R-6 Head Gasket

[Kilbane83]

I had to tear my engine apart to replace a bent shift fork in the tranny (write up to follow in the future if anyone requests it) and while I was in there I thought I'd play around a bit. Did a bit of looking around and saw some info on the R6 header gasket being slimmer than the FZ6. Mechanically this means there is less clearance between the valves and the pistons. This would increase the compression ratio of the engine and improve power and gas milage. I figured hell why not, it costs the same as the FZ6 gasket, and should have worked.

Well it doesn't. Physically the 04 R6 engine is almost exactly the same in dimension, even uses the same part numbers for the pistons and valves, but with the R6 gasket there is a compression leak, I think between cylinders I haven't pinned it down it's not important, it just won't work. Maybe the cylinder head mating surface is just different enough to cause problems, I dunno. Save yourself $50 and a couple hours, It does not work. :surrender:

*Update*
Well, it turns out it does work, my original guess was correct. After reading opnwhlmnd's post, I decided to try again. Worked fine. I don't know if the first gasket was a bust or what, eitherway it does work. Unfortunatly I had other issues so I can't give you any real feedback on the change. It seemed to have a bit more pep, but that could have been a mental thing. Dunno I may try again sometime and report back.

 

[Discofrank]

thats a bugga

did u compare the new gasket with the old? to see if they where different


did u use NEW head bolts?

 

[Cali rider]

I had to tear my engine apart to replace a bent shift fork in the tranny (write up to follow in the future if anyone requests it)...

Please share this experience when you have time. As many FZ's are getting up there in mileage, major engine/transmission repairs are going to appear and your information will be helpful to all.

...I think between cylinders I haven't pinned it down it's not important, it just won't work. Maybe the cylinder head mating surface is just different enough to cause problems, I dunno. Save yourself $50 and a couple hours, It does not work. :surrender:

Follow up with this issue as well. Curious as to the source of failure..

....did u use NEW head bolts?

I'm thinking the same thing, as well as torquing the bolt pattern out of sequence.

 

[Norbert]

I had to tear my engine apart to replace a bent shift fork in the tranny (write up to follow in the future if anyone requests it) and while I was in there I thought I'd play around a bit. Did a bit of looking around and saw some info on the R6 header gasket being slimmer than the FZ6. Mechanically this means there is less clearance between the valves and the pistons. This would increase the compression ratio of the engine and improve power and gas milage. I figured hell why not, it costs the same as the FZ6 gasket, and should have worked.

Well it doesn't. Physically the 04 R6 engine is almost exactly the same in dimension, even uses the same part numbers for the pistons and valves, but with the R6 gasket there is a compression leak, I think between cylinders I haven't pinned it down it's not important, it just won't work. Maybe the cylinder head mating surface is just different enough to cause problems, I dunno. Save yourself $50 and a couple hours, It does not work. :surrender:

At least you had the ballz to try this! :thumbup:

 

[Kilbane83]

did u compare the new gasket with the old

Yeah, the difference really is the FZ6 has a few more holes around the water jacket. I know the water jacket isn't leaking into the cylinders as there is no fluid in them. It isn't leaking into the oil either cause the oil has no water in it, nor vise versa. Only thing I can figure is pressure is going between cylinders, or out of the cylinders into the waterjacket. The coolant I drained did have a very small amount of film from gas it looked like, but that could have been due to not fully flushing the system yet, or the funnel I was using wasn't very clean.

The rings are sealing fine, if you put your hand over the cylindes w/o the head cover on you can feel it suck and push significantly, without loss in pressure if you hold it there, as it should.

did u use NEW head bolts?
as well as torquing the bolt pattern out of sequence.

New bolts aren't needed. The torque pattern is right I did it 3 times. Both the R6 and FZ6 torque settings and patterns are the same, you torque to 14ft Lbs in order, then go back and torque to 36ft lbs in order.

First test I had proper compression on cylinder 3, barely any on 1 and 4, and none on 2. Drained all the fluids, dropped the engine back out. (Note.. check compression before putting the engine back in the frame....:eyebrow
Took it apart reset the gasket and checked everything out, then I had a little compression on 2, but none on any of the other 3.
Last time I took it apart I had compression on 3, some on 4, none on 1 and 2

I had the timing out 180degrees at first, I lined it all up on the intake stroke instead of the compression stroke, :banghead:. Fixed that once I realized it before I even tested the compression for the first time. After I was only getting compression on cylinder 3, I checked the timing again while watching the intake valves through the throttle boddies, it was spot on. The next 2 tests the camshafts where out so the valves where diffinatly closed.

 

[Discofrank]

New bolts aren't needed.

YES THEY ARE

head bolts STRETCH

and since yours have stretched i can guarantee that u are not getting the full torque required on the head gasket

GET NEW HEAD BOLTS! ffs

and make sure u get the damn valve timing correct otherwise even with the correct gasket u going to get NO compression


strange that the head has more water jacket holes, thats what i would be concerned about as it may affect the cooling of the bike


also i thought our bikes engines where based on the 02 r6 not the 04?

i also think u have the wrong year r6 head gasket a search
Welcome to OEM Motorparts, Original parts for Aeon, Aprilia, BMW, Buell, Cagiva, Dinli, Derbi, Ducati, Gilera, Harley davidson, Honda, Kawasaki, KTM, Moto Guzzi, Peugeot, Piaggio, Suzuki, Sym, Tomos, Vespa and Yamaha motorcycles, mopeds and scooters.

shows the 02 r6 and fz6 as diff part numbers but similar designs in relation to the water jacket holes..

 

[urbanj]

Do a leak down test and you can figure out where the leak is without taking it apart and putting it back together over and over again. Just listen for where the hiss is coming from.

Make sure the timing is right as well as the valves are adjusted.

 

[RJ2112]

I'd take a very careful look at the valves.... if you cycled that motor enough to get readings on all four cylinders with the cams 180 out, there's a chance you had valve to piston contact. Especially if the R6 gasket you used is thinner.

I agree that if there is no valve action (cams out) there is no way to get good compression numbers. You have to compress air to get the reading.

 

[opnwhlmnd]

Have a R6 head gasket on mine and it's worked perfectly no problems for around 5000 miles now. Fits perfectly.

I'm getting ready to install an even thinner .050 thick R6 head gasket to up the compression to 13:1

There are extra holes in the R6 head gasket to speed up the water flow but they just open up the same jacket. They don't uncover a different water jacket.

I would closely for some bent valves with trying to crank it with the timing 180 degrees off. Even if the piston didn't contact a valve you had fuel in the cylinder on a compression stroke and the piston trying to compress the extra fuel will sometimes bend a valve or in worse case senario a connecting rod. Something had to give either a valve, rod, or blown head gasket.

If you are going to keep re-torqueing the same head gasket get some Permatex Copper Spray-a-Gasket sealer and spray it on both sides of the gasket before you re-install it. If can't find that you can also use aluminum spray paint and paint the gasket with that before installing. It will seal it also on a used gasket.

But please don't alarm everyone with saying it will not work just because it was installed incorrectly.

This mod works perfectly if work is done right.

.

 

[Discofrank]

Have a R6 head gasket on mine and it's worked perfectly no problems for around 5000 miles now. Fits perfectly.

I'm getting ready to install an even thinner .050 thick R6 head gasket to up the compression to 13:1

This mod works perfectly if work is done right.

.

i knew it


what year r6 gasket did u use.. ? and was teh gain noticeable?

 

[Kilbane83]

head bolts STRETCH

Yes they can, in a steel block, or TTY bolts. Not likely with steel bolts in an aluminum block. Niether the service manual, nor the Haynes manual recommend replacing them, and the Haynes recommends replacing all kinds of odd bolts and washer. It has been pretty cold here lately, so that may be causing false results on the torque settings now that I think about it.

I would closely for some bent valves with trying to crank it with the timing 180 degrees off

I cranked it by hand, I wouldn't think that'd be enough force to bend anything without feeling it. The valves are all seated properly with the cam off so they're sealing, and there is no way the rod are bent. There was no compression on some of the cylinders from the start.

Have a R6 head gasket on mine and it's worked perfectly no problems for around 5000 miles now. Fits perfectly.

I thought it should. I'll try the gasket sealer you mentioned. Maybe I'm just not getting a good seal for some reason. I've never dealt with a metal head gasket before. Possibly a bad gasket from the start or something I dunno.

 

[opnwhlmnd]

I used a head gasket from a 2003 R6. Yamaha part number 5SL-11181-00-00

If you only cranked by hand you wouldn't have bent anything or put fuel in the cylinders.

Did you happen to torque the bolts dry?

Get some ARP bolt/stud lubricant and put a dab on the threads you'll get a much more accurate torque reading.

You can rent a cylinder leak down guage at Autozone or whatever store like that you have near you.

Remove all the plugs and get #1 on top dead center compression stroke. Thread leak down gauge line into plug hole an hook to air compressor. If it leaks down more than 10% you will hear the air coming from the source. If you hear from exhaust, exhaust valve not seating. If you hear from throttle body, intake valve not seating. Hear from radiator, head gasket not seated. Hear coming from adjacent plug hole, again head gasket not seated. You will hear a small amount from the crankcase as the rings won't seal air 100%.

Repeat procedure for the other 3 cylinders. Make sure each one is top dead center compression stroke.

Much more accurate than a compression gauge

.

 

[krid80]

I used a head gasket from a 2003 R6. Yamaha part number 5SL-11181-00-00

If you only cranked by hand you wouldn't have bent anything or put fuel in the cylinders.

Did you happen to torque the bolts dry?

Get some ARP bolt/stud lubricant and put a dab on the threads you'll get a much more accurate torque reading.

You can rent a cylinder leak down guage at Autozone or whatever store like that you have near you.

Remove all the plugs and get #1 on top dead center compression stroke. Thread leak down gauge line into plug hole an hook to air compressor. If it leaks down more than 10% you will hear the air coming from the source. If you hear from exhaust, exhaust valve not seating. If you hear from throttle body, intake valve not seating. Hear from radiator, head gasket not seated. Hear coming from adjacent plug hole, again head gasket not seated. You will hear a small amount from the crankcase as the rings won't seal air 100%.

Repeat procedure for the other 3 cylinders. Make sure each one is top dead center compression stroke.

Much more accurate than a compression gauge

.

100% dead on. Are you a mechanic,openwheel?

 

[opnwhlmnd]

100% dead on. Are you a mechanic,openwheel?

Yes I am.

Honda certified master technician automobiles and cycles. Toyota certified master techncian automobiles.

.

 

[Shinn]

i knew it


what year r6 gasket did u use.. ? and was teh gain noticeable?

Bringing this question up again. I would love to know the difference between the 2 gaskets, and if anything is noticeably different. PS, I am in awe of your mechanical skill. I look at an engine and get confused.

 

[opnwhlmnd]

Bringing this question up again. I would love to know the difference between the 2 gaskets, and if anything is noticeably different.

The R6 head gasket is thinner. It will raise the FZ engine compression from 12.2 to 12.4

It will give you a little more HP through out the entire rpm range. With that small of a change I would guess 1 1/2 - 2hp at the most is all the gain is.

I installed mine at the same time as R6 cams so can't tell you what gasket alone feels like seat of pants wise.

.

 

[turbid]

the cams that you used are also from the 2003 r6, could you give the part number pls? sounds a nice mod to do when the time comes to adjust the valves

 

[krid80]

The R6 head gasket is thinner. It will raise the FZ engine compression from 12.2 to 12.4

It will give you a little more HP through out the entire rpm range. With that small of a change I would guess 1 1/2 - 2hp at the most is all the gain is.

I installed mine at the same time as R6 cams so can't tell you what gasket alone feels like seat of pants wise.

.

did you do any before and after dynoing?

 

[Discofrank]

the cams that you used are also from the 2003 r6, could you give the part number pls? sounds a nice mod to do when the time comes to adjust the valves

with the cams u will loose all that wonderfull low down torque our bikes produce



i can do 30kmhr in 6th and pull away easy

 

[opnwhlmnd]

with the cams u will loose all that wonderfull low down torque our bikes produce

NO you will not lose low end torque with the cam swap. It actually gained some low end torque with the cam swap. Love how people on this forum speculate that any mod made is a disaster.

Yamaha gained the low end torque on the FZ with smaller throttle bodies and different intake tract.

The duration on the R6 cams actually improve the low end torque on the FZ.

Also the FZ cams are solid cast steel and the R6 cams are hollow billet cams. Big rotating weight savings. The cam sprockets from the R6 are much lighter also.

Part numbers are

5SL-12170-00 and 5SL-12180-00

I have a set of R6 cams with cam sprockets for sale if anyone is interested. Engine I took them from had 2000 miles on it.

.