Tecate broke again

[Tecate250]

Ever get the feeling that you should only fix things when they break. Well I just put my back breaks on,put the green tank back on after fixing a hole and got power for lights. When my bike blew up. The same way last time. But with a rebuilt crank with hot rod. Bored out to the max. It now has 150psi way down from 200. It will not run and my piston is scorged on the left side and right side. The piston does not look too bad. It might have 50 hours on it. I run 20-1 gas.
Any ideas?

[Ryan.]

run less oil... try 32:1

oh and was it a piston seizure, or did it melt?

[3Razors]

Kawi recommends 32:1 with the tecate. Was the piston to bore clearance set properly, ports chamfered, ect? A picture of the piston will help alot in diagnosis

[mdunn]

50 hours is a long time. Kawasaki recommends checking the piston and changing the rings every 30 hours. When we used to race them, it always got tore down at 25 hours. Hopefully you do not have too many problems with it. Post some pictures when you get a chance. Good luck!

[cr480r]

it still has 150psi of cranking pressure and it wont run?

[Tecate250]

Yep. 150psi. My buddy came to my house and did a compression test on his ke 100 and it had 150. The piston is not seized. Not even marked up bad. It appeares that the piston was rubbing in 2 seperate places. My book says to use 20-1 and have since i owned the bike way back when. It seems like when I put money into it, it breaks down. I wish I had a pic.I ran this bike for 5 years without putting a piston into it.

[tri-Z ripper]

well i swear by 50-1 but thats me maybe 40-1 in the summer but man 20-1 does that thing keep the mosquitos away to?:lol:

[Tecate250]

It never fouled a plug ever. And I take it in some bad ass places where this thing should not go.

[tri-Z ripper]

that is amazing i tell you does it smoke alot? i mean more then the average 2 stroke is this what all the tecate people run for a mix??

[BigGreenMachine]

Define "blew up."

Was the motor warmed up or just warming up when it went?

[Tecate250]

It was plenty warmed up when It blew. I did not even hit it. It had a rattle sound befor it blew tho.

[dizasterzrfun69]

When I hear "blow up" I imagine a piston with a hole in it, busted skirt.




thats what a BLOWN engine is, what you did john is a "fried" engine. thats just my 2 cents

[300rman]

it could be cause the motor is running too lean. what color is the plug? a tan/brown color is good. anything lighter, and its too lean.

20:1 ratio is perfectly fine. i run that on my 84 R, and it runs great, very minimal smoke.

[Tecate250]

The plug was blackish brown. But that almost looks like my piston. But both of mine look way better. I run the v force cage as well as the stock carb from a 83 kx.. Would that have anything to do with it?

[RID3R]

You say around 50 hrs, and you have run this bike for 5 years without changing the piston. I dont think you have a real problem, if its ran fine until now. Just needed a fresh topend. And I would use 32:1 not 20:1

[Tecate250]

It worked great till these last pistons. I have just done some upgrading. I thought the high compression of 200+ might have done something but didnt.

[BigGreenMachine]

Its hard for us to tell you what caused it if theres no pics.

[MIK6]

The technology in oil has come along way since that book was written. i use a good quality oil at 40/1. w/o any problems. if you are using junk oil from 1985 id run 20/1, but not now.

MIK6 / Mike

[edog]

32:1 Golden Spectro Synthetic.4 gallons of 93 octane.I would run this if I were you.

[Tecate250]

I ran synthetic oils at higher ratio with my t4 and it ran like junk. Also the price and avalability. I am starting to think it was lean with the oil on the plug giving me wrong readings.

[mdunn]

Interesting that you ran higher ratios and it ran like junk....typically if you run too much oil, that is when it runs like junk. I'm with edog...Golden Spectro Synthetic is about the best stuff out there...burns very clean and leaves no deposits.

Finally, I don't think anyone is going to be able to suggest a correct solution without some more pictures and more detailed description of what happened. There's just too many options...you mentioned you put a new piston in it...was that recently, or 50 hrs ago? I just pulled my '86 Tecate apart for a complete restoration. The piston skirt was completely cracked off at the rear of the piston and the rings stuck in the piston lands.....it still was running when I brought it into the garage.....needless to say, the motor is getting a complete rebuild, but it was still running even in that condition....

[cr480r]

check your flywheel key... even though the piston is smoked it should still fire with 150psi...

[Tecate250]

Have not tried the key way. But the top end is off it. I wanted to spend the little money I have to fix my 250r. But it looks like a new piston for me.