December 28, 200421 yr I have a 97 Techno that has no response/ power. It runs like a Reflex (TLR200) with some top end. It runs consistently and does not knock or ping even when climbing a very long steep hill. (but did spit out coolant) I bought it not running with electrical problems and do not know it's history. The carb has had multiple cleanings (27.5 pilot, 140 main, 5C23 needle in mid position). I did follow the Billy T float set suggestions. Compression is 155 psi. (The same gauge reads 150 psi on an almost new Sherco 2.9) I cleaned the whole exhaust system and it did not smoke much on the long hill. The reeds look good. I just did an air pressure leak test and there are no leaks. Any ideas on this?
December 30, 200421 yr Just a thought, have you checked the sprokets are the right ones. The drive sproket can make a hugh differance if it is to big, it is an 11 (I think) with the back 42. I did a slight mod to the carb spring on mine and it made a hugh change to the power delivery, oh yeh, I cut off about 3/4 of a turn from it. Don't know if this helps but good luck
December 31, 200421 yr Check your timing. Lots of people soften up their power delivery by retarding the timing. If I remember correctly, my former Techno ('96) ran well with the stator plate slots centered on the fixing screws. Your jetting is in the ball park. If the problem was jetting, it would not run cleanly, but it would still make lots of power (if this makes sense). Let us know what you find. -Ron
January 1, 200521 yr Author The electrics were in a box due to a non functioning fan. I replaced the rectifier, fixed a broken fan wire and remounted the stator. I found the timing spec of 2.7 mm btdc. Does anyone know at what RPM this specification should be met? Using a dial indicator and then timing light, it is at 2.7 in the mid rpm range.
January 1, 200521 yr The 'slow to return to idle' symptom has me thinking like colly on this one - maybe the air screw needs some attention - check the second post on this link: http://www.trialscentral.com/forums/index.php?showtopic=2182 My air screw is about 1.25 turns out - that is, gently turn it in until it lightly seats and back it out 1.25 turns. But really, follow the setting suggestions on the link - second post.
January 3, 200521 yr Author I finally pulled the top end apart. The bottom of the piston in front of the exhaust port has a little crack and the piston is curled slightly inward for a height of about 0.150". At TDC, there was a leak from the crankcase to the exhaust port. I guess this disturbed the gas flow. The cylinder, crank and cases are without damage. It looks like mechanical damage....like someone stuck something in the exhaust port and then tried to kick the engine over. Weird! I have pictures for anyone into these types of things. The timing never did retard. Idle was about 6 degrees BTDC. Mid was 20. When the motor really screamed, it shot up to 25 or 30 degrees.
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