hello,
I did order a gasket for the (right side) cover...he did not mention any "bond" so I presume it is a rubber or paper gasket, next week I 'll know more

the XT workshop manual (you can find the link to download it under the treat ( XT workshop manual)
I did need the help of some Internet wizard to get it downloaded completely,(I am an ignorant myself) but he succeded , he will bring me the CD and a printed version

see U (and have fun )
Pol

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Yamabond is a sealant ,it comes in a tube ,it is very good for sealing metal to metal joints .
The normal one to use is Yamabond 4 , or another one you could use is Three Bond 1104 ,which I think is made by 3M .

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Blessed are the cracked, for they let in the light. - Spike Milligan
"When you come to a fork in the road ,take it ! When you come to a spoon in the road ,take that also ."

Hi Pol and Dodger,
Thanks for the info. My engine is a 3AJ00 (I guess the last bit is the year of manuf). I am not too sure any more where the oil is coming from - as discussed earlier in this thread, it is not easy to tell when it is blowing around in the wind.

I cleaned up the bike, took it for a ride and tried to watch it at the same time - got a bit carried away though and forgot for a while; the next time I looked there was quite a bit of oil on both sides of the engine!! On the right it is not easy to see anyway while riding because of the exhaust pipe.

Pol,
Do you have the same engine (3AJ)? If so, do you have part numbers for the gasket(s)? I'll have a look at that thread for the manual after this posting anyway. Have you got any hot tips for removing the crankcase cover (things to look out for and that sort of thing!)?

Dodger,
Ta for that; there is no mention in my info about different types of Yam Bond!

Cheers,

Dave

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Dave

Well, I have now figured that the Yam Bond stuff is for the joint in the 2 halves of the crankcase itself and not the covers (so that's OK then!).

Pol,
I did the search and I now have loads of downloads of manuals from earlier threads on here, including the Yamaha part numbers: ref above, I confirm that there are indeed gaskets for both crankcase covers (and I now have the numbers:- RHS = 4DW-15462-00).

So, now I have to clean up the engine (again!!) and run it to find out just where the oil leak is (problem is that the oil does not appear on ticking over).

Dave

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Dave

Pol,
Sorry to have butted in on your thread with my own problem, but it was because we seem to be dealing with a very similar issue.


Everyone who is interested!,
My situation now is:-

I had the "great" idea of wrapping masking tape around the crankcase cover joints on both sides of the bike wherever I thought the oil leak to be; this based on the earlier suggestion of using some kind of powder for this purpose; so with the tape wrapping in place I have just got back from riding the bike.

The result is that on tick over with a warmed up engine there is no obvious evidence of oil leaking. After riding about a mile at low revs there are signs of slight oil weeping around the back of the engine with nothing significant on or around the masking tape.
After riding about another mile at higher revs there was a "lot" of oil "swilling" about behind the engine and it looks very much as if it is coming from the gasket between the engine cylinder and the crankcase. The masking tape was still intact and slightly oil stained from splashing oil but it had not lifted off and there was no sign of oil coming from under the tape. Also, there is no sign of oil coming from the cyl gasket at the front of the bike i.e. it is quite localised to behind the engine.
I have tried tightening the bolts around this area (along with other bolts in general) but am concerned about stripping threads if over-tightened (can't get a torque wrench in there).

Grateful for any advice about the way forward for me!! Right now I feel like doing as Pol mentioned above and going for a trade-in for whatever it is worth in this condition!!!!!!!!!!!!!
In particular, I have not stripped down an engine before.


As a recap, I haven't had this bike very long, I don't know it's history but it is a low mileage TT600R, 2001 model with the 3AJ00 engine. I have had the 2 flexible oil pipes off the top of the crankcase and they seem to be not blocked and in good condition.

Cheers,

Dave

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Dave

I've been reading a cd manual for this engine - the bits about stripping the engine anyway!.
I'm in two minds about attempting to change the cylinder gasket myself; like Pol in earlier posts in here, "on a bad day" I am tempted to shop around for a trade-in for another bike and, there again, on another occasion, I think that it can't be all that bad!!

So, I am still looking for anyone who can give advice about the level of difficulty involved - from reading the manual I would need a gasket set & I should be able to get the cylinder head off without dismantling the valves/cylinder head; does anyone disagree with this?
Also, the cylinder will then come off more or less directly and then I can change the leaking gasket.

Specific questions (I am thinking of doing this with the engine still in the frame):-

1. What to look out for in both the dis-assembly and re-assembly? e.g. getting the cylinder back over the piston rings when putting it back on the bike.
2. Should anything else be replaced while the engine is opened up? (bolts?).
3. Anything "awkward" about putting the timing back in place? In fact, should the bike engine be stripped with the timing in a particular "position"?
4. Should the engine bolts be "loctited" on re-assembly or not?

Those are the questions that came to mind from reading, but "reading" is not the same as "doing" I have learnt the hard way in the past so ANY advice on this subject, for or against is very, very welcome!!


Quite a few folk have read this thread so one or more of you must be able to advise,

Thanks,

Dave

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Dave

Just a thought, if you have recently oiled your air filter, or if the oil from the breather is blowing in to the airbox. You can get it dripping from the airbox seam on to the sort of area you refer to. I chased my tail for ages once looking for a leak on mine.

Dave,

The answers to your questions are all to be found in the manual, if it's not clear in the factory one (which is aimed at mechanics) then ideally get yourself one from say Clymer or Haynes (assuming they do/did one for the XT?). It would take someone an age to tell you how to strip and rebuild the top end of the engine in the detail you need if you've not done anything like this before wheras it'll all be in a anual including photo's etc.

If you are handy and have a good quality toolkit then doing the job yourself can be very rewarding but there are many things that you could do wrong unless you take care and follow the intructions carefully.

Are you sure the head/cylinder will come off with the engine in the frame? If the manual says it will fair enough, I just can't remember!


Finally, as modern bikes go, the XT is a simple one and relatively easy to work on and learn from, so good luck. Take it slow, don't force anything and when you put it back together make sure everything is surgically clean.

Leigh,
I am pretty sure that it is the gasket following my "experimentation" described earlier. In addition the oil tank on the TT600R is much nearer to the oil leak than the airbox which is some distance from the engine, as it happens, and the oil tank is oil tight and clean in appearance. When I said earlier that the leaked oil is "swilling" about, this equates to the dip stick going from showing full to low in a ride out of something over 100 miles: for me that is a fair bit of oil to lose.
Having said that, I am going to do the test with masking tape once more to confirm what is going on but it will be around the cylinder gasket next time.

Rickg,
I have a manual on cd - it is not as detailed as those published with many pics (but it has a few) & it gives the basics including exploded line diagrams and it does say that the cyl and piston can be inspected with the engine in the frame - of course this is not the same as working on the engine!! Anyway, if I do the job it won't be much more effort (by the time I find out) to drop the engine out if I find that is needed?!

So, I was not looking for step by step guidance, more the case of "hot tips" for what goes wrong and what else can be done (e.g. changing bolts) while it is in bits - I am used to the fact that it is much easier to take something, anything, apart than it is to put it back together again correctly!

I originally got the bike for the simplicity of it, including the engine; I wanted something simple after multi-cylinder bikes with fuel injection - on the downside it is proving to have many more issues than any bikes I have owned since year dot which kind of negates the original simplicity theory!!!!!

I am still up for any more ideas before I take the next step; fortunately my wife has a bike that does not have problems and I can always ride that!!

Dave

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Dave

Gentlemen,

Replacing the cylinder gaskets is about *** on the scale of *****, but: no guts no glory as they say in the US.
First step, determine indeed where the leakage comes from. As earlier said, clean the engine on the outside thoroughly, then spray talcumpowder on all surfaces. Drive a bit, you'll see where the oil comes from.
Then, buy yourself a manual. Indispensable!
Then, having determined the origin of the leakage, you can do a precision attack on the problem. If it's just R/H or L/H cover, it's an easy trip home: * on *****. On the L/H cover, besides the gasket, also replace the two O-rings.

If it's cilinder base of head gasket, it gets a bit more challenging. See below for some tips.

Specific questions (I am thinking of doing this with the engine still in the frame):-
++ Yes, you can do this with the engine in the frame. Take care about the one Allen bolt in the valve cover that is hidden between the upper frame - engine connection bracket.
1. What to look out for in both the dis-assembly and re-assembly? e.g. getting the cylinder back over the piston rings when putting it back on the bike.
++ That's a bit tricky, be careful, use the tapered edge at the cilinder base, and lubricate everything liberally. If you have to force anything you are doing it wrong.
2. Should anything else be replaced while the engine is opened up? (bolts?). ++ No, just gaskets: cilinder base gasket AND O-ring, cilinder head gasket, the two small oil seals in the oil channel. Exhaust sealing rings: depends on their state. Carb connection to cil head: no, just seal the connection with some of the same fluid gasket you use for the valve cover.
Use ONLY Yamaha original gaskets. The rest is a waste of money, you'll be repeating the procedure in a few months time. Beleive me, I know.
3. Anything "awkward" about putting the timing back in place? In fact, should the bike engine be stripped with the timing in a particular "position"?
++ Putting timing back in place: not difficult. The sequence is: install cil head, install chain guide, install camshaft, adjust timing, fix the two gearwheel to camshaft bolts with locktite. Put piston in Top Dead Center, end of compression (the cam lobes point down towards crankshaft. This way you'll have no problem installing the valve cover. This also applies to removing the cover.
Only when the valve cover has been installed and all bolts tightened you install the chain tensioner.
The valve cover is installed with fluid gasket. This must dry at least 24 hrs before you start the engine.
4. Should the engine bolts be "loctited" on re-assembly or not? ++ No. The engine - to frame bolts must be torqued correctly, or, be very tight, as the engine is a structural part of the frame.

Some more advice:
- Work very clean
- Clean the inside of the cil head and the piston crown from carbon deposits with a wire brush on an electric drill
- Before moving from one step to another, or fastening a gasket, check that you did not forget anything, like a small seal, small bushes, etc. They are there for a reason!
- Install a fresh spark plug while you're there
- Leave the piston on, if not, you MUST use new clips that keep the piston pin in place
- Take care that nothing falls into the crankcase. Best to cover with a rag
- Make a carton with holes in the pattern of the bolt holes of the valve cover, put the bolts in the carton upon disassembly. This saves hours finding out which length of bolt should go where

That should see you through..
Auke

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Auke
http://aukemarieke.blogspot.com

Thanks a million Aukeboss!

That is really good information; as I mentioned, I have a cd manual with torque values, sequence of working etc etc but it is those tips of yours that make the difference - I can see exactly what you are saying about the relationship of TDC to the ease of removing/fitting the cyl head cover for example.

I have not done the talc powder test - I assumed it would blow off in the wind and the bike does not appear to leak at tick-over revs. But I'll give it a go for the experience!!

I can see me doing this job - my problem has been that I got the bike to ride (obviously) and it has been a case of one thing after another since then. This is just the latest in a series of problems with this particular bike and I have been wondering if it is a "Friday afternoon" case or if it has been run-in wrongly in the past or whatever!! I have also been starting to double-guess what is the next thing to go wrong!!

Reading online about the "instant gasket" stuff a bit more, there seems to be a few different types around - is there one that can be spread onto an existing genuine gasket insitu to help in sealing the engine? - just a thought.

By the way, any theories about why gaskets blow "prematurely"?

Still up for any more guidance/thoughts etc on this topic - Pol how are you getting on?


Dave

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Dave

Well, at least it is confirmed; the oil is leaking from the gasket between the crankcase and the cylinder at the back of the engine only (nothing showing at the front of the engine or on the crankcase covers) and on the left hand side - from there it spreads and blows around to look as if it is coming from elsewhere as well.

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Dave

I have studied the manual for this job while staring at the engine in order to spot any issues.

The one thing that has me beat at present is that I can see how to get spanners onto all of the external nuts/bolts while dismantling the engine but I can't see how to get my torque wrench back in there when re-assembling the engine. The torque wrench is bigger than the end of a spanner and there is very little clearance for the cylinder bolts on the right hand side and the cyl head bolts at the front and back of the engine. In the former case it is an issue of "headroom" clearance to the cylinder itself and for the latter, the bolts appear to be very tight up against the cylinder and for headroom.

Does anyone know of an alternative to the usual "click type" torque wrench or what other technique will get the bolts/nuts to the correct torque setting? (Does Yamaha have yet another special tool???!!).

Cheers,

Dave
ps The chain tensioner may have a similar issue with clearance for tightening it vis a vis the adjacent oil tank (but in the worst case the oil tank could be removed).

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Dave

In my previous life as an electro mechanical engineer, we had to set everything to various torques, stretch measurements etc. You need a newton gauge, it looks a bit like a fishermans scale, but graduated in newtons. Simple maths from the measured length of the spanner and careful tightening should enable you to get it right.

Hi Leigh,
That will be a spring balance then, along these lines:-

http://search.ebay.co.uk/search/sear...ance&category0=


I see what you are saying; basically use the balance to apply the force x the lever arm of the spanner (at right angle) = torque.

Cheers,

Dave

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Dave