38 replies to this topic

[viper_biker]

Story so far, bike off the road for valve clearance check , had to replace some inlet shims so bike is at TDC and rear cam shaft out. The cam chain sprockets are still fitted to the cam shaft itself and it's a complete nightmare trying to re-sit the chaft in the correct position. I have not slackened the tensioner cap, spring etc. Does this need to come out completely before the shafts will re-sit or slackened enough to allow it to be seated?

Question 2.

My air-box doesn't seat correctly onto the carbs. Firstly, the clamp it too big that when it's fully tightened it still turns freely on the rubber spout, and secondly, the air-box says 3VD on the snorkel part. Does anyone have a pic of a standard 4TX air-box from 96-97 as I don't know if the vary from each model. I attributing my crap mpg to this and having HUGE jets fitted (now got 155's in there to see how I go with them).

Thanks for the help folks.

Edited by viper_biker, 18 March 2007 - 06:28 pm.

[ChrisG]

It's a ratchet so I don't think you can slacken it without taking it out. It comes out quite easily on 2 bolts but I had to slacken one of the engine mounting brackets to get it right out.

[robelst]

I am not sure if this is the ultimate / approved method but when I replaced the cam-chain I set the tensioner at at "lowest" setting and turned it in loosely, just to get a little bit of "pre-load" on the chain. I had one of the top cogwheels off to make it easier to navigate the chain around. If you leave the tensioner out completely I found the chain almost dropping off at the bottom-crankshaft cogwheel, making the chain jump out of sync by almost just looking at it . Other than that it's a quite straightforward operation: Cylinder 1 in TDC (check what side the cams are pointing at, see Haynes) and align the top-cogwheel marks pointing to each other, parallel with the edge of cylinder-head top. If all is in place just turn the crankshaft manually to settle the tensioner at its initial setting (you should hear a few clicks while doing this).
I can't 100% guarantee this method but it worked for me, and it's already a few k-miles ago.
Here are some adventures of mine, with pictures: http://www.carpe-tdm...?showtopic=2911

Good luck!

Edited by robelst, 17 March 2007 - 07:31 pm.

[Stink-Foot]

I found it easier to take the sprocket(s) off the cam shafts and install them once the cams are at correct position. Chain tensioner should be pushed completely in with the spring removed.
Cam shafts have holes in them, so you can use screwdrivers or something similar to hold them in the correct position. A few extra hands make it easier but it can definitely be done alone. Once the sprocket bolts are fastened, fit the tensioner spring and bolt before letting go of the cam shafts.

[jht]

Unbolt RH engine mount

Remove tensioner spring cap, and spring

Remove tensioner assembly

Do your cam chain refit fiddling thing to cams

Refit tensioner


Then refit spring and cap

Job done

Dont try poncing around without taking out the spring from tensioner, as tensioner will fully extend out once u have loosed cams to do shims

Once it out you can reset it all way in before refitting, then when you fit spring tension taken up

Clear as mud??

[Stink-Foot]

Unbolt RH engine mount

Remove tensioner spring cap, and spring

Remove tensioner assembly

Do your cam chain refit fiddling thing to cams

Refit tensioner
Then refit spring and cap

Actually it isn't necessary to remove the engine mount. It's a bit fiddly but you can get the tensioner out with it in place.

Also I would fit the tensioner (without spring of course) before refitting chain and sprockets, that way you can just push it to tighten the chain. No need to hold things in place while refitting the tensioner.

[robelst]

Actually it isn't necessary to remove the engine mount. It's a bit fiddly but you can get the tensioner out with it in place.

Also I would fit the tensioner (without spring of course) before refitting chain and sprockets, that way you can just push it to tighten the chain. No need to hold things in place while refitting the tensioner.

I am not sure if you are supposed to push the tensioner manually, that's where the spring is for once the whole thing is re-assembled (turn the engine manually to make that all happen). I suppose you could overtighten the chain bu doing so? The only reason you'd want to push it is when the spring and/or chain is worn to such an extent that the tensioner does not go all the way out to the last "click". But if this is the case and you have the whole thing opened up you might as well replace all that at the same time, unless you have too much time on your hands and don't mind digging it all up again after a few more thousand miles All you need to do is take the oil-pumps off to get at the chain's bottom sprocket but that is not half as daunting as it may sound. You will need new circlips and oil-pump cover gasket (cost around £2.. well, plus a new chain of course, they are around £50 (DID/ID from Wemoto)).


BTW: Simple-minded as I am I used a few tie wraps through the eyes of the sprocket over the chain to keep all in place while farting around with the tensioner. Not very professional maybe but I found it quite handy. And as long as you don't forget to take them off once all it tightend up it can't do any damage

[dandywarhol]

.........it's a different tensioner on the 900 ET.

..........and to add to that wonderful piece of prose - make sure the engine is on TDC LEFT CYLINDER FIRING otherwise the fuckin' rear cam jumps 3 teeth found that one out in CZ last year - had to strip the top end in Granny Zloty's garden

[dapleb]

had to strip the top end in Granny Zloty's garden

and use the poor ole dolls favourite washin ooop bowl to drain the coolant.....wee bassad.

[viper_biker]

Just to add to the new question, here are 2 pics of what I mean.

The 3VD on the snorkel,



The rubbers don't fit on the right way no matter how much heat I added, but it fits upside down, but I don't want to do that.

[aytcat1]

I cant undestand why you used heat on them unless to soften them try putting something slippery on the rubber like wd40 or washing up liquid should go on then but its a tight fit has to be start one side and work you way round

[dapleb]

I would have thought the snorkoo is exactly the same for 3VD and 4TX, just one of the many interchangeable parts? They just had a 3VD in the bin when your boike was made.

There are a few threads around where peeps have replaced them thur rubber poipes cos they get brittle and wont clamp doon. Are you sayin it wont go over tut carb or that it will but you cant clampett?

[viper_biker]

UPDATE - Engine is sorted, cams are fitted and timing is sweet. Re-built forks are back on, incl rads, carbs, thermostst etc etc Today will be new pads all round, new fluid, calipers stripped and cleaned, tank and bodywork fitted and fresh oil, oil filter and airfilter and coolant than off to test the hard work.

snorkel is the same

You need new airbox to carb rubbers - mine did exaclty the same thing.
They go hard and shrink & you can't get them onto the carb bell mouth.
They are about £20 /pair from your local stealer.

Am I right in saying the part number is 4TX-1453-40?

[viper_biker]

So there I was, engine back together, new plugs, oil and coolant in, exhasust back on in anticipation of the roar. The roar was more like a 60-a-day's bad cough. After the bike kicked in it wouldn't idle, didn't like the choke and could only start it with a little throttle. Turned the idle cable up a bit and she would tick over, but not like she used to, so out came the coolant, off comes the rads and the cam cover again. As far as I was aware, it did everything the Haynes and service manual told me. Both dotd on the came were pointing up,



But the bike was firing wrong like this. When the bike is set at TDC inlet on cylinder one is almost at full stroke and C2 exhaust is the next to follow,



Now this is where it goes wrong (I think). the inlet on C2 and exhaust on C1 are firing at the same time,



The timing marks on the end of the cams are correct too,



Can anyone point out to me where I've gone wrong? I'm glad I've done this now as Id be in a right pickle if my trip to Spain was a lot closer. I want to take the TDM but if all ales fails, I'll take a VFR. Thanks folks.

[stormy]

when you say the no.1 cylinder is one TDC, is it on the correct stroke? i.e. on the compression stroke, piston at the top (take plug out to check, and with ALL the no.1 cylinder cam lobes pointing away from the valves?

Also, with regards the markings on the cam sprockets, I think I read in the manual to ensure that the "inlet I" mark isn´t confused with the "H" mark.

Might be a silly point, but I did this once on my TRX ........ you never know.

mike

Edited by stormy, 18 March 2007 - 06:26 pm.

[viper_biker]

when you say the no.1 cylinder is one TDC, is it on the correct stroke? i.e. on the compression stroke, piston at the top (take plug out to check, and with ALL the no.1 cylinder cam lobes pointing away from the valves?

Might be a stupid point, but I did this once on my TRX ........ you never know.

mike

I'll go check. When I mean TDC I mean that behind timing cap it's at the 'T' mark.

EDIT - If anyone who know's a bit about this can you add me to your MSN and we can chat as I do it. Get me at gjanders2001(@)hotmail.com

Edited by viper_biker, 18 March 2007 - 06:28 pm.

[dandywarhol]

Stormy's right - it might be on TDC in the cover marks but it HAS to be on cylinder no.1 (left sitting on the bike) and if I remember rightly with the cam lobes pointing exhaust to the front and inlet towards the rear - GG/Dapleb help me here..........