Engine swap: any advice?

[Aasland]

So the seller sends me four photos of their compression test - about 208-210 psi each.

Is it possible to have good compression and fail the leak-down test?

 

[FJRay]

So the seller sends me four photos of their compression test - about 208-210 psi each.
Is it possible to have good compression and fail the leak-down test?

If it's not on tdc when the leak down is done then it's possible.

 

[Aasland]

So the seller sends me four photos of their compression test - about 208-210 psi each.

Is it possible to have good compression and fail the leak-down test?

If it's not on tdc when the leak down is done then it's possible.

TDC is when the cam lobes point away from each other?

 

[escapefjrtist]

So the seller sends me four photos of their compression test - about 208-210 psi each.

Is it possible to have good compression and fail the leak-down test?

If it's not on tdc when the leak down is done then it's possible.

TDC is when the cam lobes point away from each other?

Yes, close enough w/o measuring.

--G

 

[Aasland]

So the seller sends me four photos of their compression test - about 208-210 psi each.

Is it possible to have good compression and fail the leak-down test?

If it's not on tdc when the leak down is done then it's possible.

TDC is when the cam lobes point away from each other?

Yes, close enough w/o measuring.

--G

Then I did it right. Hm. Either the seller took photos of the compression test on a different engine, or I'm still not doing something right.

I suppose I can't really test the compression without putting it in the frame and hooking up the starter. Or can I ... I've got both a 6.5 amp drill, and an impact hammer ... ??

 

[Aasland]

I pulled the throttle bodies and peeked at the intake valves:

There is a bunch of red buildup on there .... I can smudge it off, so I don't think it is rust, however .. it reminds of this:

That's from a 1983 V45 that sat in the rain for two years.

I know, let's blame ethanol! Fuel residue sitting in a humid Texan climate for a few months ...

Anyway, I wonder if the valve seats are bunged up with that stuff? At the moment I am soaking the (closed) valves on one cylinder in marvel mystery oil, later today I'll spin the crank a few times and try the leak down again.

 

[RadioHowie]

Don't forget, if you DO decide to pull the head, get yourself a 6 point socket for the head bolts.

They have little, tiny 10mm bolt heads on 'em that will round-off in a New York minute when you try to crack them loose, if you're using a 12 point socket.

I'd recommend a hefty impact-style socket...nice and beefy.

And since they are "stretch" type bolts, you'll need to replace them during the re-install.

 

[RaYzerman19]

Typically, you are supposed to do a compression and/or leakdown test on a warm engine. Also, I usually would do both cold and warmed up, but I'd bet you a warm engine will give you better results (hint, it always does). The reason for warm is so that all metal parts have expanded and oil got splashed on where it should go (cylinder walls, etc.). IF on a warm engine, compression is not reasonably uniform between cylinders, one repeats the test after a spoonful or two of oil was put into the spark plug holes. This seals the rings so you then know if it is rings or valves. Leakdown would confirm valves.

I'd also wager the rings are not the problem on a low mileage engine. But, not having the ability at this point to fire the engine up, you're going to get potentially misleading results when cold....... One option is of course to swap out heads from your known good engine, or better yet in my opinion, would be to get the valves redone on the existing head (maybe they just need to be lapped). Now you know your valves are good.

Of course, all easier done while the engine is out. The other option is just to install the engine and get it running and go for a run. This may show all OK, and you might be able to believe the seller's compression test. This engine's been sitting and it might be revived if just run for a while. Highly likely the engine is from a wreck and wasn't taken out due to compression issues, reliability is good on these things.........

If a compression and leakdown after that showed issues, you can take the head off and get the valves done albeit in tighter quarters, and undoing a lot of work you just did (coolant, exhaust, air box, throttle bodies and on and on).

Play with it a little more, perhaps spin it for a minute or two with the starter (spark plugs out). Compression test with the starter, redo your leakdown, etc. without letting it sit, let us know the results.......... decision time then.

 

[Aasland]

Typically, you are supposed to do a compression and/or leakdown test on a warm engine. Also, I usually would do both cold and warmed up, but I'd bet you a warm engine will give you better results (hint, it always does). The reason for warm is so that all metal parts have expanded and oil got splashed on where it should go (cylinder walls, etc.). IF on a warm engine, compression is not reasonably uniform between cylinders, one repeats the test after a spoonful or two of oil was put into the spark plug holes. This seals the rings so you then know if it is rings or valves. Leakdown would confirm valves.

Good point. Also, the lack of any .. and I mean ANY ... carbon in the intake tracts seem to make the case that they do seal well. But I would still like to get that crud off the valves.

I'd also wager the rings are not the problem on a low mileage engine. But, not having the ability at this point to fire the engine up, you're going to get potentially misleading results when cold....... One option is of course to swap out heads from your known good engine, or better yet in my opinion, would be to get the valves redone on the existing head (maybe they just need to be lapped). Now you know your valves are good.

That's the conclusion I reached yesterday too - more so considering that we have 3-4 weeks until weather lets me ride anyway.

Of course, all easier done while the engine is out.

Yep. So I pulled the head last night - took maybe 15 minutes, and placed an order for the new gasket and bolts ($50).

There was a bit of carbon buildup in all the cylinders, but I could still see the crosshatchings. Based on how clean this engine is for being seven years old with 24k on it ... and it's clean in places that are hard to clean ... and the accident occurred in December .. this engine hasn't seen much use at all and probably suffered from sitting around in humid environments (DFW, TX) and running on old gas. The spark plugs were in pretty bad shape, they were probably the original.

Cylinder #4 had a light tan coating to it. Maybe it needed a TBS? Who knows ... after tearing this machine apart, I'm tempted to dig into my 98k mill and see what that looks like too.

 

[RaYzerman19]

All righty then, you're into it now...... remove the cams, buckets and shims (noting what came from where) and take the head to rebuilder shop and have the valves lapped.... they'll have to remove the valves, springs and keepers...... then spin the valves in the seats with some compound. Could clean up any buildups off the stems if need be. When you get the head back and reinstalled, you might not need to reshim the valve clearances, dunno.

Stay out of the old mill for now... distraction. But one day we'd all like to see pictures of a 98k innards........

 

[Aasland]

take the head to rebuilder shop and have the valves lapped....

I'll do this myself - already have (most of) the tools from when I did that my dad's old kz1100.

 

[Aasland]

I got the valves out and on the two cylinders that had severe leakdown issues had a crusty lip of crud buildup. Maybe not affect actual riding, but now that they're out I'll be doing some lapping.

 

[Aasland]

Last time we mucked with the spare engine it failed the leakdown test spectacularly. Here's how it looked:
Cyl 1: 19% leakage, through exhaust valve and engineCyl 2&3: Total loss through intake valvesCyl 4: ~4% leakage, through exhaust valve and engine
I considered sending it back but the seller had photos of ~212 psi compression on each cylinder, and it would have cost me $200 + $150 restocking fees. Screw that.
So I ordered new head bolts and a head gasket and pulled the heads to lap the valves. Which I did. Then I waited a week for the stuff to ship from ronayers.com and then another week as the snow storm to our east kept my stuff grounded in Indiana.
I got the parts yesterday and slapped the head on, and inspected the valves. All but one is in spec. They were all in spec pre-lapping, so clearly getting junk off the valves did them good. I just need one valve shim before buttoning up the mill (valve cover, etc).
Today I managed to get a leakdown test. Already had oil in the cylinders, and here are the results:
Cyl 1: 2%. Yay!Cyl 2: 3%. Yay!Cyl 3: 1%. Yay!Cyl 4: 30%+ Damnit! !#@&@#!#@#*#! Leaks through the exhaust valve.
So I'm very happy about cylinders 1-3. But goddamn that #4 cylinder, which was perfect before. Somehow I managed to screw this one up.
I'm tempted to pull the head and redo the #4 exhaust valves. The only thing stopping me is that I'll need another 10 head bolts @ $2/each (+shipping) and a week to get them. I don't think I'll need a head gasket though, that should be re-useable.

On the other hand, could it be a fluke? Of all the places to leak from, perhaps the exhaust valve isn't so bad. Maybe it won't leak on a warm engine, when things expand they fit together better. I'm tempted to bolt it all together and see. While it's easier to pull the head off again now, it's only an extra hour of work when the bike is put together.

I re-checked the valves and all but one (intake) valve is still in spec, so I'm waiting for a friend to return my spare shims before I do anything else.



At least it's snowing outside. If it was mid July I'd be really pissed. Or if this belgian dubbel I made hadn't turned out good, I'd be pissed too.

 

[Aasland]

Ok I pulled the head to redo the #4 exhaust valve lapping. Buttoned it up, #4 cyl still leaks a bit. Ugh.

For giggles I warmed up the old engine (still in the bike) and measured the leakdown - all the cylinders showed less than 2% leakdown. Not bad for 95k !! Then I let the bike cool a day... measured again .. they are STILL better than 2%.

So ... now I'm thinking ... why am I mucking with trying to get the newer cylinder head lapped, when I've got a perfectly fine cylinder head on the old mill? Pffft. I'll just put the old head on the new block. Then I can play with the other leaky head when I have time. Like next winter.

Oh ... tip #1: Take off the inner dash plastic before putting front wheel in a chock. Easier to take things apart when you can move the forks.

 

[Donal]

Good idea as long as you are absolutely convinced that the leak is from the cylinder head........... If you can hear/feel it coming out of the exhaust then your plan will work.

 

[RossKean]

I bet that that #4 would be OK after running it in for a little while but if the old head is OK, you might as well use it. I guess the only downside is the cost of the gaskets and bolts for the swap (plus your time, of course). At least you aren't paying a high-priced tech to do the work.

 

[Aasland]

Aaaaand we swapped the engines today. We ended up having to list the frame because the jack I was using didn't drop the engine far enough to clear it.

I heeded Wlfman's advice and had the front tire in a chock, and already had the rear wheel and shaft off, so my strong friends hoisted the rear and made room.

One odd thing ... before I pulled the engine I measured the valves on the Old-Known-Good-Head (OKGH), all in spec. With the engine out, I put the head on the new block, installed camshafts etc. and measured the valves again. This time several valves (intake and exhaust) had ZERO clearance.... wtf ... so I pulled the cams and measured the shims. For giggles I installed the cams againt, re-measured and they were fine. I'm at a loss to explain this. Wierd.

 

[maddad]

Having replaced 2nd gear and such on my 2005, it sounds like solution to go from broken bike to fixed bike is like most of our rides from Point A to Point B, (the longest possible way around).

A couple of things that I went through in doing my transmission after bending a shifting fork.
- Rear tire, shaft and such all have to come off.

- Best to rig up something from the ceiling, cloud hook or something.
1st allows you to lower the engine to the ground nice and slow rather than trying to lower on a jack,
2nd, once you've got the engine on the ground, use the same rig to lift the bike up in the air. You don't have clearance to just slide the engine out from a bike on the center stand.

- I separated the throttle bodies from the engine and air box and left them connected to pretty much everything.

- No need for that special tool mentioned above. Never had any special tools at all.

- Most important, it's not a transition split transmission. Once you have the engine out, you can leave the entire top end right down to the main crank in place. That means you don't have to touch journal bearings, pistons, connecting rods, head, etc. Don't even have to remote the stator.
- I was always scared something would spring out and disappear, nothing did. Remove side covers like stator, clutch, etc. They are just covers.
- Flip the engine, pull off the lower cover and again nothing pops out at you. It's just a cover. Lets you have a good look at everything.
- Next cover/middle assembly is a little trickier but really not tricky at all. Have to pull the final drive gears which are amazingly simple. (Remove bolts slide out)

The whole process took about 2 months for me, but it was winter and I took my time. To do it again, I'd say about 20 hours of labour. Cost me $600 in parts and I replaced every gasket, shifting fork, 2 gears, all seals, rubber part of foot rests, a few miscellaneous plastic parts.

I had about 65,000 miles on it, engine had worked excellent except for the shifting problem and I avoid messing with top ends when they are already doing the job well.

Was always impressed with how the FJR was built. After pulling a Hyabusa Engine and then the FJR engine, I'm even more impressed with the quality and longevity built into the FJR.

 

[Aasland]

Was always impressed with how the FJR was built.

I appreciate the rest of your post, but this was the part I wanted to highlight, because I've noticed the same thing. Everything has been engineered good enough to work well, and not made any fancier than it has to be, which reduces reliability and makes it difficult to service (think: Audi).

At this point I've got the engine in, installed the mufflers and rear tires/shaft and left footpeg. Got all the wire connectors hooked up. Still need to do the radiator, throttle bodies, airbox, etc. I figure I will have it together in a week or so, just in time for our spring weather.

 

[maddad]

Best of luck Aasland. It's a proud moment when you start that thing up again. Not many have pulled, fixed internals or rebuilt an FJR engine. It gives you a whole lot more confidence that you can handle a problem on the road.