Soooo, it happened again. I seized another cylinder. 4-point seizure that has repeated itself a few times since I went with the overbore. But she was running soooo sweet! Just before this, she yanked a real nice roll-on power wheelie in 2nd gear!!
Anyway, trying to figure this out, I just wanted to ask you guys: with all the seizures that have happened on this board, how many were 4- point seizures? Were you running a thermostat or not? Mine have always been WOT in 6th gear at high speed. By the looks of it, I think maybe the cylinders heated up and the thermostat burped open for a little bit and cooled the cylinders too much before the thermostat could close again. My jetting actually looks RICH on the plug, and I was riding the freeway at 60 degrees operating temp for over 10 minutes before this happened. I had the throttle at wide open for less than 10 seconds before, running around 9-10k.
So, once again, how many of you who have had seizure problems lately, including those running the Tyga 300 kit, were still running a thermostat?
And, where have you US guys had your replating done? I was thinking of using Millenium, as my luck with US Chrome has not been too good. _________________ Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS
Just got my cylinders back from Millinium and they look great. Ports relieved as well. Mine siezed on the upper but was just on the exhaust port bridge. I'm not running the termo at present but was thinking of putting one back in. Any opinions on the thermo 4 or against? _________________ To much HP is barely adequate!
damn, this is like de ja vu. Sounds like we have a lot in common Paul.
3 out of 4 of my seizures happened in the same conditions as you, WOT 6th gear for bout 10-15 seconds on the freeway. Pretty feckin hairy if you ask me. One of them was because I forgot to hookup the oil pump cable after doing a jet change. As for the other, who knowss? Cold weather on a lean setup? Poor gas? I'm just happy that its not as sieze happy anymore.
Coincedentally, the last siezure was because of a wack replate courtesy of US Chrome. I'll be trying Millenium next though. _________________ MC21 300R w/SE bits, Rossi 2001
MC28SE Silhouette Repsol
Hey Fellas,
We should start a club! End of the straight away 6th gear. I was very lucky to get away with a hone and a new piston. It was detonating so hard it broke a dime size piece of the skirt off and cracked all the way up to the oil holes!!! I heard the detonation the lap before too It was very cold, about 50 F but my temp gauge was at 70 C. As far as thermo I may reinstall mine because the tape game is getting real old. But to get to 273#'s you have to make some sacrifices. I belive my seizure was due to a jetting mistake. I have rejetted and installed E.G.T. gauges and started running race fuel which may have been a problem. Did you check your piston clearances and your ring end gaps? My piston clearances were perfect but my ring end gaps were a little tight. Upon dissassembly I found the good cylinder had a little scoring where the ring end gaps meet like the rings were running out of room. Later measurements showed they were. If by four point you mean a little alum at each corner then count me in. I'm about half way through my break in and I'll keep you posted. Just remember when you set to kill there is a fine line between fun and skidding the rear tire for 150'. I've had some issues but can you argue with the constant wheelies and being able to dial it sideways out of the corners!!! Its worth it!!! _________________ 1995 A kit TZ 250
1994 Rothmans NSR 300sp SOLD
1998 RM 250 freestyle/motorcross
1998 Meathanol burning CR 500 AF super retard/motorcross/sand dunes/play bike
Sooo,
trying to eliminate possible problems here. I did a search and cant find the info I need on checking the TPS adjustment. Anyone have the info? _________________ Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS
Wrench. wrote:Sooo,
trying to eliminate possible problems here. I did a search and cant find the info I need on checking the TPS adjustment. Anyone have the info?
As far as I understand Paul, the TPS is not a system that is supposed to be adjusted, but I believe you can test the resistance and that it's within factory specifications, according to the diagnostic section in the workshop manual. Hope that's of help. _________________ NSR300R - Why did i ever have a 250...
My last siezure happened when the cooling hose fell off. The one before because I didn't rejet when I moved from a track at 26 degrees, to one at 12.
I don't run a thermostat, but moistly cuz there wasn't one fitted when I bought the bike. _________________ MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
Not sure what type of egt but I stole it off one of my sled engines. One sides not working so I am looking for another one. Its also calabrated for 32 F so I was thinking of replacing it anyway. Anybody else running egts? Where did you mount the probes? I went with 5" from piston. Went out Wednesday and with my new jetting I was seeing 600F when I opened up the 39's. I was able to get it up to about 900 F at 1/4 throttle the same throttle setting it was at when it seized with 2 mains leaner. Is it possible to seize from incorrect needle settings??? 900 seems low but I'm a little scared. All my other 2 smokers love to run at 1200-1300 F no seizures with the probes at 6" from pistons. My TPS is WFO all the time. 030 card and minium 105 oct from hereon out! I'm going to play with the needles and air screws this weekend and then its back down slowly on the mains because the temp is on the rise around here. I LOVE jetting. Anybody have any fuel injection _________________ 1995 A kit TZ 250
1994 Rothmans NSR 300sp SOLD
1998 RM 250 freestyle/motorcross
1998 Meathanol burning CR 500 AF super retard/motorcross/sand dunes/play bike
Fuel injection would be a blessing wouldn't it? Bimota struggled so best of luck!
I guess you can sieze on needles since they do affect the ratio, if only by a smaller amount than the main jets. Jetting is a black art, and when the engines / carbs get worn, who knows what is really going on inside them? _________________ MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
I searched the Technical section, and found nothing that covers the TPS adjustment/readings.
Matt? I'm sure you have something on this.
I installed my spare set of carbs, and the Error light came on. I turned the TPS a little until it went off, but dont know if it is adjusted right. _________________ Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS
Paul - If you check out pages 19-5 & 19-6 of your 28 workshop manual, you'll see the method of testing there. It looks like the range of the TPS is between 4-6k ohms and should read between 4.5 and 5.5 volts. I think that you can take the readings without the special tool they use, just need to make up your own wires... _________________ NSR300R - Why did i ever have a 250...
I dont have a workshop manual. All I have is a 28 parts manual.
I need to know how to hook up the connections to test it, and what readings I should get. _________________ Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS
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