Reviving A -99 Tdm 850

Looking good !

Kepp up the good work

Intake manifolds

As it was mentioned earlier, the center-center distances for the carbs are the same on the 900 and. This is good because the carbs and air filter can bee fitted without modifications.
I also think that the distance between cylinders is the same, since the 900 barrels should fit the 850 engine. The crankshaft has a different article number in the parts catalog, but is weary similar on later 850 and 900 engines. The balancer shafts, bearings and some other parts near the shaft are the same.

The intake manifolds.
The 850 intake manifolds are on the left, and the 900 on the right. One can see that the 900 ones are shorter and that the bolt pattern is a little different. Also the diameter of the 900 "carbs" that goes into the rubber boot is bigger.


My plan is to make a adapter from the shorter 900 manifolds to the 850 rubber boots. I should also get the right "height" of the inlet manifold by doing so.
The 900 inlet manifold on the left top in the picture. Then the aluminum rod for the adapters. And the original 850 inlet.


The ready adapters, it took some hours. The inside of the adapters has a rounded conical shape, since the 900 inlet manifolds has a somewhat bigger diameter.


Fits perfect


With the 850 rubber boot it has the same height as the 850 inlet. The 850 original inlet on the left.


Between the boots there is enough space for a vacuum tube connection. It will be used for synchronizing the cylinders.
The connection is made of copper car brake tube. It is pressed down in a tight fitting hole and glued.


Since the 900 inlets does not have a cylindrical shape, some grinding was necessary. I used a dremel like tool to remove some of the vulcanised rubber from the 900 inlet manifold. Metal was exposed in some places.




By doing so the cross section area was not constant trough the inlet manifold. It increased when near the 900 inlet and aluminium adapter mating. It is not good, but I do not know if it is critical for this engine. There are no sharp edges tho.
It is better to make the inner diameter of the aluminium adapter cylindrical, and then grind it to fit the shape of the 900 inlet.

Very nice

Thank you

Cooling system, and pre startup stuff

With the new inlets, a startup was closing in. But before the startup, the cooling system needed to be in order.

I now realized that my new engine bracket (the upper piece I welded to the frame) was in the way for the coolant hose.


But no problems. I bought some house pieces from a scrapyard,


And made a piece that fits (above) instead of using the original (below). It looks quite terrible. The outlet from the thermostat housing is straight and points directly into the welded bracket. I am thinking of trying with the 3VD thermostat housing, the outlet from it is pointed slightly forward, which could reduce the number of twist.
So if someone has one to sel, I am interested.


Here is the radiator installed, and the twisty coolant hose with it. Notice the idle adjusting screw moved to its new position on the bracket.


The vacuum hoses for carb balancing are routed to this side for easy access.


Other side of the bike


Then installing of the carbs. Some wires and hoses needed to be rerouted due to the same bracket. Choke wire was a pain.
Here is a pic of the oil fill hose.


And all the tubes and stuff surrounding the carbs. Here I also discovered that coolant is circulating into the carbs and heating them :/


Then on with the air filter box.


The spark plug caps did not fit, the spark plugs are "deeper" in the valve cover than on the 850. But I could make it fit by removing the upper rubber seal. Not optimal, but now I wanted to get the beast going.

Does the 900 have ignition coils similar to the 850? I have read that one can fit spark plug caps that contain the ignition coils from Yamaha R1. Has anyone tried that? What would be the pros and cons?

Then I started to fiddle with the ignition covers. The bolt patterns are identical, the same gasket can be used on the 850 and 900 engines.
I wanted the 850 cover, because the gear lever is bolted to it, and the 850 cover gives the correct distance between the lever and footpeg. On the 900 footpeg and gear lever are further back, and therefore the hole in the generator castings is further back.
The 900 generator to the left, and 850 to the right. It is also quite easy to figure out the electrics. 3 cables from the generator winding. And 2 from the pickup coil.


One difference that I noticed, was that the 900 engine has a bigger generator, both windings and the rotor. I wanted to use the bigger generator, but the windings are mounted on different depths in the cover. The 900 winding can mot be mounted on the 850 cover, and then on the 900 engine with 900 rotor.

The winding. The bigger 900 winding on the left.


Measuring the mounting depth in the cover. The 850 cover is more "shallow" and will not allow the 900 winding to be fitted. Winding will interfere with the rotor.


In the end I used the 850 cover with the 850 windings, but with the 900 rotor. Both 850 and 900 rotors has the same number of magnetic poles, and both winding has the same number of "slots". So it should be no problems. Since I am using the 850 cover and windings the connections to the bikes harness are no problems.

Then fit the exhaust. The 850 header pipe I had did fit to the cylinders, but the bolts were too short. And it was interfering with the bottom off the engine.


I fitted new longer bolts in the cylinder head. I used stainless threaded rod that i cut in wanted lengths. One can hop that they will not rust.
Then bend the pipes so some clearance can be achieved. These pipes are really hard to bend without damaging them.
I have some clearance, but it is not looking good.


Then fill oil, fill coolant, charge battery (a new battery was fitted while the engine was out).

Click the starter, but it wont turn, not even click. Only lighting some warning light.

Next post will be about ignition and neutral light sensor. And removing the rotor.

Edited by anda3243, 08 January 2012 - 02:34 am.

Noice progress, starting to look loike a boike now.

Have you had the boike running with that hacked air filter before the enjn swap? I remember someone trying to modify an airbox before and it made the boike run loike a dawg.

Thank you

Yes the bike has been running with this air filter mod.
I started it up before the teardown, and it run ok. And it runs great now.

Anda brilliant write up,,, to answer your question re coils,,, i fitted 850 coils to my 900 without any issues at all,,, heres a little more info,
http://www.carpe-tdm...showtopic=15971 sure you have it sorted anyway.

Thank you for the post. I read the tread you posted. And also found this thread: http://www.carpe-tdm...p?showtopic=268
and breafly read all threads linked from it

The conclusions I can draw are:
Problems with coils and HT leads arcing and shorting to the frame are common.
It can be prevented by changing the HT leads when damaged or aged and insulating the conections to the coil and spark plug.
This is probably affecting many bikes, by decreasing the performance. But not fixed until the bike realy will not run.
The problems are most common on the 850 mk2 and 900.
The 850 mk2 coils are easier to seal of preventing moist getting into them.
The 850 mk1 uses a single coil, this can be done because of the 180 deg ignition sequence.


I wonder, has any of the 900 riders tried using ignition coils/spark plugs from a Yamaha R1 or similar?
The spark plug cap and the ignition coil is the same part. It would eliminate the need of HT leads. And most moisture should be heated away by the engine.

This link I have posted before, he seems to be using a coil like this.
https://picasaweb.go...029494112618466
https://picasaweb.go...ZProjektinKuvat

I want to change the spark plug caps before the 2012 season. Should I try the R1 ones?

The coils on Plugs is a great idea as it will obviously get rid of the ht leads. Got to be worth looking in to

Nice work!

Tempted to go an buy some used wans, would also need the wiring loom or a suitable connector plug. Think I'd go visit my local secondhand R1 cap coil shop and see if they would fit first tho.

This is quiet a common mod for the older Kawasaki's.

They were plagued with coil probs. Used to use Honda CBR 600 / 900 bits.

Lots of info on their ZZR club website.

Mik

Let me know if you find something that fits.

I consulted the workshop manual and found this:
For the 850 the primary winding resistance on the ignition coil (between the low voltage pins) should be between 3,1 to 4,6 ohm.
The secondary winding resistance on the ignition coil (between the HT cable connection and one of the low voltage pins) 10,4 to 15,6 Kohm.
The resistance in the spark plug cap should be 10 Kohm.
All measured at room temperature.
I assume the same specs for the 900 since the coils can be changed between the bikes.

Then for a combined plug cap/coil the primary winding resistance should be the same 3,1 to 4,6 ohm.
And for the secondary winding, the resistance should be higher, both winding and cap resistance. Aprox 20 to 25 Kohm.

On second thought the secondary winding resistance should not matter. Only the primary winding resistance.

Yamaha YZF R1 2007 -> the primary winding resistance is 0,85 to 1,15 ohm.
Yamaha YZF R1 2004 -> the primary winding resistance is 1,19 to 1,61 ohm.

I will read some in the ZZR website

http://motorcyclepro...2-p-220346.html

Fifty quid a throw is a bit steep, but I like the concept.

Yes but that compares well with the OEM plug cap price, second hand price of a full set (4) is that.

Re: primary resistance, just curious to know. Would the lower primary resistance of the R1 coil cap suggest that a different spark plug would be needed ? Or is the lower resistance a result of the smaller coil compared to the 850 coil ? Or summat else ?

Just thinking that if it's because the coil is smaller then the lower resistance reading wouldn't matter.

So far I understand.
I think that the lower resistance will draw a bigger current. Wich could give a bigger spark. But this could also reduce the lifetime of the coil.
I think that the best is to find coils with the same primary winding resistance as original.

If a different spark plug is needed? I do not know. A different outer geometry of the spark plugs can be used to make the coils/caps fit.

The YZF250 and the YZFR6 also use a coil cap but I don't have any specs for them.

Hmmmm, just found some info regarding the YZF-R6 COP's (Coil On Plug) and it looks like you are correct about a lower resistance producing a larger spark.

Be very careful with the COPs - the '99-05 models (and '06+ 'S' models) were CDI, and use low-resistance (~ 0.2-0.3 ohm) coils. The '06+ are TCI like the FZRs, and have high resistance (~ 2 ohm) coils. The risk with using the wrong coil is too low resistance = too high current = dead ignitor box.

Taken from here:- http://www.fzrarchiv...php?t45254.html

Thats great.

I have not read into it that much. Maybe tomorrow. Just hope that there are coils with 3 to 4 ohm resistance on the primary winding.