250ES Refresh hit a wall...

[danbur55]

compression test will help do it dry then add a few drops of oil and see if it increases should be able to rent or borrow tester from a parts store if close by wouldnt hurt to post some pics of things as these guys on here can spot a flea from a hundred yards

I may have to, wasn't really wanting to go there, but I do want this thing to run after I spent this much money on it thus far. I think I may do a bit more testing to see what compression is doing, if I can find a tester.



Yes I'm using timing marks. I say lobes down to try to make sure you guys know I didn't put it on 180 degrees out.

[DohcBikes]

These guys have said it all. Something is wrong. Take it apart. Post pics.

[6speedthumper]

These guys have said it all. Something is wrong. Take it apart. Post pics.

u\

Yup, agreed. Time for surgery.

You could at least do a leak down test before taking it apart. Do that, and you will know what area to look at when you take it apart. Could only be a valve and you may not have to go any further then taking the head off. It's not a must do thing, though.

[Airmapper]

Thanks guys, last weekend I used my thumb as a compression gauge, it is so leaky I couldn't feel any pressure at all, I figured a dial gauge was pointless, so I started in.

Those head bolts were TIGHT! Took my time on those, let them soak, jarred them with the impact, soaked some more, and let them sit. Warmed them up with a pen torch, and got them loose real gentle like with a breaker bar, phew, I was afraid I was going to strip something.

Right now the only thing holding me back is getting the exhaust pipe off, it's bonded pretty good. Letting it soak in penetrating oil till I can work on it again. Suspense is killing me wondering what those valves look like.......

[Jmoozy27]

Oh yeah, been there a couple of time. It's like defusing a bomb. Don't want to make the wrong move.

[Airmapper]

Well gentleman, mystery solved. (See photos) Except the "how" part, I have no clue what happened to it. It ran when I parked it.

Now I need to figure out how to fix it. It almost has to be bent, I can't see it sticking like that, and I can't do much with it under tension.

Could I fix this right with the typical tools you find around the shop, not specialty tools? I normally hate to have anyone fix anything for me, but would it be worth my while to hand this to a shop?

Thanks for all the help guys, this is as far into an ATC as I've been, despite growing up on the things.

[atc007]

Yes, you can fix that easily. It should slide right out. When they are really bent. Sometimes you have to cut the stem with a dremel and smooth it as to not gouge up the guide on the way out. That's not bad. It hit the piston on the way around out of time . Pull your cylinder and measure it. It needs rings for sure,possibly bored. New valve and lapping,,head will be good as new. Now you see why she couldn't run and compression was coming out the intake lol. Good job.

[DohcBikes]

Yes, you can fix that easily. It should slide right out

meh I don't know about that.... it can be stuck rather tight just as easily. Make sure the guide isn't egged or fractured...

[rdonald1979]

X2 on what Dohc said.

[Airmapper]

meh I don't know about that.... it can be stuck rather tight just as easily. Make sure the guide isn't egged or fractured...

It's been a little bit since I was able to work on this, but this evening I managed to just remove the valve. (I don't have a way to compress it, used the method I found in another thread o get it out and inspect.)

It slid out easily. The hole is not egged visibly. But as my luck would have it, there is a tiny fracture on the part that sticks out. Very hard to see, but sure enough it is there.

What is the worst that could happen if I just put the new valve in and go on, I may have to replace the head later if it wears the valve loose? (which is also the fix for a fracture of this nature anyway right?) The fracture is only along the lower edge, maybe 1/4" long, and there is a lot more surface area to guide the shaft. Except for when a big goof (me), gets the timing out and smacks the valve on the piston, there is no lateral pressure on that shaft correct?

[effort=results]

Pics of fracture please. Sounds like valve guide maybe damaged and at that point do not just throw another valve in . You will be right back where your at now.

[Airmapper]

This is as good a view as I can get, fat camera lens and flashlight won't go in there at the same time.

[83ATC185]

new guides are available from Honda, what's 14 dollars when you've done all this work?

[atc007]

I've personally ground away 20 times that much guide porting before. I would do just that. Dremel it down to where there is no crack,smooth,deburr,ride. Just "buying " a new guide doesn't fix this problem. You need it pressed out and back in. Aligned and regrind the seats. Turns into $200 in a hurry. If you get rid of the crack. She will go for another 30. Most will disagree,I will guarantee lol.

[83ATC185]

Dremel it down to where there is no crack,smooth,deburr,ride.

Never heard of anyone doing this, learn something everyday