Mrploppy Posted June 14, 2021 Report Share Posted June 14, 2021 Hello everyone, looking for help with my 150cc upgrade kit. its all assembled with the new piston and barrel but the original cam chain is now too short. I measured the height of the new barrel and it’s slightly taller than the original 125 one hence the old cam chain just fits but is way too tight even in its most loose setting on the tensioner. The kit is Berlit. so I guess I need an extra link or two longer can chain? where to find one? has anyone else experienced this problem? any help or advice gratefully received, kind regards, Andy Quote Link to comment Share on other sites More sharing options...
gbmoto Posted June 15, 2021 Report Share Posted June 15, 2021 Hi Andy You probably need a half link. If you purchased it from Leezy they should supply one. I have one of their roller bearing heads and that needed a half link that they supplied. Quote Link to comment Share on other sites More sharing options...
carl ekblom Posted June 15, 2021 Report Share Posted June 15, 2021 I have no knowledge about TL125. OHC I think, but I have seen this type of problem several times If you alter the length of the cam chain you may also alter the camshaft timing. You must carefully do all calculations first and always check the timing marks but a degree wheel is better. Also check the cam tensioners. Specially the guide (at the front, engine rotation anti clockwise) It has an impact of the timing and tightness of cam chain. Geting a factory manual and see what they say is always good (or essential). Perhaps you can find the correct dimensions. I would skim the barrel to correct heigth and perhaps also have to adjust the compression ratio. I would also check the thickness of the head gasket. A thicker headgasket would alter the cam timing and can make the cam chain tighter If your cam chain have a split link there are pliers that can be used to ease the reassebly. I think it is a matter of getting things as the designers wanted it to be from the beginning, but with some extra cc Quote Link to comment Share on other sites More sharing options...
stpauls Posted June 15, 2021 Report Share Posted June 15, 2021 17 hours ago, Mrploppy said: Hello everyone, looking for help with my 150cc upgrade kit. its all assembled with the new piston and barrel but the original cam chain is now too short. I measured the height of the new barrel and it’s slightly taller than the original 125 one hence the old cam chain just fits but is way too tight even in its most loose setting on the tensioner. The kit is Berlit. so I guess I need an extra link or two longer can chain? where to find one? has anyone else experienced this problem? any help or advice gratefully received, kind regards, Andy If you search the web, or e.bay, someone sells 100 link cam chains. The one I bought was branded "Tour Max". However, I cannot remember where mine came from. Here's one here. 25H 100 Link Cam Chain For Honda XR200R XR200 XR185 XL200R XL125 XL100 TL125 | eBay Quote Link to comment Share on other sites More sharing options...
trialman Posted June 15, 2021 Report Share Posted June 15, 2021 worked at a honda dealers for many years. the tl125 was originaly fitted with a cb750 piston to get it up to 150cc[note,to bore out the barrel has to be a 124cc not the 122cc K1] ,and you used xl185 gaskets.Altering the cam chain length DOES NOT alter the timing!! its the sprocket size that sets the timing. its odd that you say the barrel is taller, the xl185 is about 5mm taller and uses longer chain so you might have to try one of those.it sounds like a codged supplier if the barrel is taller?? I used to run a mega tuned road version with big valve head and 185 barrel shortened to suit the 125 crank [shorter stroke gives more revs] used to rev to 13,500rpm. good way to go big is to drop on a xl185 engine and put your trials gearbox in it?? I run one with a 6speed box for trials and its pretty handy in the vmcc trials. also the vmcc are great trials if you want a fun day out and the lads are very experienced and helpful..All the best, have fun..TRIALMAN 1 Quote Link to comment Share on other sites More sharing options...
Mrploppy Posted June 23, 2021 Author Report Share Posted June 23, 2021 Thanks everyone for all your help. ive purchased a split link and a half link but haven’t had time to fit it yet. the split pin is very fine and gives me the heebygeebies! If it failed my top end would be toast. Has anyone put a very small tack of weld on a cam chain? any thoughts on this? Or should I man up and stop worrying about it 🤪 again, really grateful for all your opinions and advice as I consider myself a bit of a bush mechanic but not an engineer or engine builder. kind regards Andy Quote Link to comment Share on other sites More sharing options...
Antonio Posted July 8, 2021 Report Share Posted July 8, 2021 I would not manipulate the cam chain in any way, this chain goes at very high speed, a closed by the manufacturer unit is best. The price of cam chains is low, try with an xl185 chain, I have an unintalled one for my RS200 T if you need to know anything. Regards 1 Quote Link to comment Share on other sites More sharing options...
hondaphil Posted August 6, 2021 Report Share Posted August 6, 2021 You will find the cylinder is 1mm taller, I found this with the kit from him. You need to machine 1mm from the bottom of the cylinder for this item to work correctly. Do not use a connecting link or change the length of the chain. I can not believe Leezy is still supplying these when he knows they are not correct. 1 Quote Link to comment Share on other sites More sharing options...
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