Frustrated and looking for help.

[fabiodriven]

SO, I decided to fatten up my jetting a bit for the winter about two weeks ago. I have had a problem with a "Death rev" and an erratic idle since. Here is the story-

About two months ago I finished a top end overhaul on this trike (85 Tecate). I installed an NOS KX250 cylinder and a brand new Wiseco KX250 piston. The trike ran fine after that, but on the first trip out she was a bit lean, mostly in the mid range. After that ride I removed my 270 main jet and installed a 290. I moved the clip down one notch from the middle (to pull the needle up one notch) to account for the mid range lean condition. I also installed a brand new Johnny Swinehart intake boot which appears to be fine. After the re-jet I got a slight death rev and an erratic idle. It sounds like a lean condition, obviously. Today I put the circlip back where it was on the needle and I still have the same problem. When I am finished writing this I am going to take the carb and intake boot right out and inspect everything. Compression is fine and the crank bearings and seals were done about 5 years ago. I am hoping to find something obvious when I rip into it, but if there are any ideas floating around in your squashes, I'm game to listen. I'm pretty frustrated here. Icefest is right around the corner.

Thank you guys.

[zzmegad]

i know this is the obvious answer but check if your pilot jet is clogged, or maybe go up on that. When I got my triz the guy had too small of a pilot in there and it was doing that death rev you descibe. When I put the correct pilot in there, thing idled down and purred soon as i pulled in the clutch

[fabiodriven]

That's not a bad idea and I do need to change it anyways, but I don't understand why it didn't do that with the 270 main in there.

[Dirtcrasher]

When you pulled the carb off, you took it off the boot or rotated it, any chance of an air leak?? Squirt some stuff around there??

[fabiodriven]

Stupid question- Does the arrow on the reed cage face up or down? I'm guessing up, but I don't think it should matter all that much.

[200XMichigan]

I feel like I am pointing out the obvious but did you use a new reed cage gasket? Check the reed cage block for warpage?

[fabiodriven]

The old reed cage gasket was fine, but I am now replacing it anyways. I have a gasket here so why the hell not?

I did find a potential issue in the carburetor. There is a little plastic donut looking thingy that looks like it used to be around the main jet. It's just floating around in there and I can't see any way it would be attached to anything in the carb. I'm gonna leave that out and see what happens. Anybody know what that thing is?

[puggerton03]

it slides over the main jet. kind of clips into place. Im not positive but i think the reed cage can only go in one way. the intake boot wouldnt line up with the carb if it was in wrong. if the plastic thing was in there loose it might have been able to prevent your float from working properly.

[fabiodriven]

Thanks Pugger. I can see where it's supposed to go now. It will not clip though. It must be worn out.

[200XMichigan]

They loose their squish over time. I put a new one on my YT175 and it helped a ton. It visually looked fine. It wasn't doing a death rev but its idle was extremely erratic.

Is it like a white plastic donut, kind of like a cup with a hole in the center? It should go right around the main jet, under the needle seat. But it could be brittle and old, if it came off it must be defective since the only way to take it off or put it on is to remove the main jet. It should face downward, like an upside-down bowl. I'm sure the floats didn't like it bumping into them.

[dcreel]

The arrow on the reedcage should face down.

http://i176.photobucket.com/albums/w182/dcreel/001-32.jpg

[fabiodriven]

Well it's back together now and running quite well. It appears as though the problem was that little donut that had come loose. I am currently running it without the donut and it seems fine. I will also add that I put the reed cage in upside down (Thanks for the picture Doug).

With the bigger jet in there I have discovered the power that I thought I was losing after going from the Tecate jug to the KX jug. I may even fatten it up some more and see what happens.

Thank you all for your help.

[hang&rattle]

Hey fabiodriven? What's your elevation and round-about temperature? And what's the size of your carb? Thanks, all this stuff is really helpful. I just spent around 4 hours swapping, cleaning, and messing with carbs for my daughter's auto-x to get the right set up, you just helped pave the way for my Tecate so I won't have to come down to all that when needs be.

[200XMichigan]

Here's a link for free factory Tecate manuals.

http://tecateprojects.com/manuals.htm

[fabiodriven]

The temperature has been varying a lot lately Hang. Today it feels like almost 40, but two days ago it was 0. I am trying to figure out my cold weather jetting at the moment. I am running the stock round slide Mikuni at 34mm.

[hang&rattle]

O.k., then you're my new best friend, lol. I've been having trouble with below 0 then 45 degrees 2 days later too. I'm not pulling my carb and changing jets every 2-3 days as the weather dictates, I'm an idiot, but not stupid, lol. But I'm having trouble on both fronts, changes in elevation and temperature. One more question, where's the best place where you get your jets? They are ridiculous here and I can buy a whole new carb for the price of the darn jet kit.

[Backfire]

could be your needle, mine's worn out and my idle is all over the place

[Cave Rider]

The plastic "donut" was designed to prevent fuel atomization when going over bumpy terrain. Your tecate will run fine w/out it. However when summer rolls around and your off of the smooth ice,you may want to replace it. That way you wont get a bogg over the jutters...braaappp !!!! (nice toys by the way)

[fabiodriven]

O.k., then you're my new best friend, lol. I've been having trouble with below 0 then 45 degrees 2 days later too. I'm not pulling my carb and changing jets every 2-3 days as the weather dictates, I'm an idiot, but not stupid, lol. But I'm having trouble on both fronts, changes in elevation and temperature. One more question, where's the best place where you get your jets? They are ridiculous here and I can buy a whole new carb for the price of the darn jet kit.

You do know you don't have to remove the whole carb to change the main jet right? All you have to do is loosen the clamps, tilt the top of the carb towards the kicker, and remove the plug at the bottom of the carb with a 17mm. Then you just need a 6mm socket to change the jet.

I bought jets a couple of weeks ago at the Polaris/Acrtic Shat/Triumph/KTM/Husquervarna dealer up the road. I think they were 2.60 each? I brought one with me and I just compared it to what they had in stock, which was quite a bit. They had a whole big bin. They're only like 3 miles up the road if you're having trouble finding some. I can ship them to you.

(I gotta double check that price)

[hang&rattle]

I told ya I was an Idiot...., I've been removing the carb. Didn't think I could get to it otherwise. I'll hit you up on your help offer when you kinda get dialed in. I'll probably be some what close to your jetting, at least it's a starting point as I've been hit and miss (mostly because the cold then warm temps.). Thank you fabiodriven, thank you-

[dcreel]

John, if you want to see a huge increase get a 38mm or larger carb.

[puggerton03]

Crap, now this thread has me thinking about whether or not my reed cage is in correctly. I think I put it in with the arrow up not down. Wonder if it matters?

[fabiodriven]

I'm fairly certain it doesn't matter which way you put it in Pugger. I looked at that thing for a long time and it appears to be perfectly symmetrical to me. Mine is in the wrong way right now and the trike is running fine.

[200XMichigan]

I told ya I was an Idiot...., I've been removing the carb. Didn't think I could get to it otherwise. I'll hit you up on your help offer when you kinda get dialed in. I'll probably be some what close to your jetting, at least it's a starting point as I've been hit and miss (mostly because the cold then warm temps.). Thank you fabiodriven, thank you-

You gotta remember you and fabiodriven are at totally different elevations when jetting (I am just guessing by your pic of the mountains) but elevation has a lot to do with jetting. Higher up has less oxygen, but colder air has more oxygen. So you would probably want to run a little leaner than he would be at the same temp.

Also you should check a sled shop, they usually sell individual jets for cheap. Just bring in your old ones and match up the style of jet.

[fabiodriven]

You gotta remember you and fabiodriven are at totally different elevations when jetting (I am just guessing by your pic of the mountains) but elevation has a lot to do with jetting. Higher up has less oxygen, but colder air has more oxygen. So you would probably want to run a little leaner than he would be at the same temp.

Also you should check a sled shop, they usually sell individual jets for cheap. Just bring in your old ones and match up the style of jet.

Good advice, except he is going to want to run richer than me I believe, no?

Also good advice about the sled shop for jets. That's where I get mine.

[200XMichigan]

Because there is more oxygen in cold air, in winter we make it richer. So if there is less oxygen in higher elevation you would make it leaner. Someone that lives in the upper elevations could chime in on this but I am pretty sure this is correct. I found this out the hard way, bought a bike in Sante Fe, lived in Albuquerque. Went to drive home to Michigan and it over heated in Kansas because it was running too lean for the elevation in Kansas and it was jetted for 6000 ft.

Do you just re-jet the main and needle position for temp? Or just the main? I was under the impression you had to change the pilot jet too. Would be a lot easier to just change the main.

[WIkid500]

You guy's are right, Higher elevation means less jet (leaner) because the air is less dense then at sea level or lower elevations. Colder weather the air becomes more dense (more Oxygen) this means you want more fuel to keep the mixture correct.

This is a good post, lots of good info going on here.

[fabiodriven]

OK, so it's leaner in higher elevations. Got it.

I replace the main jet with a bigger one to go richer (obviously) and I believe you adjust the main needle up to fatten up the mid range. It is a good idea to do the pilot as well, but you can get away without doing it. I will do my pilot soon.

[hang&rattle]

Yup, I mentioned (elevation) the post in 14 and 16. I'm kinda dealing with both issues, and every bike is different. But we both run similar carbs and pipes, and fabiodriven will get it closer than I have for the changes in temperature. And ya, I moved the clip up one notch, but the weather went warmer, so I moved it back down (now it's cold again, lol). I'll be able to run alost exactly what faviodriven is except move my clip. Tried to simulate a 250R close to my conditions, but man, way different 2-stroke there. Tired of the hit and miss, glad fabiodriven is on it.

[WIkid500]

Yup, I mentioned (elevation) the post in 14 and 16. I'm kinda dealing with both issues, and every bike is different. But we both run similar carbs and pipes, and fabiodriven will get it closer than I have for the changes in temperature. And ya, I moved the clip up one notch, but the weather went warmer, so I moved it back down (now it's cold again, lol). I'll be able to run alost exactly what faviodriven is except move my clip. Tried to simulate a 250R close to my conditions, but man, way different 2-stroke there. Tired of the hit and miss, glad fabiodriven is on it.


FYI you want to move the clip down for colder weather. Moving the clip down raises the needle in the main jet which adds more fuel in the mid range. Maybe this is what's giving you some troubles jetting?

[hang&rattle]

O.k., I see guys, thanks. I was told to move the clip up one notch for my elevation at 4,000 feet. But when it got cold it 'bogged'. My plug turned tan, so I moved it down to center. It runs excellent in the low teens to single digits. Above that (warmer) it bogs in 5th WOT, even fowled the plug once. So now I know to move the clip one notch down from center and both may need to be bigger. Thanks, it's kinda making sense. This drastic weather (and everyones got it) and when we ride we can go from this valley floor (4.600ft) to over 8,000ft in an hour's time. Poor trikes, but so fun though, from the lake to the Rocky Mountains.

[Meat-BoX]

Just contacted Rich at Bristol Racing here in C.N.Y. for the Jets I may need. He was very knowledgeable and from what I heard from people around here they were the original speed shop here in Central N.Y. tHEY HAVE A RICH HISTORY WITH RACING 3 WHEELERS AND i TALKED TO HIM ABOUT THAT ALSO. hE IS GONNA HELP ME OUT sATURDAY WITH THE JETTING AND WERE GONNA TALK ABOUT SOME PORTING AND OTHER STUFF. He was supprised to hear about three wheelers coming back and told me about his Tecates he used to race. So I hope to see if he has a secret stash of parts or knows someone who might have some stuff. But best of all hes gonna help me get dialed in and hopefully running right. I may make Ice Fest 2011 after all.