Hi all,
I was hoping you can advise me a little more about getting the jetting right. I seem to have 2 speed bands where I get 4 stroking. Around half speed to about 65% max speed and at about 95% top speed to redline. The half speed one you can just slowly Accel through, and even the top end you can sort of wiggle the bike left and right and get a little boost ish every now and again.
I have the zeda80 engine, and it currently has only a 36tooth sprocket added - I have a proper mz65 in the post, but it's not arrived yet.
I bought a bunch of dellorto 1486 jets for the carb,
I started with 62-66 (they were quite pricey and I didn't want to fork out a large sum for the 60-80 set on eBay cos the shipping was crazy).
The 66 seemed the best but it got very, very, hot and I only rode it round the block twice.
Its always ran hot, the original user manual says you should be able to touch the head but you can't touch mine for more than half a second, even after driving it to work-about 7 miles and back each day.
With the 66 jet The water drips dropping from the frame were vapourising on the exhaust, 67-69.
I tried the 69 today and it seemed to sort out the 4 stroke zone at about half speed. But still got it towards redline. I only went aroud the block twice. It seemed a bit sluggish at the very low speeds, but an overall improvement from the stock by jet (which I took from the stock nt carb, cos that was better than the stock hp carbs ( - but it doesn't have a number onit).
I am worried about the heat. I don't want it to get too hot and destroy itself.
My questions are: do I keep going smaller until the 4strokig completely goes away throughout the speed range?
Is it meant to run at a much higher temperature to the standard HT carb jet?
Are there any trade offs from changing the jet? Like you'll loose some power low or top end depending if you are running a larger or smaller carb jet?
What are the symptoms for a much too small jet?
I was hoping you can advise me a little more about getting the jetting right. I seem to have 2 speed bands where I get 4 stroking. Around half speed to about 65% max speed and at about 95% top speed to redline. The half speed one you can just slowly Accel through, and even the top end you can sort of wiggle the bike left and right and get a little boost ish every now and again.
I have the zeda80 engine, and it currently has only a 36tooth sprocket added - I have a proper mz65 in the post, but it's not arrived yet.
I bought a bunch of dellorto 1486 jets for the carb,
I started with 62-66 (they were quite pricey and I didn't want to fork out a large sum for the 60-80 set on eBay cos the shipping was crazy).
The 66 seemed the best but it got very, very, hot and I only rode it round the block twice.
Its always ran hot, the original user manual says you should be able to touch the head but you can't touch mine for more than half a second, even after driving it to work-about 7 miles and back each day.
With the 66 jet The water drips dropping from the frame were vapourising on the exhaust, 67-69.
I tried the 69 today and it seemed to sort out the 4 stroke zone at about half speed. But still got it towards redline. I only went aroud the block twice. It seemed a bit sluggish at the very low speeds, but an overall improvement from the stock by jet (which I took from the stock nt carb, cos that was better than the stock hp carbs ( - but it doesn't have a number onit).
I am worried about the heat. I don't want it to get too hot and destroy itself.
My questions are: do I keep going smaller until the 4strokig completely goes away throughout the speed range?
Is it meant to run at a much higher temperature to the standard HT carb jet?
Are there any trade offs from changing the jet? Like you'll loose some power low or top end depending if you are running a larger or smaller carb jet?
What are the symptoms for a much too small jet?