2004 Recon No Compression

[Lance Workman]

Guys, had a worn smokey recon 250 to the point it it was fouling plugs. Well pulled the jug looked great and believe my culprit was valve seals. They could not even hold the valve in place. So honed the cylinder for good measure and installed new rings while it was apart. Also lapped valves while it was apart due to little corrosion on the intake valve face, went on and did exhuast while it was apart also. Reinstalled everything, adjusted valves, I cant remember how far out they was but they where out a bit. Well long story short it started up, ran great for about 20 minutes and then randomly died while accelerating. Compression is 60 psi at best.... double checked valve lash and it was way out?? Adjusted it, but you can tell its not right. Still no start, and with rockers arms removed still not compression......? Which making believe ring issue? But why is valve lash  all over the place?! Is there an easy way to check cam to crank timing to make sure it hasn't jump time? Thanks!

[Frank Angerano]

Couple of ways to look at this. 

Double check timing straight away. When you reassemble the top end did you set the timing correctly? Ive done it before and found it 180 degrees out BUT I always slowly rotate the the engine without the spark plug in and feel for any hits between the valves and piston. So if you went ahead and cranked it right out of the gate and timing was off then you could have a cracked piston or bent valve.  (worst case) 

So pull the valve cover off and get to TDC compression stroke and look at your timing, also look at your chain tensioner and make sure you put it all back right and that it had not allowed the chain to jump and cause the above possible damage.   

Have you checked your head gaskets and did you use quality gaskets??  Cheap head gaskets go bad real quick especially if there is a slight warp in the head.  

Valves: did you put the valves back where they came from? Each valve if using old valves should go back exactly where they came from.  Valve seals, its possible one has come off?  
 

Pull the spark plug wire off after you have confirmed the timing is right and crank the engine and listen for air leaks. Spray windex on the top end and look for bubbles if you want.  Spray around the head gaskets, loosen the oil fill cap and spray around that as well while cranking. If you get bubbles then there is compression leaking into the crank case. 
 

 

[MarkinAR]

Odd on the valves being loose.  Valve stem seal's only job is to keep oil from running down the stem into the chamber.  They don't hold the valves in place.  So if the valves were sloppy with the head off i'd think the guides were shot and need replacing.  That would also cause compression issues if the valves wiggle on the seat.

[JacobSlabach]

im in agreement with@MarkinAR.  the valves shouldn't wiggle at all with or without the seals.  if that is the case, your head may be shot😥.  dont know it theres a way to fix this?  maybe jb weld?  i say its worth a shot..  but then again, i try stupid stuff like that with my stuff- dont expect it to work lol.  heads arnt cheap tho- thats gonna suck if the head is worn where the valves run through it.

[Frank Angerano]

It all sounds logical and i agree with the valve slop being a possibility, a valve seal coming off will cause the fouled plugs.  As far as compression goes i have a feeling it's a lot worse then valve slop and maybe a bent valve or something along those lines.  

[JacobSlabach]

6 minutes ago, Frank Angerano said:

It all sounds logical and i agree with the valve slop being a possibility, a valve seal coming off will cause the fouled plugs.  As far as compression goes i have a feeling it's a lot worse then valve slop and maybe a bent valve or something along those lines.  

..also very likely.  did your motor ever make any weird noises?  ticking or knocking and the like?

[Lance Workman]

I may have said that wrong, with the valve springs removed and head just sitting on my bench, the valve would slowing fall out. Not loose like the guide is worn, just that the old seals where not tight on the valves. It isn't my atv but when I first started it, it was little noisy, like timing chain slop but quietened with rpms. Is there a way to check cam to crank timing without pulling the front clutch over? I have gut feeling it jumped time just due the fact on TDC on compression stroke my intake valve is close and my exhaust is starting to open. And its not from being way out on lash, I even verified with just push rod. Exhaust valve is definitely trying to open on TDC. Also, like I mentioned it was running great, no smoke, started easy. It just seemed like it bogged a little so wammy hammered it a littler harder and it tried to pickup for just a second but then instantly fell on its face.

This is what I was talking about on the valve seals, normal just seals are where shot. 

[JacobSlabach]

sounds to me you did everything right, but then the motor jumped time on you.  i would definitely check timing and if your chain is stretched you might want to replace it.  also check that your chain tensioner is functioning and keeping the chain snug

[Lance Workman]

Thats what I figured? Anyone have experience pulling the clutch cover? PITA or easier way of checking the cam to crank timing?

[JacobSlabach]

im not familiar with honda.  owned an old 86 model trx 350 but not a quad with a longitudinal motor

[JacobSlabach]

tbh im really not a fan of recons.  have a buddy that has an 08 recon and has had nothing but trouble from day one that he got it.  however, thats just my experience.  i bet theres really great recons out there..  just not a fan personally.  i looked up videos of how to check/set the timing on a recon and cant find any vids online..  also looked up pics of honda recon motors and i believe there is a alan key plug on the left rear side of your crankcase that should view the fly wheel.(on the opposite side of the cover from the oil fill plug)

i realize that pic is from a newer model but i believe its the place on yours

[Lance Workman]

Thanks man! Yea you can get to the timing mark on the flywheel, but I’m gonna have to pull the whole front cover to see the cam and timing chain assembly. I’ll update when I get it pulled.

[JacobSlabach]

aw shoot thats gonna be a pain

[Lance Workman]

Well got home early and went ahead and pulled the clutch cover. Yea it jumped time.... Such an odd time to decide to jump time, right after redoing the upper end. Hoping it didn't get happy and smack a valve, not sure if they are interference or not?

[JacobSlabach]

oof...  tough break.  is that chain screwed?  if it is i would try a new chain and rotate the motor slowly by hand without a spark plug and try and listen for any valve smack...  if it does have a bent valve, you wont be getting compression and youll have to replace those😒

[Frank Angerano]

Wow!! I knew it, jumped.  That chain looks fu****.  I would double check the chain is free of any more kinks like the one you see and if any links are not moving well then replace it.  
Hopefully no damage to the piston or valves!!!!! Its a long shot but hopefully none.  

 

[Lance Workman]

Yea it’s toast, went ahead and ordered new chain and tensioner. Also ordered an oil pump chain, it seemed to have a lot of slack. Figured it wouldn’t be bad idea while I had the clutch pulled off. I do believe the valves are fine!!! I pulled the rocker assembly and put some air to it. I don’t hear any air escaping. So fingers crossed. I couldn’t get my leak down gauges to work.... so couldn’t get real numbers.

Edited March 31, 2020 by Lance Workman

[Frank Angerano]

That sucks but have you found out why this happened?  One would have to hope it was just a locked up chain.  
 

The only way to test the piston, valves etc for compression would be you have to fill that cylinder head with air pressure and see how it holds.  Even if you have to rig an air compressor hose to the fitting from your leak down gauges that goes into the spark plug hole and set it to 90 psi and fill the head up.  

[Lance Workman]

Not sure why it happened, I suppose just stretched chain.

And then got bound and jumped time?

[Frank Angerano]

Maybe but  if the engine was running fine other then smoke and all you did were valve seals im a little stumped by the chain just binding up.   
That only happens when you are 180 out and a collision happens or no oil.   
Its just odd to me.  

[JacobSlabach]

yea i would be concerned too..  things dont just go wrong on any make of motor like that

[Lance Workman]

Well finally got the parts and everything re assembled except for the clutches due to a cracked basket. But turned it over and now have great compression! Side note, these things are an absolute nightmare trying to install the timing chain. Its a good struggle for sure. Thanks for the help guys!

[Frank Angerano]

Nice work @Lance Workman. Glad it all worked out. 
Ride safe ! 

[Lance Workman]

So finally got parts, replaced both chains, tensioner, and tensioner arm. Still curious why the chain bound up. Awaiting a new clutch basket as one finger was cracked.

[Frank Angerano]

Chains go usually when they get hot or stressed out. Good thing you caught it when you did. If that happened with a full load on it i think a different picture would have been painted.   

[Lance Workman]

Yea I was put around the yard right after getting the head honed and new rings. And didn’t make 3 laps around the house.

[Frank Angerano]

It happens!! Some sh** makes no sense but it just happens! 

[Lance Workman]

I suppose. I’ll have new basket hopefully by the end of the week.

[Frank Angerano]

God only knows with the way shipping is going.  I ordered a fore pit for the yard and it was supposed to be here tomorrow.  Saying Wednesday now.  Fml!

[Lance Workman]

Ok so.... finally got it all back together. Started right up. Smoking now?!? And put it in gear and it’s slipping barely pull. WTF this thing is gonna get the best of me. Why you clutches be slipping? I changed absolutely nothing besides a clutch basket. Is there some kind of adjustment? I torqued the springs to 9lb ft as the manual says. Even the smoking has me stumped it smoked none before the chain pulled its little deal, maybe it’ll clear up. But any ideas on the slipping?