2006 Rescue - Project Log

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bhendron

Well-known member
Joined
Aug 22, 2013
Messages
133
Reaction score
45
Location
Arizona, USA
I posted recently about an '06 for sale that the PO's mechanic claimed had low compression due to glazed cylinders (post here: https://www.fjrforum.com/forum//index.php/topic/168306-glazed-pistons/). They claimed to have performed a leak down test and determined air getting past the pistons.

The bike has ~50k miles on it and was offered for $1,000. I took the leap and bought it.

IMG_5816_zpsgzahn2en.jpg


IMG_5814_zpsyx3f5uu3.jpg


I have sourced a 'new' motor from an '07 that has 34k on it for $600 shipped. It supposed to arrive no later than the 14th of June.

Meanwhile, I thought I double-check the trouble and see if I come to the same conclusion. It seems to me that a bike of this mileage is due for valve clearance check #2 and that would be the most likely culprit for low compression. The mechanic said all the valves were in spec and even gave me his numbers. With the valve cover all ready off, it was an easy decision to check them myself. I checked, double checked, and triple checked. Here's what I came up with.

My service manual (2002 shop manual) gives spec of Intake 0.15-0.22mm and Exhaust 0.18-0.25mm,

Cylinder 1:

In: .203 .203

Ex: .330 .305

Cylinder 2:

In: .203 .203

Ex: .279 .279

Cylinder 3:

In: .203 .203

Ex: .330 .330

Cylinder 4:

In: .229 .229

Ex: .279 .279

Our numbers don't match and his are a little tighter on some. All of the exhaust are out of spec on the loose side and Cylinder 1 intake out of spec on loose side. Could it be that since the exhaust valves may not have been opening far enough that the gasses were forcing their way past the rings and causing the subsequent pressure issue?

I bought a leak down tester from Harbor Freight however, none of the adapters will fit the plug holes on the FJ. I've ordered a proper adapter.

All thoughts and suggestions welcome! The bike in the shop:

IMG_5818_zps3pnrg4pt.jpg


 
Does it run? Does a compression gauge back up the 'expert' mechanic?

It's interesting that the valves are on the loose side, normally a shim and bucket system gets tight as it wears. Being loose ensures that the valve is closed but it does need to be corrected for all the horses to be released at the upper rpm band. You live in an area where you can let the horses run
smile.png


I think you just won the lottery. The FJR has almost zero cylinder issues but it does often have stuck rings. Yamaha uses a ceramic composite plating on the cylinder walls and it is light years better than iron cylinder liners. You need to get something like Yamaha Ring Free into the cylinders and rotate the engine. If it runs, then add the Ring Free or Sea Foam though the gas. If it doesn't run then pull the plugs, put some Ring Free in the cylinders and rotate the engine in gear using the rear wheel. Give the Ring Free time to work. Rotate the engine some more. The Ring Free works best in a hot engine but will work over time in a cold engine. Ring Free is highly concentrated, read the bottle notes and use accordingly. I'm almost positive that the cylinders are fine.

If it won't start, you could pull the plugs and put a small amount of oil in each cylinder, reinstall the plugs and try to start it. The oil should temporarily seal the cylinders and get it to run.

 
Last edited by a moderator:
..Yamaha uses a ceramic composite plating on the cylinder walls and it is light years better than iron cylinder liners...

so with this ceramic plating is near impossible to wear cylinders due to fuel wash when the bike is flooded?

 
Does it run? Does a compression gauge back up the 'expert' mechanic?
It's interesting that the valves are on the loose side, normally a shim and bucket system gets tight as it wears. Being loose ensures that the valve is closed but it does need to be corrected for all the horses to be released at the upper rpm band. You live in an area where you can let the horses run
smile.png


I think you just won the lottery. The FJR has almost zero cylinder issues but it does often have stuck rings. Yamaha uses a ceramic composite plating on the cylinder walls and it is light years better than iron cylinder liners. You need to get something like Yamaha Ring Free into the cylinders and rotate the engine. If it runs, then add the Ring Free or Sea Foam though the gas. If it doesn't run then pull the plugs, put some Ring Free in the cylinders and rotate the engine in gear using the rear wheel. Give the Ring Free time to work. Rotate the engine some more. The Ring Free works best in a hot engine but will work over time in a cold engine. Ring Free is highly concentrated, read the bottle notes and use accordingly. I'm almost positive that the cylinders are fine.

If it won't start, you could pull the plugs and put a small amount of oil in each cylinder, reinstall the plugs and try to start it. The oil should temporarily seal the cylinders and get it to run.
Thanks so much for this response! Owner claimed hard starting and poor running. He rode it to the shop so 'ran when parked'. I'm heading to the garage to do a compression test right now.

I guess I'm ignorant as to what causes stuck rings and exactly what's going on when that happens.

 
Check compression with all the plugs out and a fully charged battery, cranking speed will affect final readings. On a stone cold engine you may see around 170 - 180 psi if it is running correctly. When you do the compression test you want all the cylinders to be roughly the same. If the readings are in the ball park of 'the same' but all low, add roughly a tablespoon of oil to each cylinder as you test it and try again. If the compression readings go up, it is conclusively the rings or cylinders causing the low readings.

The ceramic composite cylinder liners are almost certainly ok. Worst case would be needing to replace really, really stuck rings.

I ran my Gen I FJR hard (drag strip and WFO street riding) using the correct grade of gas from a name brand gas dealer and the same quality oil changed at proper intervals or sooner, but at ~40k miles I had stuck rings in 3 of 4 cylinders. In fact, my pistons looked like they were covered with red rust -- but aluminum doesn't rust. It looked like the rings had issues with the fuel and not burnt oil getting past the control rings. I found this when my engine was out on the shop floor and the cylinder head off for other reasons. We had pulled the pistons to check for bent conn rods, mashed wrist pins or damaged pistons (yes, yikes!). The FJR's engine was tough, the whole lower rotating assemblies were undamaged, unlike all the crushed valves and split valve guide sleeves. Yes, there is a story and it was played out here on the Forum
smile.png


People can have strange ideas and do weird and strange things to their motorcycles. Who really knows what the original owner as done to this bike. But, don't rule out simply stuck rings because as previously mentioned, it does happen to the FJR. Perhaps that slick ceramic composite cylinder liner doesn't flutter the rings enough to keep them from sticking

 
Last edited by a moderator:
ionbeam, you're my new best friend! After getting the valve cover back on, the coolant pipe reinstalled, PAIR hoses, etc., etc., I did test each cylinder. However, I only had the plug out of the cylinder I was testing. And, the battery was clearly not full charge. What I saw was, cyl 1: ~45psi, cyl 2 ~45psi, cyl 3 ~61psi, cyl 4 52psi. I added some oil to 4 and 1 and tested again and reached into the 90's. They all seemed so incredibly low per the manual that I just left it be for the moment. The battery is on a charger right now and I'll try again tomorrow per your instructions. Thanks so much for your input!

 
If you can get it to start and run, I would try the chemical enemas (Ringfree, Seafoam etc.) as per post #2 before I got too excited about the compression. How long since it was last run?

Do you have the seat, side plastics, windshield etc?

 
Sounds like a project!

As Ion posted above, make sure you have all four plugs out, a charged battery and fully open the throttle [WFO!] for an accurate compression test. After that...Ring-Free chemical treatment would be next on the list.

Good luck!

--G

 
Be wary of drawing too many conclusions about compression on a cold engine. Consistency is what you're looking for, and they may all seem low. Needs a retest on a warmed up engine whenever that can be done.

 
If you can get it to start and run, I would try the chemical enemas (Ringfree, Seafoam etc.) as per post #2 before I got too excited about the compression. How long since it was last run?
Do you have the seat, side plastics, windshield etc?
Yes, seat, plastics, windshield, etc. It even came with this handy bag of hardware!

ff23c5d9-fe50-4e9e-bcac-74d2a69095b5_zpsoz94hp0q.jpg
:

By the way, can any Gen II owner identify what these doo-hickys hold together? Us Gen I folks don't have these (I don't think):

IMG_5820_zpskskknnre.jpg


 
Last edited by a moderator:
Those are the 1/4 turn bolts that hold the movable panels in place. There should be 4 of them. They are the ones you can see just in front of your knees when you look down from the seated position.

Some of these guys know their actual name. I can't remember it.

 
Last edited by a moderator:
I charged the battery overnight and today I got some Ring Free. Before I could put it to use, I had to reconnect the air box. What a PITA. And after that, I pulled all the plugs and re-did the compression test. Results as follows:

Cyl 1: 100 psi

Cyl 2: 90 psi

Cyl 3: 100 psi

Cyl 4: 130 psi (overachiever)

I just made note of it, cleaned ad re-gapped the plugs (all gaps a tad wide), and re-installed them. Then re-mounted the gas tank. I mixed up two gallons of 91 octane and Ring Free and poured it into the tank. I shot a little starter fluid into the air box and hit the starter. After a few seconds, ignition. Normal cold idle, a little smoke, I assume from the oil I put directly into the cylinders yesterday. It quit smoking pretty quick. After a minute or two, I tried the throttle. She stumbled and died and was hard to restart. I let it run a while longer but then was getting lots of smoke near the exhaust "manifold". My valve cover gasket was leaking oil. I shut her down, disassembled everything back down to remove valve cover and it seems the gasket my have got a little kinked. I reinstalled everything and let it be. I'll try to start again tomorrow night. Here's how she sits at the moment:

IMG_5821_zps0tazrqfj.jpg


 
Put that thing together and take it out and ride the piss out of it. Hit redline a few times.

I bet its fine.

Change the oil next week.

smile.png


 
Last edited by a moderator:
Sounds pretty good to me. Too bad about that oil leak...... yep, warm 'er up and go for a ride. Recheck compression after that? I'll bet you don't need to.

 
Last edited by a moderator:
When you do get the FJR rideable, I'll say be gentle on the first few RPM pulls. In addition to stuck rings, the engine could have a lot of carbon on the pistons and valves.

Feed the engine the throttle it will take but don't push it if it bogs. The key is to work the rings and get them sealing again. Run it up to 5-6K and then back down on closed throttle...do this several times until the engine takes the throttle easier. Continue running it up with progressively more throttle and revs as it frees up and rings work free.

It might also be worth adding some Sea Foam directly to the oil, follow the directions with 1 oz / quart. Continue with throttle and revs and work those rings!

Just my $.02!

--G

 
When you do get the FJR rideable, I'll say be gentle on the first few RPM pulls. In addition to stuck rings, the engine could have a lot of carbon on the pistons and valves.
Feed the engine the throttle it will take but don't push it if it bogs. The key is to work the rings and get them sealing again. Run it up to 5-6K and then back down on closed throttle...do this several times until the engine takes the throttle easier. Continue running it up with progressively more throttle and revs as it frees up and rings work free.

It might also be worth adding some Sea Foam directly to the oil, follow the directions with 1 oz / quart. Continue with throttle and revs and work those rings!

Just my $.02!

--G
--G's two cents are golden and carry much weight here on the forum!

 
Top