Re-re-reviving my '81 Seca 750

So, when you're working on a bike you've had for nearly 30 years, it's good to trust your gut. When I said it was good, then then halfway around the block it acted up, maybe overheating? What it really felt like was fuel starvation. BUT I had plenty of gas in the tank and had even tried the Prime setting.

Was still rough this morning. Went to take the tank off to dig back into it only to discover the fuel line was pinched when I'd replaced the tank yesterday. I put the fuel line in the right place, and it fired right up and idled smoothly. Just went for a 50 mile Father's Day ride. Back in business.

And yeah, a fresh bulb fixed the turn signal situation as well.

As for sooty #4, it really was. Again, that was the old one. Interestingly, when I'd first pulled it after getting home from work on Friday, it was a nice tan. That soot was from troubleshooting - or troubleSOOTing, har - at idle. Once things cool off I'll pull the new plugs and see how those look now.

And just to wrap up (for now), the oil looks good as it's only got about 2k miles on it, but time-wise it's overdue and coming out in the next few days - thus the recent Seafoam dosing.

Oh, and I got into some cicadas on today's ride. Dodged all but two, i think - one on the windshield and one on my pant leg. Eech.

 

Glad to hear it was a simple fix

 

Got the oil change in today as well. A good Father's Day.

 

The new plugs after a 50 mile blast yesterday. So clean!

 

Bike still needs a little tweak. May e due to the plugs being at full bang potential, the RPMs were floating a bit on shifting and coming to lights on the commute today. Hadn't noticed it on yesterday's ride, but that was pretty continuous blasting. Did think throttle was not as snappy. A carb sync should solve it, I'd think. Always something.

 

Plugs may be a bit lean yet, too. Double-check for vacuum leaks at the intake boots.

 

Never circled back to this, but some VERY minor tweaking of the carb sync brought everything back in line and purring nicely.

 

Ok, just in the last 2 days, my oil light is REALLY annoying the hell out of me, so pulling the sensor for manual cleaning will likely happen sooner than I'd wanted (planned to do it this winter). Oil level is confirmed good, have tried 2 Seafoam treatments, and it still acts a fool with little rhyme or reason. It comes on with some hard accelerations, but not all. Sometimes a gentle rise in the road, or a seam in the pavement can turn it on OR off. Occasionally it's on for a flash or two, but lately it's more likely to stay on for a minute or more. Just long enough for me to get annoyed, cancel the warning, have it clear and then re-activate. Yesterday morning, it didn't come on once in 26 miles. Today, at least a half dozen times.

Aside from needing to replace the seal (which seems to be leaking anyway), my big concern is going to be dropping the exhaust, which, to my knowledge, has never been done. Do I need to mess with the header bolts, or can I just (try) to separate the header pipes from the collector (and how much damage will I do to the already-rattling collector when I do?)? I did have the megaphones off in late 2022, so hopefully those come back off fairly easily, but any tips appreciated.

 

Exhaust bolts suck, no matter the vehicle. Start spraying everything on it with penetrating fluid days or weeks ahead of time. Spray it, ride it to get some heat in it, spray again, rinse and repeat.

 

Many times, the collector rattle is actually due to the heatshield on one side or the other.... they’re welded on across the top and bottom, by there is a welded-on ring clamp at the front and back. Often one of THOSE rust through and then make an awful rattle. I just wedged a thick piece of leather in there, and I’ve also just carefully bent the heat shield out just a bit so the vibration does cause metal contact anymore.

Sometimes, the rattle is inside the collect itself, as it gets a loose rusty part, and I’ve also had rattled that are actually inside the muffler as the baffles get loose.

 

I cleared all the crap out of the mufflers and checked the heat shields when I messed with it all 2 years ago.

 

Of course, on yesterday's ride home from work, even with two HARD pulls up to 50 and 70 MPH, no oil light at all.

Make it make sense . . . .

 

They joy of an old bike. Oil level indicator is wonky, and you’re waking it back up..... or, you may have a loose wire somewhere——

 

The saying is with the Vmax - if you're not making the oil light come on you aint riding it right...

 

I have wondered about a loose or grounding wire, but ran out of time to run that down this weekend.

 

A new gremlin has appeared - not sure yet if mechanical or electrical.

When I de-mothballed the bike late 2022, I'd noticed the turn signal switch felt a bit . . . gummy. Turning it on was fin, but cancelling in the middle took more effort than I remembered. When I got back on the road this spring, I finally decided to try to degunk the switch. I didn't want to go too aggressive with contact cleaner, so I just spritzed some IPA (not the beer) in the switch and it was immediately better.

Yesterday, a new behavior was observed after months of reliability. The turn signal would only stay on if I held the switch left or right. As soon as I released it, it went off. After about half an hour, it was back to working properly for the rest of that ride. Then, on the way home, it was fine again, until about 15 minutes in when it stopped working correctly for about 5 minutes and then was fine.



Have not had a chance to take the switch apart yet, and I also wondered if it might be a fault with the auto-cancel unit. It was pretty hot when it first acted up and I wondered if that heat would prematurely cancel the signal. But when I rode home, it had cooled off considerably - upper 60s, so not putting a lot in that theory now.

Anyone seen this? It will probably be a couple weekends before I can get into the control body.

 

What happens if you disconnect the auto cancelling unit?

 

I would have used kroil, rather than an IPA.... you may have intoxicated the switch.

 

The turn signal thing, like the oil light, is VERY intermittent and very frustrating. LOL

 

Heh, I forgot the actual point of my post - what are y'all using for fuel line? I feel like I'm always wrestling with it - have tried various things from the auto parts store and I'm not sure what's on there now, but the OD seems too big for the standard clamps and the ID seems a TOUCH too tight to be able to get fully on the barb of the petcock.