Semi cold exhaust pipe

[Cabreco]

Quick question.

I was riding Fiona today after not using her for almost 2 weeks. She sounded funny.
When I got home after a 1/2 hour ride,  I decided to touch the pipes close to the head (it felt like it was running on 3 cyl)

3 of the 4 pipes were unbearable hot, but the 1st pipe on the left side was tepid. I poured seafoam in the full tank & revved a bit & it seemed to sound better.

Today I took her out again for 30 minutes & she still sounds odd. when I got back, again 3 of the 4 pipe are untouchably hot. The same left pipe is warm/hot. I can put my bare hand around it & NOT get burned.

I checked for spark & I have spark. I also disconnected the spark plug wire & that was noticeable. She didn't want to run. SO....

What do you guys think? clogged carb? weak spark & maybe I need a new TCI?

[TOOLS1]

Check the temp of the pipe with the engine revved to 3500 RPM for a minute. If it gets hotter, you have a plugged pilot jet.
TOOLS

[Cabreco]

I can tell you that it does get hotter (not flaming hot) but hotter than at idle.

So is this something that Seafoam may clear up, or will I have to tear open that carb?

[TOOLS1]

50/50?
TOOLS

[Cabreco]

TOOLS1 wrote

50/50?
TOOLS

Well then I will run this Seafoamed tank & hope for the best...if not, Fiona will need to be torn down, for the 1st time. :P

[TOOLS1]

Sometimes you can just remove the float bowel, and poke a guitar string through the jet.
TOOLS

[Cabreco]

Fiona is feeling MUCH better!

After you last message Tools I decided to fill the tank & dump 1/2 a bottle of Seafoam in Fiona.

I would start her up once a week & let her idle for about 5 minutes or so. She would still sound wierd
& backfire when I would snap the throttle. The 1st pipe on the left would stay "tepid" at best while the other 3 would singe the skin off you. I would also pull the plug wire off & she would REALLY run bad (so spark was never the issue)

Well, here we are March 7th. Almost 3 month since I first saw a problem. As usual, I fired her up & let her idle. I cracked the throttle and as usual, she backfired & popped. I took a quick ride around the block & she was CRAP.

I went inside, since it's 34 degrees outside & left her running at 1500 RPM to chat with the wife.
All of a sudden I here a "Change" in the pulse of the exhaust & she climbs RPMs.

I go outside and the first thing II notice is SMOKE. She is billowing smoke from the left exhaust pipe like    
a two stoke with bad rings that just blew a head gasket.

But she SOUNDS right! I feel the 1st pipe & it is now hot. I lower the idle set screw. crack the throttle a few times...no backfire, & SHE SOUND GOOD! But she is billowing smoke like a diesel!

I kept her running 10 more minutes and then took her for another quick ride around the block...MUCH MUCH BETTER!!!

Back to the driveway & to idle. smoke is now minimal & getting less & less.
Bottom line... SEAFOAM  & TIME cure a multitude of carb issues!

I guess Fiona had cabin fever & wants out in spring!
So since Seafoam fouls plugs, she will get a new set along with an oil change for he spring maintenance.

Anyway, thought I would post this not only to emphasize the benefits of Seafom to new members but to thank you for you help!

[Rockwork]

Sounds like going in and chatting with the wife was the solution... I will try that next time.

[shinyribs]

Rockwork wrote

Sounds like going in and chatting with the wife was the solution... I will try that next time.

[Ray]

I had a poor performace on Red and  put in fresh fuel with seafoam.  was better but not up to snuff. . Friend told me to try Iridium plugs.   WHAT A DIFFERANCE.  cLEARED RIGHT UP AND NO PROBLEMS SINCE

[RodneyCB750K1979]

Run a compression check. Could be valves.   Dirty seat or clearance adjustment    Change spark plug would be another thought.

[Cabreco]

Compression is good. Could be valve adj.   She only has 25K but I'm sure a clearance adjustment wouldn't hurt. I will be changing the spark plugs (even though they only have one season on them) since Seafoam, especially as much as I put in, will foul the plugs badly. Smoke issue cleared up as well.

Took her our for a ride today...I mean a REAL ride. She is back, fast as ever.
I pinned the 85mph speedo & kept on accelerating a lot more. I would say I hit 110+ before my va-J-J kicked in & I realized THIS AIN'T MY TOURING BIKE! & backed off it!

[Re-run]

Yep, sounds like a mildly plugged jet. Seafoam is the real deal. It can't fix everything but it is always worth trying. I would check your valves though. Standard check mileage is like 2500 miles or something like that. I have to admit I don't do it that often though. I do probably once a year.

I have heard good things about iridium plugs. My only question is if people have left on the stock plug caps, or found zero resistance caps to use, since the iridium plugs have built in resistance.

Oh, and if something like this happens again, a common trick is to move the 1 and 4 plug leads and plugs, and see if the issue moves. If it does, then it is spark. If not, then it is fuel. Helps a person narrow it down if they don't have a temp gun, like me.

[Cabreco]

Anybody have a good write up on valve adjustment? Pix would be helpful too

[Cabreco]

FINALLY got around to it.  Gee, I wonder why my #1 exhaust pipe on my CB 750 was tepid when the other 3 were lava hot? hmm?  
 DUH!