Replacing head gasket.

Sorry I didn't take any photos as I did this, next time I'll take photos and update this.

You do not need to remove the engine to do this. And this is for the 2kr I believe there are some differences with the 3ln like airbox?
Head gasket part number: 3ln-11181-00
cylinder head cover gasket part number: 1hx-11193-00



Remove:
1) all fairings (except front, unless you really want too <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: --> )
2) seat
3) tank/airbox cover
4) radiator
5) airbox and filter
6) carbs
7) exhaust assembly
8) drain coolant/water and oil
9) down tube frame on right hand side
10) spark plugs
11) cylinder head cover
12) generator cover
13) cam chain tensioner
14) oil delivery pipe
15) cam chain guides

** there are 2 different ways to do the rest of this**
a) if you have cam chain cutters and don't want to mess with the cam shafts (I don't know how to use cam chain cutters, haven't seen them); or
b) if you don't have cam chain cutters, you have to mess with the cam shafts (I tried getting the cam chain cutters from yamaha but the part number I supplied from the fzr400 manual didn't come up with anything on their computers)

a):
16) cylinder head

b):
16) camshaft caps
17) camshafts
18) cylinder head




1) should be fairly obvious, undo all the bolts.

2) pull lever in boot to open then pull seat up

3) tank cover has 6 bolts (mine were phillips head and I only had 4) 2 at the bottom where the seat goes and 2 at the bottom side easily visible. The other 2 are under the rubber intakes, you can just push that up and to the side to get the the 2 bolts (1 each side) or you can undo the rubber intakes if it's easier for you.

4) Undo the hoses going to the radiator (2) and the 3 mounting bolts, 2 at the bottom sides and one at the top center.

5) Undo the 4 clamps at the bottom of the airbox. (undo 2 from one side then the other 2 from the other)
And undo the 2 bolts at the top holding the airbox to the frame (mine only had one and even then it wasn't doing much of a job <!-- s:lol: --><img src="{SMILIES_PATH}/icon_lol.gif" alt=":lol:" title="Laughing" /><!-- s:lol: --> )
Pull the airbox off with the filter inside.

6) Undo the 4 clamps on the carb boots just like you did with the airbox. Undo the fuel hose on the back of the carbs at the top centre. Then either disconnect the choke and throttle cables before or after you pull the carbs off (I found it easier disconnecting the them after I took the carbs off) Don't tip the carbs upside down unless you don't mind fuel going everywhere. <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: -->

7) Undo the 8 nuts holding the exhaust pipes to the engine (there are no gaskets) and the muffler bracket bolt.

8) if you haven't already done so, drain coolant/water and oil.
Oil drain plug is at the front and bottom of the engine, should be easily identifiable.
Coolant/water drain plugs (3) 1 is bottom of the frame on the left side of the bike, you'll see the plug in the frame looks like it does nothing (doesn't hold anything on) it is before the kickstand. The other 2 are on the front of the engine below the exhaust outlets one on the left and the other on the right (these don't hold anything either) they also look like they are in for no reason.
Once the fluids are drained, you can flush the cooling system and flush the oil some more (if necessary, like when you blow a head gasket) then you can do up the drain plugs.
Oil drain plug: 43Nm (4.3m-kg, 31 ft-lb)
water/coolant drain plugs: 7Nm (0.7m-kg, 5.1ft-lb)

9) Ok, on the right side of the frame you'll see 4 allen key bolts (that's what they were for me) holding a section of frame to itself (2 at either end of this section) and there is a bolt holding this section of frame to the engine right next to the generator cover. Undo these 5 bolts, and remove.

10) take the spark caps off the plugs then get a 16mm (5/8 inch) spark plug tool (or a deep 16mm (5/8 inch) socket works too) then undo the 4 spark plugs. Inspect and replace if necessary.

11) undo the 8 bolts on the top of the cylinder head cover. Remove. Inspect the gasket.
(I personally don't see the need to replace this if it's in reasonable condition, like no scratches/nicks/cracks/etc)
part number: 1hx-11193-00

12) undo the 4 bolts (were allen key for me) and remove the generator cover.
**If you choose to remove the cam shafts from the cylinder head then go to step 12.
**If you choose to leave leave the cam shafts intact (you have a cam chain cutter) then you must align timing mark in the generator housing with the one on magneto. There is a line with a "T" next to it on the magneto (the center part that rotates with the crankshaft. Also there is a kind of pointer shaped (half arrow I suppose) bit of the generator housing around the top right. (at least that's what it is on the 2kr model, not sure if it's the same in the 3ln but I'm guessing it would be very similar).
To align them, turn the crankshaft Counterclockwise via the nut in the center of the generator housing/magneto.

13) The cam chain tensioner is situated below where the carb boots are in the centre. You will see a pipe that is held on by 4 bolts just below the tensioner (with 2 bolts either side of the tensioner for this pipe).
The tensioner itself has a bolt in the centre of it (to adjust the tension) and 2 allen key bolts (or they are on mine) holding it onto the engine, undo and pull out, careful not to lose any of the bits as you remove the tensioner.
There is supposedly a gasket here, but there didn't seem to be one or any remanents of one on my bike. I reinstalled with no gasket and it doesn't leak anything. I think the part number for the cam chain tensioner is: 5G2-12213-00
I got that from the Fzr250 parts list page 7, #8

14) The oil deliver pipe is at the front of the engine and goes from the oil pan (bottom) to the cylinder head. There are only 2 bolts holding it on (one at either end).

15) The upper and exhaust side cam chain guides need to be removed.
The upper chain guide is held on by 4 bolts which also hold part of the cam caps on.
The exhaust side chain guide is a bit fiddly, I used a pair of pliers to grip the top of this guide and wiggle it up and out, it does require a little bit of force.
Or just a sudden thought, while the upper guide is off, pull some chain slack from the intake side towards the exhaust side to allow the guide to be more free, then it may be a bit easier.

a) 16) Use the cam chain cutters, cut the cam chain.
Remove the rubbers from the cam caps (3 per cam cap, 12 in total).
Undo the 6mm allen key bolts (12). Note: refer to page 10 chapter 4 of the fzr400 manual for the proper undoing sequence.
Remove cylinder head and head gasket.
Replace head gasket. Head gasket part number: 3ln-11181-00
Note: clean out the cylinders, piston crowns/heads and anywhere else that you see needs it. (If you have had the gasket blown and there's oil and coolant/water everywhere)
If there is crap that wont come off of the piston crowns/heads or the cylinder head where the valves are, then you should take them to be acid bathed. (you will probably have to do further disassemlby of the engine to get the pistons out to be bathed, I can't help with that maybe at a later date when I do this, I just cleaned as much as possible off then left them and it seems to be running fine)

b) 16) Undo the 24 bolts (6 per cam cap) and remove (you will have already taken 1 bolt from each cap off when you removed the upper cam chain guide)
Also, take note of which cap was where, they are labelled with an I or E for intake and exhaust and 1 or 2 depending on left or right. But it's better to be sure so if you mark them yourself somehow (tape, marker, etc) you wont have trouble trying to read the markings that are there (or partially in my case).
In the manual it says to undo these in a crisscross pattern from outermost to innermost, but not anymore specific than that (no number order).

b) 17) Take note of which cam is which (intake or exhaust, labelled with I or E on one end, but be sure which is which!!) Play with the cam chain until you get enough slack to remove one of the camshafts, then remove the other, at the same time make sure the chain DOESN'T fall down, even a little, into the crankcase. It is a (*($&%(&(@(*$(#^(% to get back up. (took em an hour or 2 <!-- s --><img src="{SMILIES_PATH}/icon_mad.gif" alt="" title="Mad" /><!-- s --> <!-- s:alcoholic: --><img src="{SMILIES_PATH}/icon_all_coholic.gif" alt=":alcoholic:" title="Alcoholic" /><!-- s:alcoholic: --> ) You can use something to hook the chain up to part of the frame or wherever to help.

18) Undo the 6mm allen key bolts (12). Note: refer to page 10 chapter 4 of the fzr400 manual for the proper undoing sequence.
Remove cylinder head, be careful with the cam chain as you lift the head out, ensuring it doesn't fall into the crankcase. then remove the gasket and replace.
Head gasket part number: 3ln-11181-00
Note: clean out the cylinders, piston crowns/heads and anywhere else that you see needs it. (If you have had the gasket blown and there's oil and coolant/water everywhere)
If there is crap that wont come off of the piston crowns/heads or the cylinder head where the valves are, then you should take them to be acid bathed. (you will probably have to do further disassemlby of the engine to get the pistons out to be bathed, I can't help with that maybe at a later date when I do this, I just cleaned as much as possible off then left them and it seems to be running fine)

 

Note: The torque settings are from the fzr400 which I used and have had no troubles, I'm not sure if there is much of a difference between the fzr400 and the fzr250 torque settings.


Installation/Assembly:
a):
1) head gasket and cylinder head

b):
1.0) head gasket and cylinder head
1.1) camshafts
1.2) camshaft caps

2) cam chain guides
3) cam chain tensioner
4) check timing marks
5) oil delivery pipe
6) generator cover
7) cylinder head cover
8) spark plugs
9) down tube frame on right hand side
10) drain bolts (water/coolant and oil)
11) exhaust assembly
12) carbs
13) airbox and filter
14) radiator
15) fill oil and water/coolant, check running engine
16) tank/airbox cover
17) seat
18) fairings

Steps 5 - 10 have no specific order, so if you want to put the cylinder head cover on before the generator cover and oil delivery pipe (for example) then feel free to do so!



a) 1) When putting the head gasket on, you'll notice on one side it says "HEAD", face this side upwards. Put the gasket on.
While you're here you might as well check that the timing mark in the generator housing and the one on the magneto are lined up (you'll see the first and fourth pistons at TDC, where the first will be on the compression stroke).
Turn the crankshaft via the nut in the center of the generator housing/magneto Counterclockwise to align.
You must do this otherwise you may damage the valves.
Now put the cylinder head on, the timing marks on the cam cap and camshafts should be aligned, if not you'll have to take the cam caps off and realign the marks.
Then tighten up the 12 bolts to 25Nm (2.5m-kg, 18 ft-lb)
Note: refer to page 73 chapter 4 of the fzr400 manual for the proper tightening sequence. It's best to tighten in increments, say all to 15Nm then all to 25Nm. Or more if you so desire.
Then place the rubber caps (12) back into the cam caps (where the head bolts go).
Now use the cam chain cutter to install the new chain link/joint (to replace the one you cut earlier).
Note: I have never seen cam chain cutters let alone used them, so I can't help you with how you're meant to do this part.

b) 1.0) When putting the head gasket on, you'll notice on one side it says "HEAD", face this side upwards. Put the gasket on.
While you're here you might as well check that the timing mark in the generator housing and the one on the magneto are lined up (you'll see the first and fourth pistons at TDC, where the first will be on the compression stroke).
Turn the crankshaft via the nut in the center of the generator housing/magneto Counterclockwise to align.
You must do this otherwise you may damage the valves.
Now put the cylinder head on.
Then tighten up the 12 bolts to 25Nm (2.5m-kg, 18 ft-lb)
Note: refer to page 73 chapter 4 of the fzr400 manual for the proper tightening sequence. It's best to tighten in increments, say all to 15Nm then all to 25Nm. Or more if you so desire.

b) 1.1) Now, find the exhaust side camshaft, it will have an "E" on one end of it (and "I" for the intake side camshaft). Find the timing mark on the circular disc end of the camshaft, now put the camshaft into the exhaust side spot with the timing mark facing outward and with the chain going around the cam sprocket. You can get the cam cap labelled "E1" and place it in it's spot to see if the camshaft timing mark lines up with the timing mark on the cap, if not realing the camshaft.
Now that it's nicely lined up, get the chain so it is tight upto and around the sprocket of the exhaust camshaft.
Next install the intake side camshaft with it's timing mark facing the same as the exhaust side cam and keep the chain tight over this as well, you'll notice a lot of slack on the intake side. Don't worry that's meant to be there, the cam chain tensioner is used to tighten that side up. <!-- s:wink: --><img src="{SMILIES_PATH}/icon_wink.gif" alt=":wink:" title="Wink" /><!-- s:wink: -->

b) 1.2) Get the camshaft caps, identify which is which (E1, E2, I1, I2) and place them in their appropriate places. Where E1/I1 go on the side with the timing mark on the camshaft and E2/I2 on the other side.
Tighten the bolts (24, except the inner/center most 4) to 10Nm (1.0m-kg, 7.2ft-lb).
In the manual it says to tighten these in a crisscross pattern from innermost to outermost, but not anymore specific than that (no number order).
As with the cylinder head bolts, do these up in increments.

2) Put the exhaust side cam chain guide in, then the upper guide and bolt (4) that down to the same torque as the rest of the cam cap bolts.

3) There is supposedly a gasket for the cam chain tensioner, but there didn't seem to be one or any remanents of one on my bike. I reinstalled with no gasket and it doesn't leak anything. I think the part number for the cam chain tensioner is: 5G2-12213-00 I got that from the Fzr250 parts list page 7, #8
Now, undo the end cap bolt, watch out for the spring and other bits and pieces. Then push the tensioner back into itself as far as it goes. Install the tensioner without the little bits (bolt, spring, washer, etc) and bolt (2) that down to 10Nm (1.0m-kg, 7.2ft-lb).
Next install the little bits and bolt the end cap to 20Nm (2.0m-kg, 14ft-lb). You will hear the tensioner clicking as it pushes against the chain to tighten it.

4) To see if everything is good so far in the way of timing, turn the crankshaft via the nut in the center of the generator housing/magneto Counterclockwise several turns (the more the merrier <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: --> ) and realign the timing marks in the generator housing/magneto.
Check ALL timing marks (camshaft, cam cap, generator housing and magneto)
**IF all line up nicely then it's all good and you can continue.
**IF the timing marks on the camshaft and cam caps don't line up but the generator housing and magneto timing marks do, try turn the crank one more turn. Check again. If they still don't line up, you have to backtrack and reinstall the camshafts and cam caps.

5) The oil delivery pipe should go on only one way, bolt (2) it on to 20Nm (2.0m-kg, 14ft-lb).

6) Bolt (4) the generator cover back on, to 10Nm (1.0m-kg, 7.2ft-lb).

7) Put the gasket onto the cylinder head cover (if you got a new one, or took the old one off) then place the cover on and bolt (8) to 10Nm (1.0m-kg, 7.2ft-lb).

8) Install the spark plugs, torque them to 13Nm (1.3m-kg, 9.4ft-lb) and put the spark leads/caps on.

9) bolt (5) the down tube frame on the right side back on with the upper 2 bolts torqued to 60Nm (6.0m-kg, 43ft-lb), lower 2 to 33Nm (3.3m-kg, 24ft-lb) and the bolt that goes next to the generator (a.k.a. engine mount bolt) 55Nm (5.5m-kg, 40ft-lb).

10) If you haven't already done so do up the drain plugs.
Oil drain plug: 43Nm (4.3m-kg, 31 ft-lb)
water/coolant drain plugs: 7Nm (0.7m-kg, 5.1ft-lb)

11) install the exhaust assembly, torque the flange nuts (8) to 10Nm (1.0m-kg, 7.2ft-lb) and the muffler bracket bolt to 20Nm (2.0m-kg, 14ft-lb).

12) Connect choke and throttle cables (before or after seating the carbs, whichever you prefer), same with the fuel hose.
Push the carbs into their boots, check to see that it's seated properly, then tighten the clamps up as tight as you can. Air leak is bad! (Causes engine to try and rev higher and higher)

13) I found the airbox to be a nuissance when installing it, just didn't want to seat properly! Anywho, push the airbox onto the carbs, it's easier with 2 people, one each side of the bike, both push down on their side of the airbox and up on their side of the carbs.
Check that it's seated properly and tighten the clamps up tight (doesn't need to be as tight as the carb boots).
Bolt (2) the top of the airbox to the frame.
Install the filter (if it was removed, or if you got a new one).

14) You can either mount the radiator or connect the hoses first, whichever you find easier. Tighten the clamps on the hoses and torque the 3 bolts to 7Nm (0.7m-kg, 5.1ft-lb)

15) Fill the oil and water/coolant. Start the engine and let it run a couple of minutes, check for any leaks, listen to the engine, rev it a bit and listen to the engine, check for leaks again. Turn engine off.
If all is good (engine doesn't sound like it's misfiring, backfiring, running rich, etc, etc.) then you've done a good job! And you're pretty much finished.
Might as well fill up the coolant some more if need be.
You could even take the bike for a little test ride if you so desire, although it's weird without the tank cover to grip to. <!-- s:rofl: --><img src="{SMILIES_PATH}/icon_razz.gif" alt=":rofl:" title="Rofl" /><!-- s:rofl: -->

16) put the tank cover on do up the 6 bolts, and if you removed the rubber air intakes bolt them back on.

17) place front of seat in first then clip the back in.

18) should be fairly obvious, do up all bolts.


OH, I just realised one thing I didn't do...... the oil filter! <!-- s:roll: --><img src="{SMILIES_PATH}/icon_roll.gif" alt=":roll:" title="Rolling LoL" /><!-- s:roll: -->
Go to http://www.fzr250.com/viewtopic.php?t=661 for oil filter info <!-- s:wink: --><img src="{SMILIES_PATH}/icon_wink.gif" alt=":wink:" title="Wink" /><!-- s:wink: -->

<!-- s --><img src="{SMILIES_PATH}/icon_redface.gif" alt="" title="Embarassed" /><!-- s -->

 

CALVO: the head gasket was around $30 and the cylinder cover gasket was around $56.

Thanks for the info there Ciaran, I did realise that bits of carbon deposit would cause damage to the engine, so I just got rid of the loose stuff with a clean rag.