i'm getting irritated

[1000dollabill]

just bought an 87 ,stock motor, k&n, fmf pipes

 

ran like poo when i picked it up. reworked the carbs yesterday cause it was running rich. it had

 

25 pilots

270 mains

needles on the 2nd clip

ran like poo and really rich

 

changed to

 

27.5 pilots

260 mains

needles on the fourth clip

ran like a scared deer still a bit rich

 

took it out today to warm it up and do a plug chop

ran fantastic. after about 15-20 minutes of running I noticed more smoke out of the right pipe than the left. suddenly backfired and had a huge powerloss and surging at wot. checked the plugs, they looked pretty good still on the rich side.. cleaned the plugs let it cool down. fired right up on the first kick and was iidling 2-3 times higher than normal. after about 20 secs it started to idle fine. still smoking more on the right than the left. gave it a turn of the throttle and it backfired. throttle was very unresponsive. turned it off and started looking for the problem. then i noticed that i had a crack in the left jug just in front of the intake (top left of square when looking at the side.)

 

would i be correct in thinking that it warmed up and the crack opened up a little, creating a leak much like a vaccum leak and also leaning out my left cylinder and creating the eratic idle and backfiring. i'm going to tig the crack and check the reeds on wednesday when i get back in town to see if that helps. anybody have any ideas? i need to get this this thing running right. also, checked compression two days ago and both cylinders were good.

[ssanddemon]

Sounds like you hit the nail on the head: erratic , high idle and backfire is a lean condition. If you can TIG, it may be fixable. Just make sure the crack doesn't keep going up into the water jacket.

[1000dollabill]

Sounds like you hit the nail on the head: erratic , high idle and backfire is a lean condition. If you can TIG, it may be fixable. Just make sure the crack doesn't keep going up into the water jacket.

369782[/snapback]

 

 

i also forgot to mention that the left pipe pings at idle

[1000dollabill]

well it wasn't that crack. crack was just on the bolt housing not through. only other thing i can guess is the carb on the left side. the threads for the slide are nearly stripped (at the top of the carb). compression was at 135 on both today. no tors, no parking brake. gonna buy the trinity 2-1 carb thursday and hopefully that fixes me up. need to get this thing running and dialed in by next thursday

 

any suggestions ideas greatly appreciated

Edited May 19, 2005 by 1000dollabill

[hamuel]

check reeds to see if there good or bad. would also check out the coil to make sure it's up to par. I thought my was good. check and replaced mine and my jetting was way off and woke up the other jug. and both ran the same and non smoke more then the other...

[bbluebanshee]

well, since it was not the crack, lets weed out a few other possibilities. Use some thread compound, like plummers tape on the carb top to see if that is the problem. If that is not then check intake boots and seals. Since the motor is an 87, maybe intake boot is tore or cracked . Then i would check base gaskets. let us know what you come up with....we will have this thing rippin by next thurs!!

[1000dollabill]

if i had a vaccum leak can i use propane to identify the leak, like a four stroke? or am i just gonna blow it up if i do that? already tried a bunch of teflon on the carb top.

[NEVER SATISFIED]

HAVE YOU CLEANED THOSE PILOTS SINCE YOU CHANGED EM? is that smoke on that one cylinder like a cold smoke or anything and when you rev it up does it run better when you get to a higher rpm

[sredish]

if i had a vaccum leak can i use propane to identify the leak, like a four stroke?  or am i just gonna blow it up if i do that?  already tried a bunch of teflon on the carb top.

371278[/snapback]

 

yes, you can use propane gas....

 

just don't light it....