, keep this thread updated on what you find out !.

[jeepwm69 7,232]

On 11/25/2021 at 3:56 PM, Nathan said:

I’ve had 2 mechanics look at it they both told me rings need be replaced I’m not trying be smart but I was was just asking for for more opinions from people idk if they are bent I was told they weren’t but they could be wrong ima buy rings and piston see if it fixes it 

 

You do know you can't simply drop in a new piston and rings, right?  You have to have the cylinder checked, and most likely bored to match the new piston (which means the piston will need to be oversized).

 

 

[Nathan 1]

I reckon the piston and rings are gone glad I order new ones somehow the cylinder is ok just needs little bit of honing and it be fine idk how this happen 

[oldmxrider 71]

Hard for Me to believe, that Your cylinder will only need a bit of honing with the looks of that piston !  Just My opinion !

[Nathan 1]

2 minutes ago, oldmxrider said:

Hard for Me to believe, that Your cylinder will only need a bit of honing with the looks of that piston !  Just My opinion !

I’ll get pick tmr and had cut the piston off because wrist pin is stuck on now got figure out how get it off

[jeepwm69 7,232]

If your wrist pin is stuck it probably was run hot/ overheated/ low oil. 

 

You’ll be lucky if the connecting rod isn’t shot requiring a new or rebuilt crank.

 

And you can’t tell if a cylinder is good by looking at it. A machine shop will have to measure it for out-of-round.

 

 

 

 

[Nathan 1]

Well I got it out it wasn’t as hard as I thought 

[Derf40 132]

Nathan, i know you want opinions, and mine is, this is not going to turn out good...you gotto go into the bottom...PERIOD  just my opinion. derf

[Nathan 1]

2 hours ago, Derf40 said:

Nathan, i know you want opinions, and mine is, this is not going to turn out good...you gotto go into the bottom...PERIOD  just my opinion. derf

I do t see any problem with bottom end the piston rod is fine no up or down movement the new pin slides right in now I know it has an heat problem and I’m going to figure that out and I’m gonna check oil pump if got one if it bad I’ll replace it I’ve sent the cylinder and piston off to near by ship to get honed and match now I am gonna check the bottom end out tmr ima take it apart just to see what it look like inside hope I don’t find anything bad but we will see

[Fishfiles 19,750]

8 hours ago, Nathan said:

Well I got it out it wasn’t as hard as I thought 

Wow  ----- Mr Crankshaft --- Vince ---  OEM no longer available , ask him for the Versha connecting rod 

[jeepwm69 7,232]

9 hours ago, Nathan said:

I do t see any problem with bottom end the piston rod is fine no up or down movement the new pin slides right in now I know it has an heat problem and I’m going to figure that out and I’m gonna check oil pump if got one if it bad I’ll replace it I’ve sent the cylinder and piston off to near by ship to get honed and match now I am gonna check the bottom end out tmr ima take it apart just to see what it look like inside hope I don’t find anything bad but we will see

 

Slide the new wrist pin into the rod until the end of the wrist pin you aren’t holding barely pokes out of the rod. 

 

Try to wiggle it. If you have ANY play at all you need a new rod, and you’ll ruin a new top end if you don’t replace the rod.

 

i learned that lesson the hard way

 

 

 

[AKATV 746]

 I concur with the above

That wrist pin has some pretty good galling on one side of it it, what does the inside bore of the small end of your connecting rod look like?

 

[Nathan 1]

Well got it all back together today we’ll just the heads carb still off so can’t start it I set the valves intake 0.006 and exhaust 0.009 that what I found online but I believe it’s gonna run it went from 30lbs of compression to 150lbs thank you everyone for y’all help I’ll post video of it running when get all together that be tmr 

[Nathan 1]

On 12/10/2021 at 9:45 AM, jeepwm69 said:

 

Slide the new wrist pin into the rod until the end of the wrist pin you aren’t holding barely pokes out of the rod. 

 

Try to wiggle it. If you have ANY play at all you need a new rod, and you’ll ruin a new top end if you don’t replace the rod.

 

i learned that lesson the hard way

 

 

 

There was no up and down movement and little side to side but that’s stock I heard on every Honda my dealer said it was fine so I left it alone and 

 

On 12/10/2021 at 1:13 PM, AKATV said:

 I concur with the above

That wrist pin has some pretty good galling on one side of it it, what does the inside bore of the small end of your connecting rod look like?

 

The small end looked fine the new wrist pin slid in fine no play in it at all.

 

 

[jeepwm69 7,232]

Should be ok then.  Hopefully it will run well and last you.

 

 

[Nathan 1]

1 hour ago, jeepwm69 said:

Should be ok then.  Hopefully it will run well and last you.

 

 

I hope it last I’ve put an ton of work into it over the course of an month 

[Nathan 1]

On 12/14/2021 at 10:42 AM, jeepwm69 said:

Should be ok then.  Hopefully it will run well and last you.

 

 

You know how test oil pump I took my filter out and no oil coming out into there so I have another 420 took the filter out on it and oil is pumping out of it so took front cover off today and idk how test it and if the pump is clogged how do I test it 

[Nathan 1]

And don’t want run the engine with no oil getting to top end it making valves sound loud and they are set 

[Goober 1,555]

Can’t you leave the run switch in OFF and crank it using the electric start?