neonsurge Posted February 3, 2004 Report Share Posted February 3, 2004 (edited) I'm having recurring problems with my '99 Gasser 270. The bike starts easily (first kick, hot or cold) and runs fine at low revs. However, wind it up and she coughs and splutters like a fifty-woodbines-a-day asthmatic. Main jet clogged, right? Well, last night I stripped the carb for the umpteenth time and while I did find some crap in there, the jets were basically OK. I also checked the manifolds for air leaks and all seems to be fine. Finally I pulled the plug and it's jet black with significant carbon build up. Hmm. I removed the silencer and there's a lot of carbon and oily slime in there (and I only re-packed it a couple of weeks ago). Come to think of it, it *has* been a bit smoky of late... Could it be too-rich premix? I run it at 75:1 using Ipone oil (can't remember the exact type). I've heard some guys run as lean as 100:1 - could this be my problem? All comments gratefully received! P.S. Anyone know if Halfords stock in-line fuel filters? Edited February 3, 2004 by neonsurge Quote Link to comment Share on other sites More sharing options...
alan bechard Posted February 3, 2004 Report Share Posted February 3, 2004 Thoroughly clean and repack the exhaust and replace plug. It was amazing what this did for Doug's bike, which had symptoms much like yours. Quote Link to comment Share on other sites More sharing options...
bob abell Posted February 3, 2004 Report Share Posted February 3, 2004 Sounds like my Astro van did when the catalytic converter was plugged! Quote Link to comment Share on other sites More sharing options...
neumy Posted February 3, 2004 Report Share Posted February 3, 2004 I do not think the pre-mix is too rich, but it sounds like your jetting is too rich! Try leaning out your jetting. Quote Link to comment Share on other sites More sharing options...
astrolounger Posted February 3, 2004 Report Share Posted February 3, 2004 I am with Alan and Bob on this one.Restricted exhaust flow will cause the conditions you have.Runs ok at low speed but choked down as you increase engine speed.Try the cheap fix first,burn all the spooge/oil out of the pipe.A couple of extended 3/4 + throttle fourth gears runs up a slight grade should get that goo smokin hot!If it helps some then repack the muffler. Quote Link to comment Share on other sites More sharing options...
steve fracy Posted February 3, 2004 Report Share Posted February 3, 2004 I had problems with my 02 GG Pro that had me baffled. Came down to bad gas! How old is the fuel or maybe you just got a bad batch! Quote Link to comment Share on other sites More sharing options...
beta boy Posted February 3, 2004 Report Share Posted February 3, 2004 i get a simalar problem with my beta except it only happens after it has been riden all day then left to cool and when you start it up it is fine intill you try to ride it spluters and bangs with loads of smoke but when i clean the plug it is fine again for a few weeks intill it goes black again Quote Link to comment Share on other sites More sharing options...
jaylael Posted February 4, 2004 Report Share Posted February 4, 2004 Neonsurge: I can't help but chime in here. I hate to see you suffer. Try running it with the air filter out and see if that helps. Sometime restricted or dirty air filters are overlooked. Also Gassers of that vintage are prone to clogging of the fuel screen on the side of the carb. and also fuel petcocks which become restrictive over time as the rubber washer swells up and pinches off the opening. Don't bother with trying to put a new washer in there. If you are certain the fuel flow is restricted, I recomend replacing the petcock as an assembly if it doesn't flow enough fuel. Also the needle seat in the carb (del-orto) on many gassers is too small for wide open running on the road without it starving for fuel. The seat comes as a #200 on most gassers and with the restrictive petcocks and semi plugged screen, the fuel starvation occurs on heavy throttle running. I recomend a larger seat, # 300. The sensation is like you forgot to turn the gas tap on. If you wait a bit it catches up and runs ok at light throttle. If this doesn't sound like what's wrong, (and it doesn't) the cause may be ignition related. We are all assuming you have tried a new plug? If that doesn't fix it, you may have a shorting kill button wire. Disconnect it and see if that does it. If still runs badly it gets ugly real fast and may be any one of the three components which make up the ignition system. It might be necessary to substitute known good ignition parts from a similar machine. Check all the electrical connections to be clean and tight, and make sure your plug cap is in perfect shape, not loose corroded or full of holes or water. Let us know what you find and good luck. Hope it all get straightened out, Jay L. Quote Link to comment Share on other sites More sharing options...
neonsurge Posted February 4, 2004 Author Report Share Posted February 4, 2004 Thanks for everyone's help. Since my original post I discovered that the airbox wasn't sealing properly because the screws that hold the connecting bars on at the exhaust side (the things that the cover screws attach to) were corroded and wouldn't tighten. I've replaced those and thoroughly cleaned the filter. I'm off to my local dealer at lunchtime to purchase a new plug and a fuel filter (just in case). Failing that, I guess I'll start looking at the electrics as per Jay's suggestion. I've now almost spend the equivalent of the cost of a nice '03 bike on this thing. Still, it's all educational innit? Quote Link to comment Share on other sites More sharing options...
superflytx270 Posted February 4, 2004 Report Share Posted February 4, 2004 Also Gassers of that vintage Gassers of that vintage?????????? So what does that make my '98 tx270? a relic? Quote Link to comment Share on other sites More sharing options...
jaylael Posted February 4, 2004 Report Share Posted February 4, 2004 Sorry about the poor choice of words. It isn't meant in the "vintage" sense of the word, but in the "age zone" which doesn't have as nice a ring to it. J Quote Link to comment Share on other sites More sharing options...
jrsunt Posted February 4, 2004 Report Share Posted February 4, 2004 sounds more electrical than anything else, probably the charge or pulsar coil beginning to break down behind the fly wheel. they are quite cheap and easy to replace. Or again take the flywheel off, if everything is covered in a white fungus (caused by dampness sat in there) that will also cause the spark to break down under load. Dry it all out, scrape all the ****e off and it should go. Quote Link to comment Share on other sites More sharing options...
neonsurge Posted February 9, 2004 Author Report Share Posted February 9, 2004 Just to provide a bit of closure on this one, after thoroughly cleaning the carb, I replaced the plug and air filter, drained the crankcase and changed the gearbox oil. Runs fine now. Thanks for everyone's help! Quote Link to comment Share on other sites More sharing options...
old-fart Posted February 14, 2004 Report Share Posted February 14, 2004 I had the same problem with my 98 Gasser. I just installed the correct (resistor type) plug and it would rev out cleanly. Quote Link to comment Share on other sites More sharing options...
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