A look at the 2.5 Innards - DIY 20K mile service, including valve clearance check and shim replacement

Part 1
This includes valve clearance check and shim replacement. Also air, fuel, spark plug and coolant replacement, and bleeding the clutch.
This is a work in progress, so edits and further information to come...

• Get the service manual here..

Take photos as you go to document wire and hose routings, etc.

• Remove fuel tank (page 796 in manual), Plenum Cover and air filter (136), Fuel Filter (142), Spark Plugs (154)
• See processes above here with photos....

• Remove Evap Canister (923)
• Camshaft Cover (250)

Triumph just has to do this- one of the bolts holding the camshaft cover is barely accessible. I made this simple tool to get that one off... It's on the right side, rear. I cut off some of the shaft of a 5/16th driver and bought a 1/4" open end from Home Depot (they sell a good selection of single tools).



The manual says to remove the left side cover- not necessary. Remove the right one (pops off) to help with removing the bolt above.

Be sure to remove the bracket in the back attached to this bolt.

There is another PIA bracket attached to the cover in the front and the brake line. I was able to lift it high enough to work out the cover after sliding it up the brake line and spinning it out and away as much as I could. I removed everything on it after I removed the radiator, as seen here.



No need to remove the radiator unless you need to replace shims.

Here's the bracket after I spun it out of the way (second photo). It's also attached to the brake line. The first photo shows a hose box that's attached to it. There's also a couple of other things. Without the radiator out you may just have to work around it as I did.



With the bolts and brackets out of the way the cover was stubborn about coming off. The gasket was sticking pretty good. I used a rubber mallet and small piece of wood to *gently* tap up on the edge of the cover. It needs to lift straight up (not tilted). Take your time. Be gentle. It'll come.

The service manual instructs you to remove the cover from the left side of the bike. Well, you're going to have to jump over the fuel connect and it's fragile. I got it out on the right side easily and think that's a typo along with the need to remove the left side cover.

Here's what you'll see. The "springie" things, btw, are decompressors. They don't have those on the 2.3 bikes.



Measure your clearances. If good- great (I'm never that lucky)! Reverse order and go ride. If off, you'll need to pull the camshafts in order to replace some shims.

Next...

• Radiator Removal
• Clutch Cover Removal

Part 2
At this point if you've determined you need to replace some shims. You'll need several special tools

• Timing Chain Tensioner Socket (T3880649) - This seems to just be a large socket. I used a 1 1/8" that was a tad loose, but worked just fine. A 34mm might be the exact one. Not sure why it's sold as a special tool
• Camshaft Timing Bar (T3880502) - I can't believe I paid for this, but now you don't have to. This is simply a flat bar of steel: 240mm X 24mm x 4.93mm
• Crankshaft Locking Pin (T3880501) - This one you'll need
• Timing Chain Tensioner (T3880651) - This one is also required. Not to be confused with The camshaft drive chain tensioner on your bike.
• Timing Torque Limiter (T3880609) - I purchased a torque setter off Amazon instead for a lot less

and some parts...

• O ring for the cam chain tensioner (T3601276)
• Clutch Cover Gasket (T1264070)
• Clutch Slave Cylinder Gasket (T1171711)
• Fuel Filter (T2407046)
• Air Filter (T2201813)
• Spark Plugs (NGK LMAR8A9 / aka NGK 4313)
• Coolant - Zerex G05 50/50
• Hot Cams 9.48mm Complete Shim Kit HCSHIM02

• Coolant Drainage (937)

• Coolant Expansion Tank Removal (1516)
• Radiator Removal (948)

• Clutch Cover Removal (259)

The water pump is part of the clutch cover. All this needs to come off so you can turn the crank where the pump was attached. I think attempting to turn the rear wheel, as you do to check valve clearances would not be an option given the procedure.


Remove the upper radiator hose and other things (including that front bracket I mentioned earlier, that is now swung out of the way) so that you can see the camshaft gears.

Remove Crankshaft Locking Pin Plug- follow directions and insert tool (slides all the way in if aligned correctly) as seen here...



More to come....

Journeyman28778 said:

• Coolant Drainage (937)

• Radiator Removal (948)

• Clutch Cover Removal (259)

The water pump is part of the clutch cover. All this needs to come off so you can turn the crank where the pump was attached. I think attempting to turn the rear wheel, as you do to check valve clearances would not be an option given the procedure.


Remove the upper radiator hose and other things (including that front bracket I mentioned earlier, that is now swung out of the way) so that you can see the camshaft gears.

More to come....

Click to expand...

Ah. There's that rattle chain.

Adjustable cam gears nice, no more inspection cover and crank driving water pump. Those cam chain guides look awesome.

big job it seems, nice post, lets see how the adjustment goes or even if it needs adjustment, in some bikes I reckon they didnt require adjustment (not sure why(?)).

• Remove Plenum (834)
• Remove Camshaft Drive Chain Tensioner (290) - No special tool required. Takes 24mm socket
• Remove Camshafts (312)

Under bucket shim exposed (bottom left). Exhaust (left) and Intake camshafts.

imcool said:

big job it seems, nice post, lets see how the adjustment goes or even if it needs adjustment, in some bikes I reckon they didnt require adjustment (not sure why(?)).

Click to expand...

It's a much bigger job than on the 2.3s, especially if you need to swap shims.

Several of my clearances were out of spec, just waiting on another part from Hermy's.

I'd sure like to know how much Triumph charges for the 20K service, with or without any shim replacements.

Journeyman28778 said:

I'd sure like to know how much Triumph charges ....

Click to expand...

Not sure that you would really.....

Journeyman28778 said:

It's a much bigger job than on the 2.3s, especially if you need to swap shims.

Several of my clearances were out of spec, just waiting on another part from Hermy's.

I'd sure like to know how much Triumph charges for the 20K service, with or without any shim replacements.

Click to expand...

I'd like to know how much @Journeyman28778 would charge to do it.

Shim under bucket type valve arrangements are typically more expensive to maintain than shim over bucket. They do allow engines to rev higher without the risk of spitting out a shim. I can replace my shims on the 2.3 model without pulling cams but on the 2.5 model... it's another story as we can see. Thanks @Journeyman28778 for enlightening us.