Guest motorheadbob Posted February 25, 2004 Share Posted February 25, 2004 After finnishing my winter tune ect on my 2002 LeMans im getting a bad missfire at low rpm[3000+below],I tourqued the heads,adjustd valves to .006in and .008 ex[checked twice to see if i screwed up] changed plugs set tps to 150Mv with fluke,set idle at 525Mvolts resulting in too high of an idle and backed up to 1200 rpm idle and @350 Mv ballenced side to side with merc sticks set bypas screws to 1/2 turn out,can see left cyl pulsing slightly in the merc stick Will run through the gears ok but at small throttle oppenings it pops spits and other terrable things.So far ive checked all wire plugs,compression 150,155 replaced gas with new.What have i done ,going to Daytona for bike week Sat and my bike will barely run,Any ideas will be greatly aprecceated No local; dealer to help. Link to comment Share on other sites More sharing options...
RichMaund Posted February 25, 2004 Share Posted February 25, 2004 Take a look at the coils. Where the spark plug wires go into them there so much other stuff interfering there that they can get smashed to one side and pulled out of their connection. That can cause a mis-fire as it weakens the spark to have to jump the poor connection. I have also found that if a plug mis-fires for whatever reason, it fouls enough that it will continue to mis-fire even if the problem that originbally caused it gets corrected. Keeping new plugs handy solves this. One last easy check. The vinyl intake boots can crack and leak air. This will lean out the mixture on that side and cause mis-firing. Loosen the clamps on the boot and work it loose and rotate it 360 degrees and visually inspect for cracking. Flex it a bit to make any cracking show up. Hope this helps! Link to comment Share on other sites More sharing options...
docc Posted February 25, 2004 Share Posted February 25, 2004 One simple approach is to add more air to the bypass. one full turn seems to really smooth out the lower revs and idle. Best of luck but don't think we're feeling sorry for you being off to Florida and all! Link to comment Share on other sites More sharing options...
Guest motorheadbob Posted February 25, 2004 Share Posted February 25, 2004 Thanks guys,ive removed the tank and checked the coils visualy and inserted the plug wire in all the way{ill remove coils today and look closer,and check control wires}My intakes do show cracking,ive sprayed oil on them whill running and checked for smoke or change,nothing.The bike was running fairly well last week before i started this.Ive also tried different bypass setting with no luck.It must be something ive done.i also resealed the camshaft position sensor in the front cover due to slight leak i didnt remove all the way just lifted up@1/4 in and put alittle silicone seal around flange and put pipe seal on screws.Ill also try to ballance and set tpi to specs but i realy dont think that is it. Thank in advance for any ideas! Bob Mulligan in Toano VA. USA 2002 Lemans Link to comment Share on other sites More sharing options...
Guest motorheadbob Posted February 25, 2004 Share Posted February 25, 2004 Today iremoved coils,checked resestance values[same both sides]swaped coils/leads/plugs side for side[no change]removed Powercomander[no change]removed cam position sensor and cleaned[no change]checked contenuity of tps wires[ok]reset tps to 150Mv thottle plates closed,went through ballancing,runs real bad at recomened tps Mv of500/525 backed off to @ 300 and ran but still missfires/bacfires on left side.Im bummed,anyone want to buy a Lemans? Link to comment Share on other sites More sharing options...
Murray Posted February 25, 2004 Share Posted February 25, 2004 Checked for manifold /vacum leaks or exhaust leaks? Link to comment Share on other sites More sharing options...
emry Posted February 26, 2004 Share Posted February 26, 2004 I'm confused, are you adjusting the TPS by changing the idle stop screw???? I hope you are adjusting the TPS using it's adjustment slots, then adjusting the idle stop screws, (yes there are two of them) then rechecking the TPS? You have to get this sorted!!! Your bike has to be running good so all of the people on Harleys will have something to be jelous of Link to comment Share on other sites More sharing options...
Guest motorheadbob Posted February 26, 2004 Share Posted February 26, 2004 Yes,i adjusted tps with throttle plates closed by rotating in the slotted holes,then the stop screw to500Mv but idle was way too fast had to back off some so it wold idle.Mabe if ifind what is wrong ill be able to go with 500MV.But tps adustment isnt my big problem its something on left side,today im going check if possibly if i buggerd something up during head torque/valve adj.Possible the pushrod not seated corrctly?After that all i can think of is the left injector itself,anyone know how to check for bad injector??Help,id hate to have to ride a Honda[never broke] Bob Mulligan 2002 Lemans 99 VFR : Link to comment Share on other sites More sharing options...
Mal Posted February 26, 2004 Share Posted February 26, 2004 motorheadbob this may be daft but I had a similar problem on one of my old Guzzi's, after loads of messin about it turned out to be one of the new plugs I'd fitted, I put back the old spark plug and it ran beautifully (for a Guzzi) - just a rare duff new plug. It would be great if it was something this simple - worth a try. Mal Link to comment Share on other sites More sharing options...
callison Posted February 26, 2004 Share Posted February 26, 2004 Sounds like some of the symptoms my Sport 1100i was exhibiting prior to it's disassembly. I've had the bike back together for a week now. It runs, but initially it ran horribly. Idled at 2000 rpm, no oomph between idle and 6000 rpm. I put a used TPS from another bike on it and the idle dropped to normal, the throttle works properly and electrically, all is well. So... the best suggestion I can offer is to change the TPS unit. As far as the Bugswatter goes, the EFI is of course, horribly misaligned for a ported engine, but a series of things have to happen before I can start optimizing the EFI. The coils for the dual plugs have been on order since last November and have not yet arrived. I have yet to order and assemble the O2 gauges for the wide band sensors I've bought so that I can start working with the Cliff Jeffries computer etc. Eventually, it will be complete, but not in time for the Prescott Rally, much as I would like it to be. And... as far as the Prescott Rally goes, that's the same weekend that Craig Chaquico is playing at Yoshi's in Oakland, Ca. and I'll probably opt to go to that instead. Link to comment Share on other sites More sharing options...
Guest motorheadbob Posted March 8, 2004 Share Posted March 8, 2004 Just returned from Daytona bike week,last sat before i left i pulled intake manifolds off and noticed that one of the gaskets was discollerd.I checked the manifolds on a piece of glass widow pane and the manifold was badly warped.I lapped it down flat made a gaket out of auto part store material sealed with sealer and it ran!Why it showed up at that time,who knowes.Bike runs ok but still gives a POP at 3-4000 cruse rpm,and one very wierd experiace of extreem surging after pulling over to ask dirrections,when restarting it ran OK again, wierd!? Thanks for advice,Bob M. Link to comment Share on other sites More sharing options...
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