Service manual contradiction: cylinder bore

[LiveandLetDrive]

I'm in the middle of refreshing the rings on my 2000 Tiger 885i and when the new ring gaps seemed excessively large in the old cylinders I went to check whether the cylinder sleeves themselves are in spec.

The service manual says:

Standard: 75.985-76.003mm
Service limit: 73.053mm

(That's from memory but I think it's right and the service limit number is definitely right.)

Wha? Doesn't service limit mean the max size before they're worn out? How could the bike ever have a ~73mm bore, would the pistons even fit? (Haven't measured their OD yet.) Maybe it's supposed to read 76.053mm for the service limit?


The cylinders themselves measure to 76.02-76.04mm (my mic only goes to the hundredth) so I am not clear whether I'm in spec or not. They still show crosshatching despite 75k miles so perhaps they were re-honed and they took off too much material? Regardless the new ring gaps seem too large so maybe I need to bite the bullet and order some sleeves, there goes another $300 on a bike which I'm planning to sell immediately for $2000 and already have $4k+ in! Some lucky devil is getting a well-maintained and upgraded ride. ('05 wheels, rotors, TOR exhaust, cat delete, and Corbin seat.)



In other news, I avoided buying Triumph's $250 cylinder sleeve remover by using $5 of hardware store parts (Oatley 3" test drain plug + longer 3/8" carriage bolt), but in the end they just popped out while I was bumping it over to get the next piston up for cleaning!

[Sin_Tiger]

It's unlikely the liners have been done in the interim, certainly my Steamer was like that when opened at 86k and there was no sign that she'd ever been opened up before.

The important thing is the ring gap for ring wear, usually the way to assess liner wear is to pop a new ring in and check it's within limits which would indicate your liner wear is OK. Check at upper and lower extremes of stroke stroke, that will give you a good indication of wear. There should be no discernable step at the top of the stroke. If the original hone marks are still visible you are talking microns of wear only at most so it's unlikely you need to do anything with the liners. I don't have the service data to hand so can't comment on the apparent contradiction.

I would normally expect the top rings and or the ring lands in the pistons to be the wearing area when the liners are in this condition but again I found very little and everything was reused. Don't be tempted to "clean" everything up too much, just enough that it's all smooth and free.

It's been said many times and will be again, DO remember to reseal the liner bases with Blue Hylomar, if you haven't got any to hand get some, don't trust anything else that you haven't had past experience with.

[LiveandLetDrive]

Confirmed on another forum that the Speed Triple (same motor) manual says 76.050mm service limit, so mine has a misprint!  Yeah I checked the gaps with the new rings and they're too high.  I only checked ring gap at ~5mm below the top of the worn area.  As close as I am to the limit I think it's new sleeve time...

I've always used black silicone and recently Permatex The Right Stuff in oil-exposed seal situations but I've heard of the blue stuff too.  Oddly my sleeves had nothing on the bottom but I've never had water in the oil.  Maybe the original wore away with time and miles?

[NortonCharlie]

Isn't the center cylinder larger than the other 2,  I could swear (in my 955 manual) that the center cylinder runs a bigger clearance.  Was that different for the 955's or am I dreaming?  I'd grab the manual and check but it isn't handy at the moment.

[NortonCharlie]

Finally got the manual out,  On the 955, the Cylinders are all the same size.  The #2 piston is .01 mm smaller in diameter.

[LiveandLetDrive]

Interesting.  Buying the sleeves, #2 was a different part number but they don't say why.  I didn't see any different ring gap or cylinder specs by position in the service manual but I didn't look at the piston diameter which hopefully I won't be messing with!

Ordering parts from Triumph through Bike Bandit takes absolute ages so I'm still waiting on my cylinder sleeves...