Tecate won't idle

[6spdls1z28]

Stock carb on my 86 only idles when cold with the choke. Has new intake boot, been cleaned. Runs good otherwise. Also sprayed the outside to see if it would die from an air leak nothing happens.

[fieldy]

So does it die or rev when it won't idle? It dies instead of idling I presume.

[6spdls1z28]

It doesn't die instantly with the choke off tries to idle but really low then dies. I turn the idle up it still does it but takes forever to idle down. And when I spray outside I hold the gas at a steady low idle and it doesn't change.

[fieldy]

I will quickly say that maybe you got dirt in the carburetor. A pilot jet is the idle circuit. You know this... Clean air and fuel supply. I have an rm that is acting that way and I kicked it and sucked a mouse nest in. I know I have to clean the carb, even the tiny holes you can hardly see looking in the venturi.
You have anymore details on the top end of the machine? Guys here are gonna wanna know.

[6spdls1z28]

All stock uni filter and dg pipe. Guess I can take it apart again. I do need to jet it . Bogs slightly on top end probably from the pipe.

[barnett468]

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try spraying flammable brake cleaner gently around with the long nozzle that comes with it.

try adjusting the fuel mix screw 1/3rd at a time.

take a compression test.

your elevation is pretty high so this could be contributing to the problem . . you loose around 4.5 to 5 lbs of compression for every 1000 foot increase in compression so if the stock compression on the tecate was 170 at sea level, you would have around 130 to 135 at 5000 feet which is around a 20% decrease which is huge . . if you have compression loss from worn rings, it will only add to the problem.

if you never ride it much below 5000 feet, i would consider having the cylinder head machined to try and increase the compression.

unike the honda atc250r, the tecates were designed as a high performance bike, and in general, high performance vehicles just don't like to idle . :lol:

[barnett468]

All stock uni filter and dg pipe. Guess I can take it apart again. I do need to jet it . Bogs slightly on top end probably from the pipe.

ok, the plot thickens.

take a photo of the spark plug and post it here.

try a 1 size smaller pilot jet.

you will likely need to change the main jet also.

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[fieldy]

Really direct compressed air and maybe carefully run wire tool through all passages in the carburetor. Any history of when this began and the performance notes (like you posted above)will help with the diagnosis. Run an inline fuel filter too!

[barnett468]

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if the plug has a dry, black, coating, it is pig rich on the main jet at the very least and would warrant going down 2 sizes and testing that.

the compression greatly affects jetting, so if you change the compression by very much [more than around 10 psi], you will need to change the jetting if it was properly jetted before the compression increase.

[6spdls1z28]

The top end has been done back to stock has lots of compression. Also there is no fuel mix screw on the outside of this carb. Only idle.

[6spdls1z28]

I'm going to take it apart and pull plug will post pics.

[barnett468]

The top end has been done back to stock has lots of compression. Also there is no fuel mix screw on the outside of this carb. Only idle.

it does not have a lot of compression, or lets say nearly as much compression as it should have if the head is stock if you are at 5000 feet, it's simply impossible . . only a high quality gauge will tell you exactly what it is . . if the compression is low, that particular bike will NOT want to idle very well at 5000 feet . . i know this for a fact because i am the person that did ALL the development testing on it for Kawasaki motors.

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[6spdls1z28]

Sometimes when i kick it on compression it won't go down so I'd say its got good compression.

[6spdls1z28]

Educate me on which jet is which one says 260 and the small one with the holes on the sides says 585

[6spdls1z28]

Never mind big is main small is pilot. I understand what you are saying about the elevation though. Im not to concerned about the idle just the top end bog. I misplaced my spark plug wrench this thing is a pain to pull out with a regular wrench with the pipe in the way on one side and the radiator hose on the other.

[John_Neary]

top end bog and wont idle says air leak in my exp, can you take this to a local shop and have them do a pressure test?

air leaks can easily cause an engine seizure so careful how much you ride in till you solve this

[barnett468]

Educate me on which jet is which one says 260 and the small one with the holes on the sides says 585



ok, the stock main is a 270 and the stock pilot is a 35 for an 86 model . . the 8 you see might be a 3 . . anyway someone has changed the main before at the very least.

eres a supplement manual for 86.

http://www.oscarmayer.net/atc/manuals/Kawasaki/1986_KAWASAKI_TECATE_SUPPLEMENT.pdf
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[barnett468]

Never mind big is main small is pilot. I understand what you are saying about the elevation though. Im not to concerned about the idle just the top end bog. I misplaced my spark plug wrench this thing is a pain to pull out with a regular wrench with the pipe in the way on one side and the radiator hose on the other.

ok, well without further info including the spark plug photo, all e can do is guess so one option is to try smaller main jets and if it gets worse try bigger main jets.

also, as john mentioned, a leak down tests would at least definitively determine if it does have an air leak, however, if the plug is dry and black, it likely does not have an air leak . . also a leak that is severe enough to cause a bog on top end should cause other obvious problems but you wont know for certain unless you do one.

besides, its a kawasaki, not a honda, therefore it couldn't possibly be an air leak . :lol:

[6spdls1z28]

It bogs very little highly doubt it's an air leak the motor has been recently done. Gotta be jetting.

[John_Neary]

the spark plug will tell the story but right after a rebuild is the very time you first suspect a air leak, its rebuilds that cause air leaks in the first place :)

[barnett468]

It bogs very little highly doubt it's an air leak the motor has been recently done. Gotta be jetting.

can you explain in more specific detail exactly what it does and when it does it?

also, does it initially burble and sputter upon opening the throttle or does it just seem like it runs out of gas for a second and then accelerates smoothly the rest of the way to peak rpm?

[roll on 3]

I had this same problem when i installed my DG pipe on my 87 tecate, got it to run good and rev out, but could never get the pilot rite. put a pwk on it problem solved?
Also had same issue few years later and was a weak stator.

[6spdls1z28]

It hits hard all the way just feels like a slight miss at very top in. Only did it very little maybe running out of fuel. It runs amazing it's only started doing it since the pipe install.

[just ben]

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try spraying flammable brake cleaner gently around with the long nozzle that comes with it.

try adjusting the fuel mix screw 1/3rd at a time.

take a compression test.

your elevation is pretty high so this could be contributing to the problem . . you loose around 4.5 to 5 lbs of compression for every 1000 foot increase in compression so if the stock compression on the tecate was 170 at sea level, you would have around 130 to 135 at 5000 feet which is around a 20% decrease which is huge . . if you have compression loss from worn rings, it will only add to the problem.

if you never ride it much below 5000 feet, i would consider having the cylinder head machined to try and increase the compression.

unike the honda atc250r, the tecates were designed as a high performance bike, and in general, high performance vehicles just don't like to idle . :lol:
Fuel mix screw? I thought you helped design the t3? There is no mixture screw

[Red Rider]

By "design", he means he pulled a KX250 motor off the shelf then reverse-engineered an '85 250R chassis to house it. :p

[barnett468]

It hits hard all the way just feels like a slight miss at very top in. Only did it very little maybe running out of fuel. It runs amazing it's only started doing it since the pipe install.

yeah, that pretty much narrows it down to jetting . . your first post calling it a bog made it sound like a big problem.

[barnett468]

Fuel mix screw? I thought you helped design the t3? There is no mixture screw

Yes I had them redo maybe 60 percent or more of the 1986 prototype model to my general and sometimes specific specs while I was still in Japan testing it because it was far from acceptable for the target market, and that prototype model DID have a fuel mix screw just like every other protype carb did.

After I determined the final jetting for production, they switched to the other carb using my jetting specs . . We never received a regular full production model to test . . Also, after jetting a zillion different carbs on a zillion different bikes, some of the details can become a little blurry 30 years later.

All the vehicles had to meet a minimum standard for idling performance, however, the higher performance the vehicle was, the lower that standard was because there is little to no need for an off road high performance vehicle to be able to idle, therefore, since the Tecate was intended to be a high performance vehicle, but not an all out race vehicle like a KX bike, it was still required to idle but it was not required to idle as long or as well as a KLT or Honda AtC250R, both of which will likely idle just fine until they run out of gas because they are both obviously much lower performance vehicles than the Tecate.


The basic parameters for the idle on all the kxt models were the following.

1. Must idle for at least 3 minutes at or below approximately 2000 feet of elevation.

2. Must idle within a certain rpm range.


The ideal would be for it to be able to idle smoothly and consistently at relatively low rpm all day long, however, when one is making the most powerful 3 wheeler in the world, some sacrifices and exceptions must be made . http://www.freesmileys.org/smileys/smiley-laughing013.gif



i

[fieldy]

What was the elevation where you tested the protos in Japan, Barnett? Only curious....

[barnett468]

By "design", he means he pulled a KX250 motor off the shelf then reverse-engineered an '85 250R chassis to house it. :p

Actually, the FACT is that both the first AND second gen Tecate were designed without a Honda anywhere in sight . . The first prototype chassis was designed completely by hand without the aid of a computer by just one Japanese engineer whom Kawi Japan sent over to out facility specifically for that purpose and id I remember correctly, he was a motorcycle engineer, and definitely not a 3 wheeler engineer.

The entire program was designed with one main goal in mind which was to win the ATV National Championship, which we obviously did . . There was absolutely ZERO concern for the novice rider in the Tecate's design, [as there obviously is in the Honda ATC250R's design] just like there is zero concern for a novice rider when the KX bikes are designed.

In fact, the total amount of riding time spent comparing the ATC250R to the Tecate was probably around two weeks . . The total amount of time spent copying the Honda was absolutely ZERO [except for the red plastic apparently, :lol:], and there would have not been any point to doing so since unlike the ATC250R, our bike was aimed at the highly skilled rider and high performance market.

I have readily acknowledged on a few occasions that stock for stock, the Honda is in FACT a FAR better trail bike, and FAR easier bike to ride, than the KXT, but again, our target market and goal was simply different than Honda's.
.

[barnett468]

What was the elevation where you tested the protos in Japan, Barnett? Only curious....

I did an initial 30 minute test at the factory which was very near the coast and maybe around 50 feet above sea level . . After that, the remainder of the testing was done at their private track which was on the top of a small hill that was maybe a couple hundred feet above sea level . . I was there for two weeks . . None of this was carb testing because they already had it jetted well enough for the test . . The main carb testing was done on that same vehicle later in the US and was continued on the next prototype they sent us and it was all done below around 2000 feet . . A lot of it was done near Palm Springs in the sand and at Saddleback Park.
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[fieldy]

The pictures of Japan I have seen in the past are very rugged and mountain terrain so I couldn't gague the elevation. Thank you...... And do you know if the Kawasaki plant you were at was effected by the sunami ?

[barnett468]

The pictures of Japan I have seen in the past are very rugged and mountain terrain so I couldn't gague the elevation. Thank you...... And do you know if the Kawasaki plant you were at was effected by the sunami ?

there are a lot of smaller mountains and flat land is at a premium, and of course they have the big mountain also . . we drove by miles of rice fields on the way to the track and there were women out there picking rice by hand.

i don't know if they were affected by a sunami but their location would probable protect them pretty well.

This is exactly where I was . . i met kent howerton at the plant also, so he and i went to the city of Kobe on our day off and bought some music equipment then had some Kobe steaks..

http://global.kawasaki.com/en/corp/profile/network/akashi.html

Here’ some info about them . . They are a division of Kawasaki Heavy Industries which also has a steel, and aviation, and aerospace division, and is the biggest ship builder in the world . . In Japan, Kawasaki is probably 10 times as big as Hinda…or Hoonda…or whatever that other company’s name is.

http://www.kawasaki.com/About/HeavyIndustries

[El Camexican]

the spark plug will tell the story but right after a rebuild is the very time you first suspect a air leak, its rebuilds that cause air leaks in the first place :)

I can't like or thank posts, so LIKE AND THANK.

Do the pressure test, it is an investment in your sanity. Once your engine passes that test you can focus on compression, carb and electric, but if you assume it to be good all you are doing is closing your eyes and chasing your tail. This usually results in your head ending up in your ass at some point. Same goes for the compression test. All a stiff kick means is that your connecting rod isn't broken. A base line compression reading noted inside your tool box is a must have for any high performance two stroke owner, it's how you will monitor the health of your engine as time passes.

If you don't have the tools or the knowhow find a shop or buddy that does.

[6spdls1z28]

Son of a trailprotrailprotrailprotrailprotrailpro! My top end is leaking

[John_Neary]

small air leaks are more common than you might suspect after a rebuild and they can happen to anyone, even the best engine builders in the world must recheck for leaks after tearing down an engine

i read this from Harry Klemm, one of the most experienced 2 stroke engine builders alive, before working on my Rotax engine and it opened my eyes as to how air leaks should be treated and to always suspect one is present after you have worked on your top end

http://www.klemmvintage.com/airleaks.htm

Also some good info here from Duncan Racing- https://www.duncanracing.com/TechCenter/2stk_presstest.pdf

[6spdls1z28]

Im just glad i posted this here and you guys got me thinking about it. I had plans to take it out this weekend. So glad i found the problem before i killed the engine.

[barnett468]

Im just glad i posted this here and you guys got me thinking about it. I had plans to take it out this weekend. So glad i found the problem before i killed the engine.

ok, so why don't you tell us exactly how you determind it was leaking and also tell us exactly what is leaking.

[barnett468]

Son of a trailprotrailprotrailprotrailprotrailpro! My top end is leaking

This is actually not a big surprise, because it seems that no matter just how much one tries, when you have an engine with as much unmitigated power per cc as "The TECATE...The Worlds Most Powerful Three Wheel." has, it's extremely difficult to keep it fully contained . http://www.freesmileys.org/smileys/smiley-laughing013.gif
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[6spdls1z28]

"The TECATE...The Worlds Most Powerful Three Wheel."

Just curious why you keep saying this I've noticed in other people's threads too, then doing this:lol:

Anyway I was kicking it over slow and was hearing a hissing sound I sprayed some water on the base of the top end and it was bubbling.

[barnett468]

Have you tried to tighten the base nuts?

Some base gaskets are thicker than others so if you have a thin one a thicker one might seal.

Its possible the cases or cylinder has is warpet slightly but that would be very unusual.

There also might just be a gouge or something in one of the surfaces.
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[El Camexican]

Spray a 50/50 mix of water and dish soap around the base of your cylinder and the cases around the crankshaft area and kick the engine over a few times. You should see some bubbles forming where the leak is.

If the leak is where the two case halves meet under the cylinder you will have to lift or remove the cylinder and make sure that there is no case sealant protruding, or a void from a lack of sealant between the cases. If the cases use a gasket it may be slightly proud, so you'd need to trim it with a razor. Also make sure that the case halves aren't stepped (one higher than the other) If they are you'll need to split the cases to make sure that there isn't a dowel pin missing and if not you need to get the cases machined as a set to get them matched. I'd recommend putting a very thin smear of case sealant between the cases and the base gasket where the case halves meet no matter how they are sealed.

If the leak is anywhere else check that your cylinder nuts are torqued to spec, but don't reef them down beyond say 10% more than what is specified in your manual. and make sure all are torqued equally. If that doesn't do it make the center of leak area and remove the cylinder.

Once it's off the cases look for a high spot on either mating surface where the leak was. A piece of old gasket that didn't get removed prior to assembly counts as a high spot. If it's on the cylinder take a 3/4" of 1" wide flat bast*rd file with a very fine cut pattern and VERY carefully lay it flat over the high spot and slid it gently across the surface. The high spot should be knocked off after one or two gentle passes. You will feel a change to the resistance of the file as soon as the nick is gone and the file is contacting aluminum on the bulk of its surface, stop filling immediately!

If the high spot is on the cases stuff clean rags around the rod to seal the area off and shoot a little WD-40 onto the rag so that any crud sticks to it. Same process as cylinder after that. If you ever need to clean the entire surface of the cases or cylinder you can wrap the same file with fine grit sand paper (600-1000) and clean it up using a cross hatch pattern.

If none of the above checks out and the leak has no visible reason to exist you can try a thicker base gasket as mention, or you can use the same one you had and smear a thin layer of case sealer on the surface of the cases and the cylinder and then put the base gasket back on and assemble it. Just keep in mind that a thicker gasket drops compression.

Whatever you do make sure you test it again. If it still leaks you likely have something warped (doubtful) and will need to find the defective area and get it resurfaced.

[nd4speed]

I had to use Permatex High Tack to seal my base gasket on a LT250R where the case halves came together because of the miss match. It got so bad the base gasket sucked in ward in that spot. Never had a problem after using sealant. Even put a NOS RM cylinder on it without issue. A broken thrust washer killed it.

Leaks happen.

[barnett468]

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I suggest you post photos and a description of the area the leak is in after you get it apart . . this way someone might have a good plan of attack for your exact problem although the suggestions el camexican made in his lengthy Barnett style post pretty much cover it all. :lol:

Sealer like the aviation type sealer mentioned by nd4speed or silicone sealers like permatex black rtv gasket maker or the right stuff or toyota gasket maker 103 will most likely seal it along with a thick gasket it yours is thin, but this is really just a band aid that addresses the symptom but not the root cause of the symptom . . i prefer to fix things properly but that is not always easy or inexpensive.

If it is caused be a misalignment of the cases for whatever reason as el camexican mentioned, this means that the gear shafts and crank are also slightly misaligned and should be corrected.

[John_Neary]

my Dad always used Gasgacinch on our paper gaskets and i cant ever remember one having a leak and we did a lot of rushed rebuilds after an engine failure during a race weekend that i cant think we had perfectly clean and level case and cylinder gasket surfaces half the time

but it does make for quite a chore to clean it off when the times comes for the next rebuild...and you gotta use muscle to get the cylinder off the cases (usually the gasket rips in two) because its a pretty hardcore glue...but it will be sealed

[6spdls1z28]

Alright so i already tore it down what i found was the two back base bolts were hand tight on and pretty much blew the gasket out on the right side of the motor. As far as the cases its all in line good. I already ordered a top end gasket kit.

[John_Neary]

you likely had some overheating going on when you ran the motor and had the top end bog (that bog was it running lean because it was sucking in extra air) so you should consider checking the reeds and piston and piston ring for damage from the heat

the reeds are easy to check, just make sure they are fully closing, the piston just look for visible damage on the side skirt and the ring you should replace anytime you already have the top end off and the bike has been run...also look to make sure there is no scoring on your cylinder lining and your top end bearing could also have suffering if things got hot and should get replaced

[6spdls1z28]

As far as piston, rings, and cylinder they look perfect still. But the reeds might need to be changed.