Upgrading stock 26cc topend

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
Ok thanks, looker do you think there would be much difference between the two engines that I was talking about? I'm gonna go for the Chung yang because of the price....
 
One more question do I need to break in the engine when I install the top end. If so how long and in what way?
Cheers
 
Being as you are learning, I would suggest this stock 36mm kit.
http://www.davesmotors.com/chung-ya...bore-up-kit-38mm-skirt-2-bolt-236214036-.html

The only break in I do to my engines, is I run at leat 3 heat cycles through them before running them like normal ( Hard ).

1st I allow the engine to run at idle for 15 minutes.

shut off and let completely cool.

2nd I allow the engine to run just higher than idle for 15 minutes.

shut off and let completely cool.

3rd I allow the idle, with occasional full throttle blips to help clear any build up of oil out, and I do this for the last 15 minutes.

Let cool & recheck exhaust bolts - Then Run it like normal ( usually quite hard ) LOL ;)
 
Hey I have one more question would it be a good idea to change the needle settings back to stock for the break in?
Cheers help much appreciated:D
 
Ideally what you want is 'a little rich of ideal', to permit cooler running and better lubrication.
Tolerances are generally very good but none are identical, so the 1 1/4 / 1 1/2 L / H setting is an approximate figure.
Don't choke / flood the motor, but as indicated above its better a bit rich than a bit lean - at least to start with.
Al.
 
Ok cool I might put the high speed even like 1/8 th of a turn richer then the stock...
 
Don't hurt to run it a bit richer for the first tank or so.
1/8th turn is quite a bit, but worth a try.
Worst that could happen is fouling a plug really.
 
Hey guys just thought that I'd update this thread I broke the engine in and then I started tuning it and when I tuned the low end the idle was high and then I noticed that I had blown the cylinder gasket but defently noticed an increase in power but still has more power to show I think because I havnt fully tuned it properly...

Peace out
 
Happened upon the thread while figuring out what engine to build for my wintertime Losi project and it seems you've gotten a lot of good info! I did read something that brought to mind something else to check once you have the new head installed. Looker2756 mentioned not letting the gasket material "squish" out, so the credit really goes to looker.
Using a kit you should be fine (they should match you up with the right head gasket), but anytime I make changes like that I always check the squish of the motor as well. Takes a minute and gives you some piece of mind. Everyone here knows how much money we dump into these beasts and taking a minute to make sure your engine is going to perform might also save you a headache. Wish you luck on it, and let me know if you need some info on checking the squish, or if you decide you want to get adventurous and do some bottom end work as well.
 
How do ya check the squish I did hear about it but people said you have to by special tools for it so I didn't worry bout it... By the way I bout a 0.12 copper head gasket and the engine runs even better.
 
Put some clay or play dough on the top of the piston and torque the head and gasket down and turn the engine over. Now take the head off and measure the depth of the clay or dough that will give you the clearance.
 
I use thicker solder or if you're a fisherman like me I will sometimes use the lead wire I use for fishing lures. Bend a 90 in it and stick it in through your spark plug hole...pull up on it until it makes contact with the top of the head...turn your engine over...pull out the solder or lead...then measure where it has "squished" the wire/solder down with calipers. Hope this helps.
 
Back
Top