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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> valves
Post Info TOPIC: valves
JOHNYBOY


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valves
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just reconning a cyl head for my oe had the seats recut lapped valves in tested with mechanics blue to get stem seals & shim up wish i could put photos on but i struggle they ought to be an easier way to do this for us old members 

come on brian while your bored  eating pasties have a look



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JOHNYBOY


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just had a look at the graph for shimming what size shim to use i cannot understand it can anyone explain please john

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TTRfan


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What are the clearances on the valves out of spec John? In mm pleasewink



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TTRfan


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JOHNYBOY wrote:

just reconning a cyl head for my oe had the seats recut lapped valves in tested with mechanics blue to get stem seals & shim up wish i could put photos on but i struggle they ought to be an easier way to do this for us old members 

come on brian while your bored  eating pasties have a look

No pasties for a week John - I am getting withdrawal symptoms disbelief 

Regarding posting photos, I used to load all my photos from an online photo store but find it easier now to just drag photos across from my photo viewer. This may be easier for you John if you aren't a confident IT user.

I use FastStone Image Viewer to view and edit my photos - a free download is available here - but the following should work with other photo viewers - hopefully,,,

First open a new post screen in the forum where you want to add a photo.  Also open your photo viewer. Minimise them and re-size to fit the screen with both showing. Then follow instructions as below:

Photo add1.jpg

Photo add2.jpg

Photo add3.jpg

Photo add4.jpg

Photo add5.jpg

 

If anything doesn't make sense just ask again wink

Brian



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ttr steve


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Hi John

Before you take anything apart, measure the clearances you have in the exhaust and intake between the cam lobes and tappet and make a note.

Then you can take them apart and see what size shim you have installed.

After this you can use the graph, at the top you will see what size shims you have installed, then what gap you have measured, from this you can work out on the graph what shim you will need to install to get the correct clearance.

The example on the graph will help

 

Steve

 



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totallyttrs.com

 
TTRfan


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This is the feeler gauge set I use - ideal!  https://estore-sslserver.eu/totallyttrs.com/epages/699105d9-e4cc-4b32-b236-84e72cd67f84.sf/en_GB/?ObjectID=7415088



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JOHNYBOY


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thanks brian i will try can you also answer the other question about shims please i have just cut my seats ground valves in ready for refit i keep looking on ebay for a pilot for my neway seat cutters but cannot find a small one then i can cut motorcycle seats

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mossproof


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As Steve says John, use feeler gauges to measure the valve clearances you have and write them down. Then take the camshafts out and see what shims are fitted, and write them down.
Assuming the clearances are out of tolerance, take your left index finger and put it on the measured clearance value you have (left side of the graph). Now take your right index finger and put it on the shim size that is fitted (the numbers along the top of the graph)
Now slide your left finger horizontally to the right, and your right finger vertically down until they meet. The point at which they meet is the new shim size you should fit to get the correct valve clearance. Repeat for each valve that is out of tolerance. Have fun
Simon.

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JOHNYBOY


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hi steve ive cut the seats so when i build up they will be tight many thanks

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TTRfan


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I had to go down about .20mm when I had valve seats recut and valves reground.



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JOHNYBOY


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many thanks brian i wil lcheck on rebuild at the moment my ttrs running its a spare head to put on when i can be bothered but want to get it shimmed up ready

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JOHNYBOY


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hi folks just worked out how to do the graph wow thats very good i thought it was hard to work out very easy & helpfull many thanks for your help

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JOHNYBOY


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just got head sorted checked clearances all tight so removed camshafts measured shims to size set to reducing them with wet & dry till i got the size i require built back up got them all spot on but what a long time to do it

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Cubber


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It's been said before that patience is a virtue, John. wink

Well done, at least you know it's done and done well.

Martyn



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JOHNYBOY


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yes martin i think mine on my ttr are slightly tight & smokes badly on startup thats why it struggles starting if left for a long time but does not smoke when running so ill try head first but check bore first anyway its not a race bike its a plodder like me

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