Topic: Patina Hyena - 550/650 674cc Hybrid Cafe Build

[DaveBarbier]

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

[DaveBarbier]

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.

[calj737]

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).

[DaveBarbier]

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]

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]

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.

[calj737]

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 

[DaveBarbier]

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]

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]

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.

[calj737]

Bingo!

[DaveBarbier]

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

[DaveBarbier]

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.

[calj737]

CR-26s would be a great match. I be,I eve I've read that 650s with pods are an absolute tuning nightmare, but I may be wrong on that as I have zero experience with those carbs. Besides most will say pods on any bike are a tuning nightmare 

If Haris doesn't have an answer, perhaps a friendly email into Mike Rieck. He no doubt has great insight into fueling a head properly.

[DaveBarbier]

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]

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

[DaveBarbier]

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]

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.

[DaveBarbier]

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.

Yeah I'll definitely get his opinion and most likely just go with what he thinks. Would be really nice to get a rack of CRs, but I'm going to exhaust cheaper options first. Would love to just get some 750 carbs and have a plate machined for the right spacing and that be that. But I'll have to deal with slide linkages and fuel and air hoses and choke stuff...should be fun.

[DaveBarbier]

Side note, got my new pair of TEC condensers off eBay. Saturday can't come quick enough.

[P.abrera]

Have recently seen a 4-into-1 carb set up at a buddy's shop. Manifold from from head into one big carb. Duno how it performs but it was interesting.


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[DaveBarbier]

Have recently seen a 4-into-1 carb set up at a buddy's shop. Manifold from from head into one big carb. Duno how it performs but it was interesting.


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I was thinking about this a while ago when my 550 carbs were giving me sh*t during the summer. It definitely simplifies things, but why would Honda do 4 individual carbs? I like the look of 4 carbs anyway, and don't plan to go changing things around that much, but it is definitely interesting!

[calj737]

Possibly a Weber, Paolo? There's some of those floating around, mostly heard about them on 750s. You could also try Murrays 2:4 rig with a pair of Mikunis. I don't know if he makes them for a 650 though. Devin runs a set on his 750 and really like them.

I bet you Mike or Bodi or Andrew (TrueBlue) know of a carb swap or manifold swap to fit other carb types. This carb and exhaust issue is about the only thing dissuading me from a 650 engine bump, personally.

[DaveBarbier]

I bet you Mike or Bodi or Andrew (TrueBlue) know of a carb swap or manifold swap to fit other carb types. This carb and exhaust issue is about the only thing dissuading me from a 650 engine bump, personally.

Got a couple emails going, we'll see what happens. Haven't even started looking into exhaust yet.

The manifold is integrated on this 650 so can't swap just that. If that was an option I bet that would make it easier to fit more carbs.

[SOHC4 Cafe Racer Fan]

Unfortunately I already have the later '82 top end and rebuilt stock 650 carbs from Harisuluv. Otherwise, I might consider sourcing a 79-80 head, which matches the 750 spacing and allows you to easily use 750 slide carbs or CRs spaced for a 750.

Let me know what size CRs Mike recommends.