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low compression ndabf225 ho

L

luckyman

Member
Starboard engine will crank but will not start.Checked fuel,spark. Finally did compression test. getting around 50 psi on all 6 cylinders. All 6 spark plugs looked light tan.There were no catastrophic noises ever, just went out one day and it would not start.With all cylinders so low it seems like there is a valve issue common to all 6 cylinders,probably something to do with the timing belt.What I can see of the belt it looks like it's in good shape.How do I check for some kind of misalignment with the crank and cams?While troubleshooting this engine kept starting the port 225.Two days later port engine would not start.Checked fuel ,spark. Compression good,still will not start.
 
As far as the port engine goes, how are your batteries? Did you deplete them while doing all the testing/cranking? If battery voltage falls below 10vdc while cranking, engine is likely not going to fire.

I don't have the info on your 225 compression or timing with me but I will just say that, many times, a guy will get erroneous results if the test isn't done correctly. You say that the test you did on the port engine came out good so you're probably doing it right but, just to review and get this question out of the equation for anyone else reading your post, did you:
verify batteries fully charged?
remove all spark plugs?
disable fuel system?
open throttle plate fully while cranking/testing?
perform a "wet" test? (optional but always yields useful info about cylinder health)

Hopefully, someone with the timing mark alignment and sequencing will chime in soon to help you.
 
You will have to remove the crankcase pulley cover.

With the timing belt cover off.

Align the the cam shaft pulleys' #1 TDC mark with the mark on the top of the engine.

Check the crankcase pulley. On the lower edge of the pulley, there is a little notch. It should align with the timing mark on the top of the engine. With the front of the engine being 12:00, the mark should be somewhere around the 2:00 position.

If you are getting into aligning a timing belt and you are going to do it yourself, be sure to get the Helm manual to take you through the step by step.

Mike
 
The crankshaft notch was about one tooth off with the cams lined up.I took the Timing belt off.I found the crank notch and block mark and got it lined up. When I try to turn the cams there is a lot of resistance at certain points and I'm afraid that I'm going to break something.I think it's the rocker arm going over a cam lobe but I'm not sure.Crankshaft turns freely so I know there is no interference problem.Checked tension before I took the belt off and it seemed good.This happened at when I tried to start the engine and I was idling before this start.Have you ever heard of these engines skipping a tooth?
 
Have never seen that happen, but then again, I do not see a huge amount of 225's at our shop.

The marks may have been ok. I have installed a timing belt a couple of times. Sometimes they do not align perfectly after they are first set up and you rotate the engine a few times.

As I said before, I strongly recommend that you get a helm manual to help you set the timing belt.

Maybe someone else has run into a 225 belt that has jumped timing...and join in.

Mike
 
I'm no 225 mechanic but I'm always interested. Here's a theory;

If your VTEC spool valve is stuck commanded "ON" then the rockers are locked in high lift mode and you may be encountering the resistance of the lost motion springs when you're turning the cams. This might explain the loss of compression for all six cylinders too. If it's stuck in "above 4500" mode and you're only cranking at around 600 or so when trying to check compression, it's just plain out of sync.

I would think that, even if the valve is stuck, it would eventually bleed off and return to low speed configuration. But, like I said, I don't work on these and I don't know how "air tight" the system is. It might hold pressure forever as far as I know. Just an idea.
 
should I keep turning,can I hurt anything?I have a Seloc manual. It says a resistance check on this solenoid valve harness side pin should be 15-18 ohms. I checked and it is 14.8 on this engine and 14.6 on the other engine.If I have the key on I get an alarm on both engines with it unplugged from the harness during the test so it appears that it is not broken.
 
I'm guessing here just as you are. I would NOT recommend that you keep turning against resistance until you know what you are up against. If it were me, I'd back off on the entire valve train and ensure that I had no bent valves or broken return springs or damaged lost motion springs or cam bearings.

As far as your solenoid valve resistance checks, that sounds like they are ok electrically but I was talking about it being mechanically stuck. Spool valves tend to do that, especially if the lube is contaminated. I would only suspect the one with low compression at this point though.

Like I said before, I'm not the best source of info for your 225's. Just thinking out loud. I'm not a big fan of the Seloc manuals either. I would always want a Helm Inc. manual for any Honda I tear into because the Seloc's just don't seem to be very good. I've gotten by with them in the past but I prefer the Helm. So does almost everyone else on this forum.
 
What do you men "back off on the entire valve train" ? If I can turn the crank round and round how could there be any valve interference?
 
There PROBABLY isn't. But, you seem to be fairly concerned about the resistance you're feeling when you turn the cams.

So, there's really only one way to know, absolutely, if anything is damaged or if you will make it worse. You can have bent valves and not have it be because they kissed a piston. Hydro-lock is one reason. Too much fuel or water entering the cylinder can cause this. Distorted valve guides from poor lubrication or hardware like a rocker arm or adjuster off and up under something else. There are many possibilities other than piston to valve clearance.

You're the man on the scene so you'll have to decide. I'm way over here and all I know is that a small mistake with this engine can turn into major $$$

Have you looked under the rocker covers?
 
Do you mean under the valve covers? I had the valve cover off and every thing seemed to be going up and down normally before when I still had the timing belt on and was turning the crank. Now somehow the cams are on TDC on #5 and I've got the crank on TDC #1 and I'm trying to get the cams to TDC on #1.
 
Yes, the term valve covers is synonymous with rocker covers.

Yeah, when you took off the belt and started turning the shafts independently, it got out of time and now you will need to make sure that you line all that up again correctly before doing any more testing or trying to start it. Have you done any engine work before? I just hope that the Seloc manual has enough good information in it to help you get it back in time properly.

The Honda timing marks aren't always "intuitive". Mike (hondadude) explains above, that "with the front of the engine being 12:00 o'clock, the crankshaft pulley mark is at a "2 o'clock" position".

Get it right. Even though you didn't feel any resistance when you were rotating the crank, it doesn't necessarily rule out this being an interference engine. I don't know whether it is or isn't. You don't want to find out the hard way.
 
It is an interference engine.


The resistance when you turn the cams may simply be the pressure exerted by the valve springs. You will feel this unless you increase the clearances for all of the valves.

I will echo Jimmy....if the timing belt gets put on wrong...major $$$.

Once you have the timing belt back into place....check all of the valve clearances.

Then have you buddy do a leakdown test for each of the cylinders. That will let you know where your compression is going.

Mike
 
got the timing all aligned and belt back on ,my mistake was I rotated the crank pulley 3 times after installing the belt instead of 2 and the cams went to # 5,I rotated the crank a little and the cams rotated easier,put the belt back on and everything seemed fine , redid compression test and all still 50/60 psi,can't be rings, all 6 wouldn't go all the way at the same time,removed 1 head, no indications of bent valves,removed head at #1 TDC, 2 intake valves and 2 exhaust valves on another cylinder are in the open position, all other valves are closed,all 3 cylinders bores look great ,no indications of ring damage,thinking valves sticking open,does anybody know what sugar in the gas does to valves,rings, I was using the boat regularly,putting 40/50 gallons in regularly so I don't think there was stale/sour fuel, thinking bad gas from the pump or possibly sabotauge, taking head to marine mechanic tomorrow,I'm not confident enough to dissasemble head/cams to get valves to closed position to do leak test yet.Yes I am an amatuer but was a evinrude test boat driver 26 years ago and rebuilt several 2 stroke powerheads, my first time with rocker arms,cams and valves.
 
What I don't understand is engine ran fine all day offshore,trolling,running in at 4-5000 rpms and then the next weekend the engine starts, runs fine for a little river cruise, I turn it off to have dinner, finish dinner, try to start it and it never starts again, now all of a sudden I have valves not seating correctly in all 6 cylinders ( marine mechanic says valve seats are shot ),it just sounds suspicious,does anybody know the effects of bad gas or sugar or some other kind of contaminant that could cause this?
 
To answer your sugar question; No, sugar dumped in the fuel will more than likely just stay in the tank as it was proved some time ago that sugar doesn't readily dissolve in gasoline. And, if some of the granules got by the in tank strainer, they would just plug up the fuel filter. There's lot's of info on sugar, Coca Cola and other quick revenge myths if you just google them. That's not to say something else put in there didn't cause it. I would never do that to anyone so there are probably things that could cause problems that I'm not aware of.

You may have noticed that hondadude said these engines are interference. So, your first instinct may be correct. Your timing got off and there may have been some contact causing the valves to be pushed down in the seats. That will need to be looked at very carefully to eliminate the possibility of any pistons or cylinders being damaged.

Keep us posted.
 
I removed and dissasembled both heads for valve job.Only symptom is all intake valves faces are rusty. What would cause this? No marks on piston/valves indicating contact,valve seats that I could see are not in good shape.Only about 200 hours on this powerhead.
Hash marks from honing are not evident, Slight rust on top of some cylinder walls.Can I hone with without removing pistons or would that leave too much foreign material?
 
WOW - That is not good at all! Two things come immediately to mind...

1. Those engines were salvaged from a sunk boat. Where did you get them, and how old are they?
2. Motors were layed up for a long period without prep (fogging). Condensation in the cylinders would cause the rust, thus the damage.

What year are those engines?

As for honing out the rust on the cylinder walls without removing the pistons, I really can't help you there. I've never tried that, and would be very, very reluctant to do so. It would be nearly impossible to get all the grit out between the piston top and the first ring.
 
2002 motors,put on a bracket on a 28 ft Bertram in 2002 by previous owner in NPB,Fl., In 2009 both powerheads were replaced by insurance company due some kind of failure.Owner said ethanol and fiberglass tank were to blame. New aluminum tank installed also.I have verified this as I'm taking the stbd engine apart. I see stamps on components that say 09 03 11, which I believe is the european /japanese way of writing dates,year first.I bought boat this spring and put 100 hours and 1 Bahamas trip , on both engines with no problems at all until I started this thread a few weeks ago and all of a sudden the stbd engine won't start and after some troubleshooting I have 50 lbs of compression in all 6 cylinders. It's just too weird.
 
I agree, that is weird all around.

Did you ever get the port engine running?

I think a sudden failure like that is going to require a complete engine tear down to get to the bottom of the problem. The rust on valve faces and piston sleeves indicates that water was getting in there from someplace, and that should not be happening. And, there may also be damage that you have not discovered. If you are convinced these are not slavaged engines and the heads are new as represented, then there was likely an installation problem with those new heads. The worrisome part, is you may develop the same problem with the port engine. It's going to take a real expert to unravel this mystery. Just my take.

PLease let us all know how this progresses. It should be a learning experience all around.
 
removed heads and took to machine shop for valve job. That's complete. Will start reassembly of heads,intake and exhaust manifolds.Working with honda dealer todetermine where water came from.
 
Whenever that happens, the first thing I check is the emergency stop switch and lanyard. Bypass if necessary. Also, check ground wire at the ECU.
 
still investgating water in all 6 cylinders as seen by white corrosion pits inside exhaust manifold,something is getting water into all six cylinders,
 
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