Honda 250 Elite engine compression questions (long

I just got an 85 honda 250 elite and it seems to be severly lacking in engine compression. I'm not a mechanic but I do know a bit about engines and 250 elites (this is my 3rd 250 elite!). I still do not have a repair manual so if anyone has one for sale or knows where I can buy one please email me ASAP don_ny_@hotmail.com

I bought this scooter site/unseen via the internet at a decent price. With 4100 miles it's in very nice cosmetic condition but it doesn't run. I'm not worried about having to tinker on it to get it running. I actually enjoy working on them.

The scooter arrived via fwd air a couple days ago. I picked it up in my truck and then brought it inside my basement to check it out. It had a new battery and when I turned the key on everything electrically related worked ...even the horn! The dashboard clock doesn't work but that's probably a dead watch battery that I can easily replace.

When I set the emergency brake and hit the starter button the engine turned over really quickly and had that "spark plug is missing" sound. I even thought to myself that the previous owner must have taken it out and forgot to put it back in before he put the side panels back on the scooter. I've heard many engines crank over without speark plugs (dads a VW mechanic) so I know the sound. I took all the bodywork off so I could get to the engine easier. I then pulled the carb and fully cleaned it, including the jets. I checked it out and made sure it had gas running through it. I checked the plug and was surprised to see it actually in the head and properly tightened. I took it out and noticed it a good, strong spark. Good to go so far I'm thinking...

Next I try to start it again. I get that same "spark plug is missing" sound. I check the oil and it's full. I took the spark plug back out and placed my thumb over the hole and hit the starter button. This engine is supposed to have between 156 and 212 PSI of compression. I imagined that much compression would have forced my thumb from the hole on the up stroke. It didn't at all. No air seeped by my thumb! When I removed my thumb and hit the starter I could feel blasts of air coming from the hole but the blasts are not powerful enough to pass by my thumb.

This is where I'm stumped. I'm afraid (really afraid!) I may have to take the engine out of the scooter and apart to find the problem. This will be my first time taking an engine out of a 250 elite. I'm hoping for some advice from people on this forum that have came across and solved similar problems. Any ideas or advice guys?

I've done all I can do to this thing. It looks brand, spanking new all shined up. All the cables are lubed. All the lights work etc. etc. It just won't run.

THANKS IN ADVANCE FOR ANY HELP.

PB280001.JPG

Re: Honda 250 Elite engine compression questions (

PS - That's the "before" picture. You should see it now all waxed up and looking brand new!

Re: Honda 250 Elite engine compression questions (

Its a 4 stroke right?, pull the valve cover off and make sure one of the valves isnt stuck open, if not, check around the head gasket for oil spray (a leak), if not, pour some oil in the cylinder ( like a spoonful or two) and replace the plug if this slows down the engine turning with the starter, then it is a compression problem, with only 4100 miles most likely the rings are broken, hope this helps,, Rog

Re: Honda 250 Elite engine compression questions (

Hi there, not to up on scooters, but on a 4 cycle engine, if the oil has gotten really diluted with gas (thinned out) you will allmost have 0 compression. If mine check the valves as mentioned above, drain oil leaving oil plug out and pour a little WD 40 or such in piston hole, see if it just runs thru or seeps thru into drain pan, if runs thru... gets you some pistons/rings, if seeps I would put in a good grade of heavy weight oil and try it... nothing much to loose but your time and some oil... By the way, does this scooter have a timing belt? gear? could be out of time also. Never worked on one yet.. Doug D.

Re: Honda 250 Elite engine compression questions (

Thanks guys, I will change the oil today and find the valve cover to check for an open valve. I could see one of the valves through the carb hole when I had the carb off. It seemed to be working properly.

it is a 4 cycle engine.

Put in new rings.

Reeperette /

Your description just screams bad/broken/missing piston rings.

As far as I understand, no matter how poor your compression from other causes it should have enough to move yer thumb a little.

I suspect some damn fool was workin on it, and perhaps put it back together without the rings, and then wondered why the hell it didn't run.

(I've gotten three mopeds that way.)

So make sure to check this as well.

(new rings wouldn't hurt, anyhow)

-R

maybe

Its a 4 stroke 250cc 80 mph scooter Ree.

It has a camshaft and valves... a much more complicated situation than a 2 stroke.

First... He needs to check valve clearances after getting the piston at TDC on the compression stroke and check valve clearance.

Then go from there... much like Rog described.

Re: maybe

Ok, I think I have it figured out. Check out the picture above and the one in the next post.

I took the valve cover off and pushed down on what I think is the intake valve (nearest the carb intake) and it moved freely but required some effort. I pushed on the other valve (exhaust?) and it wouldn't budge. Upon closer inspection I see about a tablespoon of brightly colored antifreeze around the hole where that stuck valve goes in. The anitfreeze is sitting undisturbed on top of the 1/4 of motor oil that the valves are covered in.

I'm thinking that somehow over time the antifreeze seeped in there and settled right around that valve and caused it to freeze. Gravity would cause the liquid to end up around that valve because of the way the scooter sits.

This scooter has only been driven 1200 miles in the last 7 years! I'm assuming that it sat for many of those years never being started and it caused this to happen.

Now what? Do I tap on the top of that valve with a hammer to free it?

Thanks for the help guys!

PC010002.JPG

Re: maybe

Next pic.

PC010001.JPG

Re: maybe

Ron Brown /

Don,

If you have lead a good christian life, you may get lucky.

First, you may want to wonder how antifreeze got in the engine.

If you can remove the exhaust, you should be able to see the head and stem of the valve. You can apply penetrating oil to the stem from here and on the top of the valve stem. You can tap on it with a brass hammer or a piece of hard wood and a hammer. Be carefull, if you bend the valve you are done for.

If you can get the valve too move, stuff a reasonable strip of lint free cloth through the spark plug hole and get the piston to tdc. Make up some kind of forked lever that will allow you to compress the valve spring and remove the collets. Now you can take off the retainer and spring. Fasten a wire around the valve stem so that id can't fall into the cylinder and back the piston off from the valve. Now you can check that the valve is free in the guide and possibly clean the stem until it is.

Turn the piston back to tdc, eplace the valve spring, retainer and collets and away you go.

Ron

Re: maybe

I am concerned as to how that antifreeze got there but I'm hoping it was from sitting for years and it will "come out of it" with some run time. I have been spraying it with wd-40 from the top. I got it loose and moving up and down. When it seats it feels weird. Instead of a satisfying "thunk" form the entire round seating surface of the valve making contact I get a "tink". I can then pry up on the srping to make it seat a little tiny bit tighter. After I do this "extra seating" with a screw driver it takes a lot more pressure to get the valve to open. I guess this is what's called a "sticky valve"...

The intake feels great. When I push it down it doesn't stick at all and it returns with that perfect feeling and nice "clunk" sound.

Should I keep working it and spraying it with wd40 from the top hoping it'll get better? Or ...should I put it back together and hope it runs?

My Bad

Reeperette /

I didn't see "4 stroke" in there..oops.

-R

My bad

Reeperette /

Oops, didn't see "4 stroke" in there, my bad.

-R

Re: My Bad

No problem. I may end up doing just what you said anyway. I'm still getting no compression even with both vavles opening and closing. WTF!?

Re: maybe

Ron Brown /

Don,

Did you remove the exhaust and look at the valve stem?

Ron

Re: My Bad

Wow, you must really be frustrated with your bike. I used to have a Honda Aero 50 Scooter, great machine, I can only imagine what the Elite 250 Could do. I have no mechanical suggestions for you, but if all fails, a motorcycle shop should be able to figure it out.

-Wisky

Re: My Bad

Wisky, I'm not too frustrated. I'm learning patience in my old age! Haha! I have to get a manual but I'm too broke right now. That's why I don't take it to a repair shop. As soon as I get one I should be all set. I was thinking that someone might have gone through similar issues with their scooter and could tell me exactly what was wrong.

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