Big Bore noise?

I just installed a Kitaco 88cc kit. I set the valve adjustment at .04 mm and it seems pretty noisy. Is this normal or did I do something wrong ? Also, is a 20mm carb the best size for this motor? Thanks for your help.

Dude, I did the same thing and the valves are noisy as hell. I am going to try closer to 0 lash like a SBC hydraulic cam. I ordered the 20 mm carb but I didnt receive it yet, atomrotten said he recommends it.

.06 is a good setting for the .05-.06. Did you guys make sure you didnt over tighten the head nuts? that would squish the gasket and make the piston hit the valves. I would take off the head leave the gasket on and check you clearance. i have heard a few kits where the valve did hit the pistons. You can take your old gasket and seperate it using a layer or 2 to make it clear the valves. Best be safe then sorry.

Later Atom RoTTeN

Thanks Atom! I torqued according to specs but I will check out the clearance.

I removed the head and checked the clearance and everything associated with it,Everything looked ok.I also rechecked the valves while the head was off, I took Atom's advice and took the old gasket and removed 1 layer and put it on top of the new head gasket. Maybe a little less compression, on the other hand i don't need my new xr motor to shatter the piston or bend a valve, I will try it tomorrow.

Whether its on a 50 or whatever when you put in a bigger lift, longer duration cam noise seems to increase and at a rate multiplied by 100. Its to do with the fact that you lift the valve quicker, hold it open longer and then let it slam shut, often with stronger springs. The increased clearence is there to allow for expansion as the motor will generally run hotter and to "soften" the lift and closure. Valve clearence is right. I like a touch more on exhaust but thats personal preference more than anything.

When installing new pistons, cams, heads, barrels, valves always use a bit of modelling clay / putty on the head and valves / piston to check clearences. Assemble the motor but dont fully torque everything, just firmly nip it up, turn the motor over by hand, pull apart, check clay and then properly assemble. Its amazing sometimes with the lack of clearence or just way too much clearence and you can save a lot of head scratching later on.

Hey Woodsrider426 you never told us how it sounds now with the extra head gasket....?

Haven't tried it yet, the bike is in the basement still. We have had real cold weather lately its 14 degrees now and I think that was about the high today. By the weekend I should have it out I think it will be about 30, Wow a whole 30 I am getting sick of this weather real fast. I will let you know.

I've noticed if you don't run HD valve springs with higher lift cams they make a lot of noice and i recommend a takegawa 22mm carb kit.

22 carb is way to big for a 50 head 88cc bore up.18-20 max. Heavy duty valve springs can be used but not nessasry. We run them all day long with the stock valve spings and have no problems and no alot of noice.

Later Atom RoTTeN

i run the 18 and 20 on my ported 50cc bikes and they have really good bottom

Well has anyone of you considered camchain noise? Mine rattles a bit and it is not the valves hitting the piston and seems to be camchain related?? On that note I removed the bolt that holds the tensioner spring and tensioner and the spring seems very weak. I'am thinking of making my own manual tensioner which should not be too hard.

Agree with that but I assumed that you get a new chain when you get the kit. (Not into the XR50/70 stuff :)) The stock cam chain in Honda 4 strokes will stretch pretty quickly, even more when you add a big cam. If it is the "old" chain and I mean even a month or so old get a new heavy duty cam chain. DID do them and should be available pretty easily.

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