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ttr250ug · Newbie

Clattering noise after taking out and replacing cam chain tensioner

TTRfan · Super Guru

Could the timing chain have jumped some teeth in the process? I can't think what else would cause the clatter as you haven't disturbed anything else confuse

I think it may be worth getting the cam cover off to check - see http://www.ttr250.com/Removing_Cylinder_Head/TTR_head_removal.htm for details and what the timing marks should look like.

Any questions or problems just ask again.

Brian

ttr250ug · Newbie

Thanks Brian, although my knowledge of engines is very elementary, that issue did cross my mind as when replacing the cam chain tensioner as the first time I was using a long screw driver to hold spring, which I had trouble taking out as too long which prevented me from allowing the screw driver to gently rotate allowing the tensioner to smoothly extend, but rather just "ping" out. A local Ugandan mechanic has since made me an excellent tool by flattening the head of a nail and bending it in 90 degrees to work as a handle. Which has worked lovely on the attempts I made after at replacing.

So just to be clear I need to take cam cover off, and find TDC and if the lobes/marking do not look the same as in your photo, then that will be the issue?

What would i need to do then? Break the chain?

Thanks very much in advance.

TT-R250M · Super Guru

ttr250ug wrote:

So just to be clear I need to take cam cover off, and find TDC and if the lobes/marking do not look the same as in your photo, then that will be the issue?

What would i need to do then? Break the chain?

Thanks very much in advance.

If the cam marks do not align as pictured in Brian's thread, then YES you will have an issue.

If it is not the same as in Brian's thread -You will then need to replace the timing/cam chain as it will have been damaged/stretched during the timing/cam chain slip. It would be advisable to check your timing/cam chain guides for excessive wear, the cam sprockets/cogs for excessive wear, and the top bump stop as well. To do this you will need to remove the clutch cover, clutch plates, cylinder head cover, oil pump drive gear etc.

Here is a thread from when I did this, just avoid taking the cylinder head off (if you can) as it is not needed unless replacing cam chain guides or piston and rings.

A picture of the clutch cover...

Now with the RH brake pedal, RH footrest cover, and the clutch cover removed with a 5mm allen key on a ratchet with extention bar with a 5mm socket over the allen key.

Next stage- take the clutch plates out by removing the five Philips head bolts making sure they unbolt evenly...

Note: Do not take the bolts out one at a time or the springs may need replacing afterwards.

Note: Be careful not to loose the small ball bearing located inside the clutch drive shaft.

Now on with my ''special'' clutch holding tool...(looks pretty damn good with the engine stand smile ).

I made this tool so I could hold the motor from turning while removing the clutch boss nut (pictured centre of clutch boss)...

Note : Anyone interested in seeing more on the ''special'' tools & how I made them click here... Homemade ''Special'' tools

First job is flaten the locking washer the nut. I did this with a medium flathead screwdriver, (starting off with a small one) and a hammer. I then removed the clutch boss nut with a 27mm socket & breaker bar.

I like to use the shock treatment (hammer onto breaker bar effect) myself to crack the nut as this can be a little tricky to remove.

Once the clutch boss nut was removed it was time for my other ''special'' tool for removing the clutch boss.

Very simple just M6 bolts,an old holden radiator fan cut down & a rear ford diff bolt with a nut welded to the old fan. It makes short work of removing the clutch boss & only needed to re-screw the M6 bolts once to get it all the way off.

Now that the clutch boss is off the clutch basket just slides off....

It is now time to remove the oil pump drive sprocket & old cam chain guide.

Note: you can remove the large crankshaft drive shaft nut (pictured below) and remove the cog/sprocket instead of removing the oil pump but I found this method was easier and was a good chance to clean the oil pump.

I then lined it up to TDC making sure that the cam chain was held up with some tension by hand so as not to get it caught....

Now that I have room I took the opportunity to clean the oil pump (not that this was needed). Four big Philips head screws hold it on (as seen above).. On this occasion one was tight so I used & pair of vice grips over the screwdriver to loosen it (it worked a treat).

The oil pump filter should be checked as it's easy removed and not a hard job...

To re-assemble the oil pump is a little tricky...

First coat the inside with fresh oil after cleaning...

You line up the little pin (in the shaft) sideways evenly (as shown in pic below) & then line up the marks on the oil pump (as shown in pic below)...

Important info: All drive sprockets & moving parts, clutch plates ,bearings, etc. are oiled with engine oil or assembly lube.

After fitting the pre-oiled cam chain ,oil pump, oil pump drive gear (fitted with new circlip) & (cam chain guide-with Loctite) this is what it looked like...

Now it was ready to oil & fit the clutch basket. My clutch holding tool came in handy for tightening the clutch boss nut.

Don't forget to bend the ''new'' locking tab over when clutch boss nut is tight.
Never re-use a locking tab that has been bent.

When fitting the clutch plates make sure that the little ball bearing is fitted correctly inside the clutch drive shaft...

Now to adjust the clutch.

First push the actuator lever in & align it on the mark as shown in the pic below...

Now tighten the locking nut adjuster.To do this screw it all the way in until it lightly seats.

Then back it out roughly a little less than 1/4 of a turn until there is ''standard'' play & tighten locking nut....

The manual says to fit the clutch cover now but I like to be able to see the cam chain.

Time to install piston pin. First a plastic bag was used to stop anything falling into the motor. It was quite easy to install the pin & didn't need to freeze it but I did put it in the freezer for a little. It was a nice fit & squeezed right on in with the help of some oil. Fitting the piston pin circlips can be tricky & requires patience.

I also put a smear of gasket goo around the dowels.

Time to check ring gaps and install the cylinder....

Note: If you are only going 1~2mm oversize piston filing the ring gaps should not be needed.

This is the 74mm Wizeco piston fitted with ring marks up, arrow to the front & ring gaps checked & oiled before fitting...

Install cam chain guide.

At this stage it is ready to install the head but just to be sure I put a little gasket goo around the dowels again (pictured above).

Head went on & in with the white packing foam. This was to prevent anything from falling into the motor. I also installed the spark plug to stop anything getting into the cylinder. A piece of wire was used to hold the cam chain from getting caught with the camshafts removed...

When removing camshaft caps special care is needed. The handle end of a screwdriver tapping either side loosens them up. Then I used a rag under a screwdriver (so as not to scratch the mating surface) to remove the caps.

The head bolts & retaining nuts were oiled & torqued to spec.

On a side note: Something interesting I found is that when the main head bolts are at spec, the motor starts to move on stand so it is easy to judge the spec wink

Oil camshaft journals & install caps.

Now time to check & align the rotor to TDC... (use a 14mm socket on the rotor bolt to turn motor).

Edited: Special care is needed to insure that the chain does not get caught while lining top dead centre up. To do this pull upwards on the chain keeping the tension on the chain while turning motor to TDC (top dead centre)

Install cam shaft sprockets & cam chain beginning with the right side (exhaust) making sure that the camshaft lobes are facing away from each other like the pic below..

Line it up as shown in pic below install one camshaft sprocket bolt finger tight to hold in place. Now do the same with the other until it looks like this..

IMPORTANT: Take note of how the E on the camshafts sit & all marks shown below

The manual is not very helpful for this part so line all marks as shown below...

I realized by looking at this thread properly that I had missed a detail out for tightening cam sprocket bolts. This is to stop it putting too much pressure on the chain when tightening.

The drawing on the picture below represents a screwdriver ( a little :)

Note: If using this method be careful not to damage anything!

Time to install the manual cam chain adjuster. This is a bit tricky & I had to double checked it (ten times :). When you set the tension you screw it in finger tight & measure how much play is in the chain when pushed down. The play has to be roughly 2-5mm. Do not over-tighten or wear & damage will be the result.

I used Loctite on the cam sprocket bolts as I don't want them working their way loose.

Now I fitted the head cover & clutch cover. I like to use a high temp silicone on the half moon shapes (only the bottom surface of the gasket)...

You are suppose to do the oil filter in all of that but I can't yet as my cover is at the paint shop.

Edited: This was fitting the oil filter...

This was when I installed the K&N oil filter...

Quite easy just unbolt the three 5mm Allen keys making sure the three O-rings don't get lost.

Take out the old filter & end rubbers. Install new filter (with the rubbers).

Then install the cover making sure the O-rings are installed properly.

Job done~

Jarrah.