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How to check valve clearance
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i really dont want to give up on this bike .....but my funds are running low.....when i bought it the guy said it had a fresh top end rebuild from a shop .....he just couldnt get it wired back up when he tried to install the motor back on the bike .....I ordered a new harness and figured out the main had gone out.....I can get the bike to crank but not turn over....I've tried starter fluid and gas directly in the spark plug hole ......the spark plug hole has been re tapped .....it now fits dr8ea or dr9ea.....I was thinking maybe the valve needed adjust so i took the top end apart .....it looks like he was telling the truth ....piston and cylinder look flawless .......I'm not sure how to check the valves though .....I've only dealt with 2 strokes .......I've check internet videos and youtube videos but they all seem different than my Ttr.....any suggestions or can anyone give me a starting point on things to check while the heads off?



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The engine parts look great - should be a nice runner when you got it fixed.

Valve clearance adjustment covered here 

Lots of other "show and tell" guidance here 

Hope it all goes well and you get the TTR running.

Brian



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In the process of inspecting everything I found this......how can i get it scrwed back in level ? It's stuck ....the one for the rear seems fine it's just the one in the front that's come out while trying to get the nut out 



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Can you borrow a stud install tool like this one?

Otherwise Vice grips on the collar might do it. But they will leave some biggish bite marks!



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pug


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tip 3
Try locking two nut's one against each other on the thread then wind down the top nut should turn it back in it always works for me

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Thanks guys ....the 2 nut method work after letting it sit in penetrating oil for a while .....backed it all the way out cleaned the inside of the threads up w q tips and used the same 2 nut method to turn it back in....you guys are awesome !

 



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Don't think anyone can beat a Bri/ Martyn techno combobiggrinbiggrinbiggrin



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TTRfan wrote:

The engine parts look great - should be a nice runner when you got it fixed.

Valve clearance adjustment covered here 

Lots of other "show and tell" guidance here 

Hope it all goes well and you get the TTR running.

Brian


 Hello all,

 

I've been away from the forum for a while, as my partner Anna's TTR has been running like a dream all the way through our trip through Russia to Mongolia and the occasion green lane in the UK since.

 

But now I am need of advice as it came to the time where some major maintenance was necessary.

 

At the same time we decided to fit the 325 kit from thumper racing and during the rebuild, after having the engine, barrel and head modified by a machine shop, I noticed my camshaft clearances are very low , without shims installed.

 

I'm getting 0.017 and 0.015 thou on the inlets and 0.007 on both exhausts, again, with no shims fitted.

 

I found this after fitting the shims I took out pre machining, and when I tightened the camshaft caps down, the camshafts would not turn, and had no measurable clearance.

 

So ive taken the shims out and I'm measuring the clearances above.

 

I had the valve guides replaced for new, and the valve seats re-cut. But by my math, the engineers have removed upto 1.35mm of material from the valve seats/valve faces, meaning the top of the valve stems sit 1.35mm closer to the cam shaft lobes.

 

There is no shim that I can buy that will take the inlet clearances into spec as they are all too but, starting at 1.20mm.

 

Question is, can I run without shims fitted, or am I looking at new valve seats to sort this problem?

 

I don't want to continue with the rebuild of the head until this problem is sorted as it could prove to be even more costly, especially if the current cable seats are too thing to dissipate heat effectively now I've the big bore kit fitted.

 

Many thanks for any advice you can all give, we were so looking forward to getting the engine back and rebuilding it, but now we have this disappointing problem to deal with.  :'-(

 

 



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Will see what others have to say but no shims should be OK as long as there's sufficient gap (haven't come across it though)  in the cases when seats and valves are machined  in other engines I've also taken a bit off the top of the valve stem to allow for the machining keeping the need for shims 



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pug


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Stick with shims in take the extra off the Valve head to bring it within adjustment of the shims if you don't have the tools to do it take it to a engineers shop its best dun with a Lathe and tool post grinder. But can be dun post apocalyptic Mad Max hard times with a bench grinder a good eye and a calliper gauge

Pug

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Hi Howard and good to hear that Anna's TTR ran well through Russia and Mongolia - probably all to do with your excellent preparation smile

Your measurements of the existing clearances are in thou and Google reckons 0.017" is 0.4318mm, 0.015" in is 0.381mm and 0.007" is 0.1778mm 

I would be wary of letting the cam caps run directly on the valve spring retainer or valve stem so one solution would be to thin out a 1.20 shim to what you need. Some motorcycle engineers do this as a matter of course to get the exact clearance they want.

You say that the machine shop re-cut the valves. Depending on how much they removed, new valves might restore some clearance although an expensive chance to take unless you can compare your valves with new.

Les's and Pug's suggestion of machining some material off the top of the existing valve stems sounds a good solution and give you the possibility of adjusting clearances in the future if required.

I think you may need to account for valve clearances reducing with wear as valve heads bed into their seats - is that right Les/Pug?

I prefer the thinning out of shims solution wink

Brian

 

 



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Agree thinning the shim is a good option 

Taking a bit off the valve stem is usually done in a machine shop so the end is square and contacts the shim properly 

Agree clearences tend to close up as valves settle in and the seats wear 



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Hi all, thanks for the quick replies.

I am going to go over everything again tonight as after phoning the engineer who carried out the work, he assured me that he only took off a max of 20 thou in refacing the seats and valves.

With that in mind, as I was running approx 1.80 mm shims beforehand, so now he's removed a max of .508mm (20thou), it stands to reason I should require about 1.30 mm shims.

He suggest that the shims weren't sitting on the valve stem heads correctly, but instead, sitting on the valve spring caps somehow, in turn raising the cam followers. Not sure how that's possible but I will get a fresh set of eyes on it tonight and report back tomorrow for anyone that's interested.

I could grind down shims, but currently, the biggest shim I would need is one that's only 0.18mm thick. Not sure that would stand up to the load very well?

Brian, were you still after the new dimensions for the 325 sleeves supplied by thumper racing?

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heffh084 wrote:

Brian, were you still after the new dimensions for the 325 sleeves supplied by thumper racing?


Yes please!



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Hi Brian,

 

Here are the dimensions of the 325 sleeve I was sent, at least according to my £20 digital caliper



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So I was just about to assemble the head for the last time post valve clearances and when I turned my head upside down, one of my spring seat fell out.

 

Odd I though as usually there is enough oil to keep them sticking to the head.

 

On popping it back in, I've noticed the seat rocks on something. A bit of grit I thought.

 

Nope, looks like the engineers who rebuilt my head have not fitted the valve guide retaining clip in fully, so the spring seat can't sit flush on the bottom.

 

Is there any chance I can reseat the  valve guide at home? How much heat do I need to apply to allow the guide to press out?  Can it be done with a heat gun? Or if I put the head in the oven for a short while at 100°, will that allow me to press the seat out, reseat the spring clip and press the guide back in?

 

Or am I best taking it to another machine shop and spending yet more money?

 

Many thanks for you help again!



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personally i would take the head back and get them to sort it but can understand after your problems that you may not want to take it to the same place
maybe get another place to have a look maybe report on the previous work.. im not sure what you have paid for exactly but if i was re-conning a head or even cutting seats i would also be shimming the valves/ to set clearance at the same time it shouldnt be your problem of making custom shims if they have cut the seats too deep.. it would also have an effect of having less spring seat pressure too unless they have made more spring seat shims to compensate..
im asuming all this of course as i cant be certain hwat you have asked for or been charged for but it all sounds a little dodgy..
si

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I asked them to replace the valve guides, and recut the valves and valve seats. I didn't supply the camshafts but now I realise I should have, but they didn't ask for them either.

Still, I've got the valve clearances set now, but it's just this valve guide clip that's not right now.

Sadly the machine shop isn't local, so I'm reluctant to pay for shipping both ways. I think I'll take the head to a local guy some stock car guys have recommended. Hopefully he can reseat the valve guide with the clip in the right place!



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