Search results

There's a guy that discusses how to jet and tune pods with cv carbs (on a cb550 but concepts still apply) and does a great job breaking it down. Also, I'd check your ignition timing and advance. Do the weights move freely? For me the biggest issue didn't turn out to br carbs at all, it was the...

Thanks! I'll give it a try tomorrow and see what happens!

I know they can be tested, I've done it before with my xs750, but I'm not sure what exactly to test between, what the resistances should be ect. I've got a manual for the cb but it doesn't have anything about testing coils in it. It just says, if no spark, replace coils....thanks Clymer...super...

So I adjusted the valves on the middle 2 cylinders to be as close as I could get them to the outer 2 and a few did need adjustment and I gained a bit of compression but still no luck. The guy that owns it brought spare coils he had to work so ill try those tomorrow.

Yeah aside from valves, I'm running out of ideas too.

I adjusted them once already, that's why it has compression at all to begin with, but maybe it's off just enough? That's the only thing I can think of. When it runs great on 2 of 4 and there's no other differences I can find.

It was only running on 1 and 4 regardless of which coil, wires, and plugs I used in each cylinder.

It's gotta be valves right? Carbs are clean and the middle 2 cylinders are consistently not firing regardless of which coils are on them. The only thing I can think of was maybe the valves are out of spec even though they have the same compression as the running cylinders?

Same story. 1 and 4, no 2 and 3.

So now I'm not so sure. Came back and just to see, I did the same let it idle, pull plug wires and see which cylinders make a difference test, and same thing. 2 and 3 made no change, 1 and 4 were it. Tried to start it with only 2 and 3 plugged in (1 and 4 unplugged) and nothing. Choke on or off...

So went through the 2 middle carbs again and found a clogged tube under the pilot jet! I was thinking it wasn't removable like my wife's cl350 but wrong I was! It's still not great though. Sounds like it's running a whole lot better but it's just got no go. Topped it out at 71. Best yet but even...

Maybe 3 or 4 at most. I've just been riding it around the block after adjustments.

I've also put new plugs in it since then which are I think too new to tell.

All 4 look pretty lean but I haven't run it much and the guy that owned it before my friend had like 45 pilot jets in it or something really low like that.

Yeah I've always had spark in all 4 no matter what. When I covered either of the carbs (2 or 3, couldn't really do both at the same time) whichever cylinder I was covering would kinda come on for a sec, then flood out pretty quick and the bike would die. And like I said, the bike started revving...

Yeah unfortunately, neither are an option here. And the weird thing is, I can see the slides all moving up and down if it's sitting there in neutral with no air filters on. Also, I put my hand over the carbs for 2 and 3 while it was running just to try something and force fuel through (good ol...

All the slides move up and down freely, checked that yesterday.

Last I checked the jets look good, all new stuff. 72 pilot, 112 or maybe 115 main.

I thought maybe fuel flow too so I cracked the drain screw on all 4 and they all had gas leaking out as soon as I got about 1 turn out. Not to say there still couldn't be a blockage but you'd think if that were it, cylinder 4 would be down too.

Could this be a carb sync issue? I noticed at idle with the filters off, the slides for 2 and 3 bounce up and down quite a bit and the ones for 1 and 4 don't. All 4 come up when you rev it and none of them stick but those middle 2 are kinda bouncy.

It's always had spark in all 4.

I can double check it but it does have spark in 2 and 3 and I checked the ignition timing on 2 and 3 as well and that's on too.

Ok so I finally got around to replacing the spark advance unit and that all went fine but it's still not running on 2 and 3. Checked timing with the light and it's dead on for both sets of cylinders, it's got 150 psi of compression in all 4, I shimmed the valves so that should all be good (thus...

Yeah it's weird. So about a week ago, I did the test where you let it idle and pull one plug at a time and see if the idle changes to determine if that cylinder is making a difference. They all were, one less so than the other 3 but still. I tried it today and the bike died when I pulled...

Would a busted ignition advance cause the weird no rev issue? Just found these pieces loose behind the cover.

So I've messed with taping up the pods and can't seem to get it right now. The bike seems like it floods out and still won't rev out. Is a 120 main too much for the main? I took a video but apparently it's too large of a file.

Will do! Thanks man

Oh that makes perfect sense! I can't go back to the oem air box, it's my friend's bike and it's got a pretty aggressive cafe bike look to it. But I could definitely tape up the filters a bit to see if that does it. How much of the filters should I tape up to start? Like half?

Hey guys! So I'm working on my friends 81 cb750 and running into some really weird issues. I've adjusted the valves, rebuilt the carbs, put in a new starter clutch, and done some electrical work on it. It's got good spark, at least 150 psi of compression in all 4 cylinders (the highest is like...