Author Topic: Patina Hyena - 550/650 674cc Hybrid Cafe Build (Read 384100 times)

DaveBarbier · « **Reply #625 on:** July 23, 2015, 08:38:45 PM »

Think I'm running on cylinder 1-4 only...might just be running on 1. Tank was really low and it was sputtering, surging and popping and if I let the RPMs drop too low it would just die. I thought it was low on fuel so I switched to reserve. Didn't get better but I limped to a gas station where some kids were smoking cigarettes and there were two hot chicks...damn!

Filled up with fuel (it was really low) fired it up and it was maybe a little better but not really. I tried using the choke a bit and I think that helped but maybe not. Limped home and...well that's where I am now. I'm thinking that I just sucked some debris into the carbs and they're clogged, but it didn't get better when I gave it WOT (me thinking the mains wouldn't be clogged too so it should take off) but it could be a restriction in the line. BUT it could also be a coil or some ignition thing like crap condenser(s) or something.

Hoping that it's just debris.

Any thoughts?

DaveBarbier · « **Reply #626 on:** July 24, 2015, 09:47:41 AM »

Drained fuel into a clear wine bottle and found a good amount of debris coming from #3 and some from #2. The rest were pretty clean. Dropped all the bowls there was still more crap. #2 had quite a bit of, what looked like, ethanol separation. The kind of clearish gooey brown balls. Then turn to powder once dry. I'm going to take the carbs out and clean them more thoroughly. It was sitting for a few weeks when I was doing the dual disc conversion but didn't think that would have been an issue. Should I be adding stabilizer or sea foam to the fuel to help prevent this? Is it possible the fuel up here in CT is worse?

SOHC4 Cafe Racer Fan · « **Reply #627 on:** July 24, 2015, 10:40:14 AM »

Fuel can turn, but doesn't usually turn that quickly. I tend to place a capful of Seafoam in every new tank fill up, and I do not seem to get that problem.

DaveBarbier · « **Reply #628 on:** July 24, 2015, 10:59:35 AM »

Quote from: CB750 Cafe Racer Fan on July 24, 2015, 10:40:14 AM

Fuel can turn, but doesn't usually turn that quickly. I tend to place a capful of Seafoam in every new tank fill up, and I do not seem to get that problem.

I'll clean this out really well and see what happens down the road. I'm pretty against fuel or oil additives, asside from zinc in my oil...but if it's better for my bike then I'll do it without hesitation.

SOHC4 Cafe Racer Fan · « **Reply #629 on:** July 24, 2015, 11:05:33 AM »

Seafoam keeps fuels from breaking down into water/varnish. I have seen people cautioning against dumping amounts of Seafoam or other fuel stabilizer into fuel -- only a capful is needed.

If you remain steadfast about not using additives, then try to find a source of non-ethanol gas (harder to do here in California).

http://pure-gas.org/

DaveBarbier · « **Reply #630 on:** July 24, 2015, 02:18:05 PM »

Yeah, I might just go ahead and add some to be safe. Maybe carry a little bottle with me on the road or something too. I used that site a while back and there's one place. It's like 100+ octane and something like $15 a gallon. It's race fuel or something. Not an option. I hate ethanol.

DaveBarbier · « **Reply #631 on:** July 24, 2015, 04:49:36 PM »

Just cleaned the carbs really well with compressed air and some super cancer causing carb cleaner. Tank is flowing good clean fuel. See picture just for verification. Going to fire it up and see what happens.

DaveBarbier · « **Reply #632 on:** July 24, 2015, 07:57:26 PM »

Ok, so that didn't work. Still sputtering like crazy. I took a video and will post it as soon as it uploads to YouTube. It might be hard to hear but it shows the sputtering and surging.

I'm thinking it could still be a fuel issue in that the petcock is restricted. Like in the sock filter or something. Now, this isn't a stock petcock. It's a cheap one I got on eBay some time ago so it might not flow fuel well enough already. And now with a little clogging could really impede delivery. I'm thinking this is the case because the bike seemed to idle decently as soon as I first fired it up after the cleaning and as I rode it seemed to get progressively worse.

Any other thoughts? I'm going to pull the petcock tomorrow. Anyone know of a petcock that will work better for me? The OEM ones are unobtainium.

RAFster122s · « **Reply #633 on:** July 25, 2015, 03:30:38 AM »

If you are having fuel separation in the carbs, then you may also have it in the tank

May require pulling the tank and flushing it out to get any residual crap from the bad gas and the petcock flushed. Hopefully the brown gunk isn't the rubber in the hoses being attacked by the fuel. Ethanol fuel wasn't hose friendly, requiring a change to the fuel hoses to make it compatible.

You may need to tank the carbs to flush the passages. But, a clean of the tank and petcock should get you close to running. Test theory with an auxiliary bottle of gas serving as the tank before you clean it.
If the problem clears, you know that the tank is contributing. Of not, then you need to clean the carbs or ultrasonic bath them to clean the carbs.

Good luck,
David

DaveBarbier · « **Reply #634 on:** July 25, 2015, 05:27:21 AM »

Quote from: RAF122S on July 25, 2015, 03:30:38 AM

If the problem clears, you know that the tank is contributing. Of not, then you need to clean the carbs or ultrasonic bath them to clean the carbs.

Good luck,
David

IF it's actually a fuel problem. Which it sounds like to me it is and since you guys feel the same way then I'm pretty convinced of that. I don't have an aux tank but I'll post a video of the fuel flowing from the petcock and see if it's flowing well. And it won't take long...I'll pull the petcock anyway and flush it out.

DaveBarbier · « **Reply #635 on:** July 25, 2015, 05:31:29 AM »

Not sure if this video actually shows anything but I think it's funny.

DaveBarbier · « **Reply #636 on:** July 25, 2015, 08:18:20 AM »

Draining the tank into a gas can. Here's a video of the flow rate. Thoughts?

DaveBarbier · « **Reply #637 on:** July 25, 2015, 08:55:07 AM »

Wish the petcock was clogged. But it looks super clean. I'm now thinking that this isn't a fuel issue. Spark?

Any idea how to remove this screen in the tank? It's pushed in really good. It seems pretty clean other that that small bit of crap at the bottom.

DaveBarbier · « **Reply #638 on:** July 25, 2015, 09:22:36 AM »

Quote from: calj737 on July 25, 2015, 09:02:46 AM

Start inspecting your ignition, coils, and plugs. Are there any loose wires? Anything grounding out intermittently? Have you verified it's idling on all 4 cylinders?

Your fuel looks fine, so move on if you are confident the carbs are now clean. (You could double check quickly whether clear tube level is still where you left it).

Confident they're clean. I didn't soak them in anything or use an ultrasonic cleaner but I'm confident. I will check clear tube in a bit once the tank goes back on.

One thing that I don't think is related but I might as well be transparent, my headlight low beam filament has been blowing. Twice so far when out for rides about half an hour in length with a lot of revving. But it has happened and the bike's performance hasn't been affected at all until a couple days ago. I got a new headlight bucket and omitted the grounds to the bolts where the headlight gets mounted to the forks. I thought the main ground was good enough but I guess it's not. I put them back on and tested for continuity and it's a good ground. Haven't been able to test if my low beam blows or not since this stuttering started happening. Will check ignition. Is there a way to test condensers? Other than swapping?

I'm reading through this post: http://forums.sohc4.net/index.php?topic=89297.0 I don't think he was having the stuttering symptom, though.

When I came home the night this started acting up, the #1 header was hot. 2-3 were warm but I could hold my finger there without getting burned. #4 was...I don't really remember. I think it wasn't that hot. When I went out for the ride yesterday after the carb cleaning, it seemed like all 4 were hot after I started it. I don't remember testing the headers after I came back from the ride, though. So not sure it's idling on 4 cylinders.

DaveBarbier · « **Reply #639 on:** July 25, 2015, 09:49:37 AM »

4-3-2-1

I didn't ride today so I couldn't tell if the plugs were wet with fuel. I suppose that's another test I could do.

Plug caps, wires and coils are all in spec.

DaveBarbier · « **Reply #640 on:** July 25, 2015, 10:22:59 AM »

Power at coils is 11.93 volts with key on and kill switch to run position. (One lead to B/W wire and one to frame ground)

Both points have about 11.94 volts when open and no measurable voltage when closed. Is there a way to test condensers with the multimeter?

EDIT: Way to test condensers.
http://forums.sohc4.net/index.php?topic=104684.0

Both condensers test fine.

Any other ignition tests I can test for? I might put it all back together, run it and check timing with my light.

DaveBarbier · « **Reply #641 on:** July 25, 2015, 10:56:31 AM »

Quote from: calj737 on July 25, 2015, 10:45:40 AM

Condensers: they can test good, but fail when hot. When the bike stutters, test the headers for temps.

Plugs: 1/4 look pretty lean. 3 I like, 2 is a "tad" rich. Almost makes me think 2/3 coil side isn't firing as hot. But I'd also enrich 1/4 carb settings (my opinion). Then retest all with clean plugs and a half-to-full throttle position.

Gotta love vintage bikes $:-\$

Ah yes. I don't have an infrared thermometer so I'll just have to use a wet finger...not sure how accurate that is.

Yeah, 1/4 look lean. I'll deal with the that later on. I guess I'd have to do plug chops to figure out where it's lean before adjusting anything. Ignition first!

Thanks Cal

DaveBarbier · « **Reply #642 on:** July 25, 2015, 11:27:47 AM »

Making headway...?
All four headers are equally hot according to the wet finger gauge.

Just checked timing and 1/4 was spot on and 2/3 was dancing all over the place at idle and never made it to full advance. Reminds me of last year when I had to shim my plate which I documented back a few pages. Is that a timing issue? Or could that still be a condenser problem?

Should I just redo the timing on this or could there be something else going on?

DaveBarbier · « **Reply #643 on:** July 25, 2015, 11:44:06 AM »

Problem follows condenser! Swapped it over to the 1/4 and now the 1/4 dances like mad. Might take one off my CL200 to test it.

Oh, and they're Daiishi condensers.

DaveBarbier · « **Reply #644 on:** July 25, 2015, 12:33:31 PM »

Can't use the CB200 one. Looks like I'll just have to order a pair of TEC brand.

DaveBarbier · « **Reply #645 on:** July 29, 2015, 05:55:20 AM »

Back on the 650. Just trying to get info together for when I get going on buying parts and getting machining done.

Thoughts on carbs:
One, am I crazy for not wanting to use the stock CV carbs with pods or velocity stacks? In my limited knowledge it seems like mechanical slide carbs are better for this kind of build. Unfortunately, the heads are different from '79 and '82 and the early style 750 carbs won't workout. Does anyone know of other carbs that I could work with? I put a message into Harisuluv regarding the possibility of just changing the spacing of 750 carbs (or even my PD46c's although I'd rather not because of pitting and the bent carb mouths on #3 and 4) to fit the 650. I was also toying with the idea of getting Keihin CR carbs, but they're expensive, and I don't know if they would be delivering too much fuel even with tuning way down.

Now I could just get a '79 head but mine is in pretty great shape so I'd hate to trade it in favor of an unknown. Trying to get this figured out sooner because I'll hopefully be sending the head, jugs and upper case half out for machining soon.

DaveBarbier · « **Reply #646 on:** July 29, 2015, 03:26:59 PM »

Got a quote from Dynoman for $749. And they're CR29 not 26. Would they be too big? This is still going to be a street machine only, don't want to do anything that'll ruin putting around town. (but I will be doing some screaming...me and the bike...around the roads, which will be fun)

SOHC4 Cafe Racer Fan · « **Reply #647 on:** July 29, 2015, 03:36:35 PM »

I think that 29s might be too big for a street machine. 26s are available, too, through SUDCO, Cycle X and Goddfrey.

DaveBarbier · « **Reply #648 on:** July 29, 2015, 03:54:58 PM »

Seems like everyone who offers the CR carbs for the 650 recommend the 29s. Many websites say the 26s are for the smaller SOHC4s. I've read a lot on this forum, though, that 550 guys use the 26s. Strange. Still, only thing I'm really trying to accomplish is getting mechanical slide carbs to fit on the '82 650. Going to do more research and see what I come up with.

SOHC4 Cafe Racer Fan · « **Reply #649 on:** July 29, 2015, 04:56:05 PM »

Quote from: DaveBarbier on July 29, 2015, 03:54:58 PM

Seems like everyone who offers the CR carbs for the 650 recommend the 29s. Many websites say the 26s are for the smaller SOHC4s. I've read a lot on this forum, though, that 550 guys use the 26s. Strange. Still, only thing I'm really trying to accomplish is getting mechanical slide carbs to fit on the '82 650. Going to do more research and see what I come up with.

Frankly, I would go with what Mike Reick recommends based upon your application -- street use.

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Author Topic: Patina Hyena - 550/650 674cc Hybrid Cafe Build (Read 384100 times)