Trials Australia Forums

Going by what info I can find online and the frame number, I have a 1976 TL125S. I'm chasing a new set of inlet/exhaust valves and finding some differing size between 2 different heads I have and what I can find listed as part numbers and ebay listings.

Using the cmsnl site i come up with part numbers
inlet 14721-324-010
exhaust 14711107020
all the descriptions say these valves suit CT100, CT125s and a few others. Problem is the other head I have is supposed to be off a CT125 and it has smaller valves? It looks like a carbon copy except for that. Both heads have a different number code in the casting on the bottom fin.

the big valves measure Approx mm
inlet 29 diameter - 93 long
exhaust 24 diameter - 93 long

So can someone tell me whether I have a rather rare head or are all the real TL 125 heads made with big valves? And some part numbers would be swell.

I have been doing some research and it I'm now thinking the small valve head is the original and the big valve head is the CB/SL/XL or something.

Most people say that the big valve head robs low down torque. Pity cause the original head has the camshaft area worn out. And while my Dad can machine it all up and install bearings in it, bit too much work for the moment.

Any idea where I may get an actual measurement of XL125 Valves?

http://www.bkperformance.com.au/index.php
http://vincentcrabtree.web.officelive.com/XR200.aspx

These websites were helpfull...just bought a inlet valve for my TLR 200 through Bert @ B.K.'s 27mm x 92.5mm Long. Was a CB100 inlet valve.

Give him the part numbers and exact measurements and he should be able to help.

Cheers

Bigger valves will tend to increase power/torque, as long as the size of the ports is not overly large. A nice way to reclaim damaged Honda heads is to bore the worn out cam bearing area to remove the wear, metal spray cam and machine that to fit the oversize cam bearing. This is a better option than fitting bearings, which tends to weaken the heads to some extent, as much more material must be removed to fit the bearings.

While we have topic on Tl125 - I thought I would alert you an opportunity to acquire two tools that may come in useful - have had them since '76 - the OHC valve compression tool and by memory the four pronged tool to remove the oil pump. Usual story - only ever used a couple of times, only ever on weekends or late evenings and saved hassles of trying to find an equivalent in the back shed. Let me know if you are interested and we can sort something out. Pick up in WA or cost of postage over east/overseas. These are genuine classic - worthy of restoration to prestine condition.

Thanks for all the replies. Bert from BK performance is highly recommended! He knew straight away that the head was a CB125J/N and had the valves in stock. Not to mention quite a few other bits n pieces for my TL.

I'll pass on the tools for now, thanks anyway. Don't wanna take on too many restoration projects at once