garyS-NJ Posted June 26, 2015 #1 Posted June 26, 2015 I'm still trying to get my bike running.. I bought it recently with a seized engine after it sat a while.. I got it idling but it would not rev without bogging and popping out the carbs. after a new set of spark plugs and doing the Pea shooter and the Shotgun, and finally removing and cleaning the carbs (I did find a lot of crud in the bowls and clogged jets in the jet blocks), it still will not rev without blowing fire out the carbs (running without the airbox, I'll try it with the airbox but I'm sure it's something else as it's just too bad). It does run better but still seems like the timing isn't advancing.. So now I'm wondering about the TCI or the Pressure Sensor that rules the timing advance in the TCI. any thoughts? I've already checked compression and leakdown so I don't think it's valve lash.
syscrusher Posted June 26, 2015 #2 Posted June 26, 2015 I don't have an answer but what are the pea shooter and the shotgun?
utadventure Posted June 26, 2015 #3 Posted June 26, 2015 Gary- With the bike running, have you looked down into the carbs and made sure the slides are moving? Checked the diaphrams for holes? Check the mixture screws and reset them out 2 3/4 turns. Turn the sync screws out so the butterflys are not adversely effected and re-sync the carbs (I'm hoping you can a high enough RPM to do it) - this is also verify that the vacuum ports on the carbs aren't plugged. Dave
Venturous Randy Posted June 27, 2015 #4 Posted June 27, 2015 A bad pressure sensor/hose probably won't give you the symptoms you are describing, but it may cause the bike to be a little down on power for not advancing. Ditto on Dave's suggestions on the sync and pin holes in the diaphragms. Randy
Flyinfool Posted June 27, 2015 #5 Posted June 27, 2015 Another thought. Since you found a lot of crud in the carbs, how is the fuel filter. Plugged? Broke and not filtering? Could there have been crud in the lines and once you put it all back together it blew all of the crud into the carbs? Just guessing out loud here?
jasonm. Posted July 3, 2015 #6 Posted July 3, 2015 Gary- NJ, you state "running w/o air box." Everyone will tell you...it won't want to run worth a darn w/o the air box.
dingy Posted July 3, 2015 #7 Posted July 3, 2015 I don't have an answer but what are the pea shooter and the shotgun? Shotgun is a method of clearing jets and some internal circuits on carbs without dis-assembly. I just did it to Tweety a couple of weeks ago and it cleared up a very annoying backfire on 1 cylinder in 3-4000 rpm range. http://vmax.lvlhead.com/tips/shotgun.htm This air gun from Harbor Freight is also very helpful. http://www.harborfreight.com/pistol-grip-blow-gun-68259.html Link to youtube video showing pea shooter. Gary
garyS-NJ Posted July 16, 2015 Author #9 Posted July 16, 2015 good input randy on the pressure sensor. I figured it just drops the advance when vacuum drops rather than causing the engine to advance with rpm. My ebay replacement pressure sensor is also 2.3v at 1atm but only goes to 0.8V at 26 inches HG. My old pressure sensor went to 1V at 26 inch HG. the manual says it should go to 0.5V.
garyS-NJ Posted July 16, 2015 Author #10 Posted July 16, 2015 oh and I already went through the carbs and fuel.
MiCarl Posted July 16, 2015 #11 Posted July 16, 2015 When you said before the timing wasn't advancing I'd assumed you checked it with a timing light. The engine will run quite nicely without timing advance, it just has no power. You're timing may be off, but it won't be the pressure sensor. It's job is to retard the timing when pressure is high (low vacuum). Incorrect valve timing can also cause it. Your most likely reason though is it's lean, and running without the air box will make it lean.
garyS-NJ Posted July 16, 2015 Author #12 Posted July 16, 2015 I'm pretty sure this bike ran at some time. The timing can't be off unless the rotor slipped or the tci is humped. and it does idle and on the timing marks so the timing is on. the PO seemed straight up and said it used to run and then he lost the clutch (leaky slave) and perhaps the carbs got gunked up from sitting. I went through the carbs. and yes, I checked timing through inspection hole. it just bounces around but doesn't advance. and the tack is sometimes erratic dropping out completely and otherwise it won't rev up (even turning throttle up slowly) past 2500 rpm without backfiring fire out the carbs. I've had the airbox on after doing the carbs (I think) and that didn't help. Guess since I'm locked up with this TCI (can't get it out yet, seems I have to pull the right and left fairings), I'll put the airbox in and try it buttoned up. I have to make some progress today just to rule that out.
dingy Posted July 16, 2015 #13 Posted July 16, 2015 I'm pretty sure this bike ran at some time. The timing can't be off unless the rotor slipped or the tci is humped. and it does idle and on the timing marks so the timing is on. the PO seemed straight up and said it used to run and then he lost the clutch (leaky slave) and perhaps the carbs got gunked up from sitting. I went through the carbs. and yes, I checked timing through inspection hole. it just bounces around but doesn't advance. and the tack is sometimes erratic dropping out completely and otherwise it won't rev up (even turning throttle up slowly) past 2500 rpm without backfiring fire out the carbs. I've had the airbox on after doing the carbs (I think) and that didn't help. Guess since I'm locked up with this TCI (can't get it out yet, seems I have to pull the right and left fairings), I'll put the airbox in and try it buttoned up. I have to make some progress today just to rule that out. If the tach is dropping out, you at a minimum have electrical and/or TCI issues. Tach runs off #2 coil circuit. Tach dropout indicates this cylinders coil is firing intermittently. Gary
garyS-NJ Posted July 17, 2015 Author #14 Posted July 17, 2015 Gary did I read somewhere that you sell replacement tci?
garyS-NJ Posted July 17, 2015 Author #15 Posted July 17, 2015 ANd BTW, with my current pressure sensor only reaching 0.8V at 26inch HG, do I need to get to 0.5V??
dingy Posted July 17, 2015 #16 Posted July 17, 2015 Gary did I read somewhere that you sell replacement tci? Yes I do. I have some available now. http://www.venturerider.org/forum/photopost/showproduct.php?product=396&title=ignitech-ignition-control-module-for-1983-1993-venture-27s&cat=20 Gary
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