Tecnigas Trek for People 2T

[chaz35]

That's cool, yes these are amazing little engines.  Cheers

[mclark999]

So I'm a little frustrated trying to tune this. I had installed larger main and idle jets and opened up air box by drilling a bunch of holes in it. Ran good at all throttle settings but was hard to start when it was warm. Then I opened up the snorkel and plugged up the drilled holes. I measured and calculated air openings, but now it won't start.

I tried the original idle jet and if I heavily choke it by covering the snorkel, it will start but I can't tune it to idle right or respond right as I open the throttle. It's a 35 jet and seems lean.

With the 40 jet in it, I can't get it to start unless I take the air box off and it will barely start even then, so too rich.

With 38 jet, I can't get it to start at all. Urg!

Will keep trying.





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[chaz35]

have you adjusted the idle mixture screw?, what's it set at?, maybe carb needs good cleaning?

[mclark999]

have you adjusted the idle mixture screw?, what's it set at?, maybe carb needs good cleaning?

Yes to adjusting idle mixture screw (when I can actually get it started). That's partly how I can tell lean vs rich.  With the 35 slow jet it idles best, but not good with it screwed out so far that it's almost falling out. With the 40 jet, I have to have it almost all the way in (1/4 turn out) to get it to run. So I need something in between and as you'll see below, the replacement jets I have aren't exactly the same so I'll have to try various sizes.

When I first went to rejet, I cleaned the entire carb very well and it was running well after my first round of jetting and opening up the airbox so I think I have it clean enough.

I put the new idle jets under a 4x magnifying glass and discovered they are slightly different than the OEM jets. They have 3 atomizing holes instead of 4 and the atomizing holes are slightly smaller.  Maybe they are slow jets for a 4 stroke.  I have them in every size, so I'm going to try a few different sizes and see if one of them will work.

[chaz35]

Where did you get idle jets?  I got mine from jetsrus and if I remember correctly, the cheap generic idle jets didn't work for me either.

I ordered one and had trouble with it.  So, after that I ordered OEM Keihin idle jets from jetsrus, and they worked well.  Didn't have any trouble with the generic main jets from jetsrus.

[paceneedsstides]

I can't help on this as when I put on exhaust she ran fine with same jets in and two weeks later I installed the Dellorto I did absolutely zero tuning on the stock carb

[mclark999]

Went one size richer on the idle jet and it will start with hand over snorkel and almost idle without. Still too lean.

Will go up two sizes and try again.

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[mclark999]

Took it out for a ride. Impressed with how much power and speed a fifty cc motor can make. Still need to upjet idle, but probably just one size, not two.

Started right up from cold start.

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[paceneedsstides]

sounds like you almost got her beat into shape

[mclark999]

Went up one jet size on idle. Starts okay hot. Need to try cold start in the morning.

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[mclark999]

Started at first turn of key this morning and then died. Had to hand choke by covering the snorkel to get it going.  I may quit fiddling with it now as its easy to hand choke when it's cold and it starts right up hot, even if its sat long enough for the auto enricher to kick in.

Think I'll now go one size richer on the main and see how it runs. Want it to be a little rich, not a little lean.

And still hitting 50 on the speedo on the flats. That's probably about 45 actual. There is no flat road with 45+ speed limit near my house where I can do a gps run. Now that I can get it started anywhere, I'll take it further away and see what gps speed I'm getting.

[mclark999]

Been fighting a weird issue where it didn't want to idle when it was hot. Think I got it fixed with new spark plug

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[mclark999]

It hasn't been idling good so I tuned it up today. Took it out on the freeway just now to see how fast it will go with the Trek pipe I put on it. Speedo said 60ish. Probably only 53 or 54 actual. I'll gps it next time.


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[mclark999]

Final jetting is 92 main and 38 slow/idle. That's at 5300 feet elevation and with the stock air box with the snorkel removed and the opening cut out to the edges.

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[mach65]

i want more speed and want to buy an after market exhaust but after reading this thread and hearing about the idle and starting problems, maybe i am better off just leaving it alone, i'm doing anywhere from 35 - 41 on the speedo as it sits stock with a smooth boss installed.  most of the time 35 - 40 is just fine but rode it 45 miles up to south beach yesterday and wished I had more speed.  plus when i got there, there are a lot of hopped up scooters running around south beach, made me want more speed....... what to do???  suggestions anyone?