Rich and rough engine woes -- 2001 (03 US) Gen 1

[Fred W]

OK, I see why we are in this quandary. I didn't realize the chain can't be moved on the exhaust sprocket without yanking out the cam.

So what needs to happen is to remove the exhaust cam (again) and make sure that you only allow the chain to move a single tooth (either forward or backward, doesn't matter). That way when you re-assemble the whole thing and get the chain where it needs to go on the intake and crank sprocket, the crank timing mark will be 1/2 way between the two pictures that you've shown before when the cams were in the correct position.

Maybe do it this way:

Ty-wrap the chain to the exhaust sprocket now.

Release the CCT and pull the caps off the exhaust cam.

Once you have it free and with enough slack, cut the ty-wrap, carefully move the chain over one tooth (either way) and then tywrap it again so it doesn't move while re-installing the cam.

Once the exhaust cam is back in, then go through all the steps that you seem pretty adept at by now to get the two cams in sync with each other and then finally get the chain onto the crank sprocket.

 

[wmadoty]

..."There is no room to get the chain off the teeth of the cam sprocket with it in place, which makes doing what Fred has suggested unfeasible."

Sath, could this thought process be why your are still off by at least a half a tooth? I do not think you will ever get this engine back in time by moving the chain at the crank gear. You will have to secure the chain at the crank and move the chain one tooth at the cam.

What Fred has instructed you to do is feasible if you move the slack around the right way. You have enough slack but it is going to be tight. If it was loose and easy to move around the cam gears then I would be more inclined to think the chain was badly worn. One tooth on the cam would be a half tooth on the crank. A tooth on the crank will be two teeth on the cam.

In addition, the picture of your cam sprockets above, show that some of the teeth of the gear come to a sharp point. If that is the way it really looks then you have very severe wear on the cam sprocket. All the teeth should look the same and should not be work to a sharp point.

Good luck getting this back together.

 

[Donal]

Looking at Howie's pics again, it seems to me there is another option. Release and remove the lower camshaft-sprocket retaining bolts, just leaving the upper (accessible) bolt in place on both camshafts.

Ensure the crankshaft is lined up correctly.

Get both camshafts lined up correctly.

Remove both the upper camshaft-sprocket retaining bolts.

Fit the chain.

Slip the chain on the crank sprocket until the camshaft-sprocket retaining holes line up.

I may be losing my (slightly tenuous) hold on reality but..............

 

[sath182]

I took a series of pictures each an example of one tooth off. Very carefully, one tooth off. All pictures are with the crank at TDC.

These next three are with the crank retarded one tooth, retensioned and spun over.







The cams are still in time with each other

I then retarded the intake by one tooth, retensioned and spun over.







As you can see they are no longer in time. The difference is quite obvious. And the engine still turns freely.

I then re-timed the engine to what I've been getting as the closest to true, secured the chain, loosened the CCT, then advanced the intake cam alone using a mallet and dowel. This is where that left me;



And for reference, here is what my CLOSEST timing looks like.





All of the one tooth off pics are noticeably higher or lower than these positions, that's why I think I've got to eliminate potentially worn parts to fix it. We'll know when the chain gets here if it helps.

Edit: You know, looking at Howie's pictures again, his cams aren't perfectly straight either. In fact, the position of his exhaust cam looks pretty close to mine. At least the new chain is comparatively cheap.

 

[Fred W]

If those last two pictures are done with the crankshaft at the T - mark, then that is what you are looking for. That is good enough.

 

[sath182]

Since I've already ordered I'll wait on the chain to arrive. No difference and I'll button it up and send the chain back/sell it on eBay. I already have the o-rings and side cover gasket so I could slam it together right now. I did order a new valve cover gasket though. This one is original and doesn't have all the connecting bits for the inner sections.

 

[Donal]

Just for future reference; if you have time could you count the number of chain links between Inlet & Exhaust and between Exhaust & Crank.

Looking at Howie's pics

It looks like there are eight 'links' between the top tooth on the Inlet Camshaft Sprocket and the corresponding tooth on the Exhaust Camshaft Sprocket.

If we know the number of links between the Exhaust Camshaft Sprocket and The Crank Sprocket then the chain can be pre-marked with a paint stick (or something similar) and could make installation easier.

 

[Donal]

In one of your earlier posts you were a bit concerned about the rear suspension relay arm. Now that you are a member of the FJClub you can get a fully reconditioned arm (new bearings collars, used relay arm) for £200 with a £100 deposit repayable when you return your old arm. Of course you can also buy all the individual parts from them as well. Exchange arm here individual parts here

 

[sath182]

My parts finally came in this week. I couldn't get the pickup rotor off the crank so I said screw it and put it all back together. I haven't taken it for a ride yet, but the idle now adjusts how its supposed to. I can smoothly increase it right through the previous dead zone. The exhaust also isn't stinking so terribly of fuel. I will need to take it to the tuner soon to set the CO and fully balance the engine.

I can't wait to get out and ride. I thought the engine was strong before. I wonder how it'll feel now!

And Donal, I have the bearings seals and collars for the top and bottom of the link arm. I'll keep in touch for when we can get it done.

 

[kamal]

Good to hear that you seem to have it sorted.

BTW. My mum, 92 this year, is from Harrogate. I remember staying with relatives in Blubberhouses - as kids that always made us giggle!

Al.

 

[Donal]

And Donal, I have the bearings seals and collars for the top and bottom of the link arm. I'll keep in touch for when we can get it done.

Won't be around for a few weeks, heading over to the Isle of Man next week.....................

 

[sath182]

Of course, Donal. I'm gonna be recording it all. I just hope they broadcast the supertwins class this year. Now that John McGuinness is contesting it, I expect they will.

I'm getting at least a small ride tomorrow morning. Maybe I'll have no choice but to drag it out longer.