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Discussion Starter · #1 ·
TL/DR
to get the head off a Tre K, do you have to drop the motor or can it be removed with the motor still in the frame?
(looking at it from a workshop labour hours / practicality point of view)

Backstory
the ignition coil for cyl 3 (? the one on the sidestand side) failed but I ended up doing about 50km on two cylinders to get it home. Took me about 6 months to get around to finding and then buying a set of TechAuto coils (55 quid each vs 170 from France or 140 from Italy for standard Sagems)
I was going to fit them myself but got stuck when I couldn't figure out how to undo the air box clamps on the throttle bodies so I gave up, put it back together, and threw it at my local indie shop (who had done the initial failed coil diagnosis).
they reported that the TechAutos fitted fine, had a nice spark, but the engine was still not running...
further investigation revealed a rusty bore in cyl 3 and coolant visible as well

so at the very least I have a blown head gasket, and at worst a crack or a warped cylinder head.*

I only paid $5.5k for it back in 2019 with about 8k on the clock, now has 18k.
the only 2 TREKs for sale in Oz (today) are 2008 as well at $7k & $8.5k, with a 2013 Amazonas at $13k

so that would give me a ballpark limit of $3k for the repairs (including parts & finding them) - say $100 per hour for 20 hours plus $1000 for parts ? does that sound reasonable ?

* I suspect a warp due to overheating - cyl 1 & 2 clean burn, cyl 3 dumping raw fuel at the lambda probe, ECU decides there ain't enough oxygen leftover in the exhaust so leans off the mixture so 1 & 2 now run lean and bl**dy hot while cyl 3 is cold - I was using a infrared thermometer on the downpipes and up the muffler and the muffler interior was about the same temp as downpipes 1 & 2 - about 217c iirc (downpipe 3 was about 140c)
 

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I would say almost impossible to remove the head in the frame, but I could be wrong. The head has the top engine mounts on it. It isn’t that big a job to drop the engine out.
 

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I would say almost impossible to remove the head in the frame, but I could be wrong. The head has the top engine mounts on it. It isn’t that big a job to drop the engine out.
No , the head comes off insitu, you have to release the top mount head to frame bolts, but can leave the motor in the frame, you can even take the cylinder block (barrells) off, take out con rods and pistons, there are ports under the crank you can get through to remove big end bolts. sump removal needs the exhaust off, (well the three into one).
 

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Thanks for correcting me Pete
Not a correction Glyn, Have done it , got the T shirt. not easy ,but do able. Even if you have to lift the bike by the forks in a good paddock stand and lie on the floor to get under the bike to get at the big ends. Its a dirty job but it has to be done.
 

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Would not have thought it was possible, but I think if I needed to get at the head again, I'd still remove the engine. I'd rather work that intimately on the engine with it on the bench.
 

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Would not have thought it was possible, but I think if I needed to get at the head again, I'd still remove the engine. I'd rather work that intimately on the engine with it on the bench.
Its a long story Errol, I started with a non running bike, took the tank off to get at the plugs, could not get one out.Had to get the head off to find out why , stripped more and drained down the fluids. Got the cams out etc , undid the top frame bolts. pulled the head off to find the carnage. Needed head, barrels , pistons. Gone to far by now so decided to keep stripping with the engine still in the bike, So sump off and found it was possible to get at the big end bolts, you have to rock the crank back and for, to get at one at a time.
Well I had got it apart so reasoned I could put it back together, which I did with good secondhand parts. Can send you a video of the rebuilt bike running, re mapped with a TNT map. I used TNT parts on the Tre K.
 

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I really meant thanks Pete I wouldn’t want to mislead about the stripping in the frame thing. You did well there access is a pig at the best of times.
 

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Discussion Starter · #9 ·
Would not have thought it was possible, but I think if I needed to get at the head again, I'd still remove the engine. I'd rather work that intimately on the engine with it on the bench.
so pull the engine out would be simplest...

any suggestions on what parts to get?
my guess would be a head gasket at least but is there anything else that should be replaced at the same time ... or does a head gasket come in a kit ?
anyone in Australia reliable to order from ?
or should I just go to Maniac Motors or one of the English dealers ?
 
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