Anyone running LDWingnuts single carb?

[randakk]

I just came in from the shop where I was going over this setup with an eagle eye, low and behold I found that the curb idle screw was not making contact with the fast idle cam so a slight tweak and now it idles...should have paid closer attention to detail.. the carb was new in a box so I just gave it a quick check before installation. Now if I can just figure out why the two back cylinders are running rich.....

The fast idle cam on these Solex carbs is a pretty crude arrangement. That why VW Beetle owners always had a screwdriver in the glove box...some carried hammers as well.

Getting the mixtures balanced across all 4 cylinders is often a tough challenge.on single carb conversions.

[ericheath]

They're not hammers. Hammers are for carpenters. They're up-and-down wrenches.

[cc1911]

I just came in from the shop where I was going over this setup with an eagle eye, low and behold I found that the curb idle screw was not making contact with the fast idle cam so a slight tweak and now it idles...should have paid closer attention to detail.. the carb was new in a box so I just gave it a quick check before installation. Now if I can just figure out why the two back cylinders are running rich.....

The fast idle cam on these Solex carbs is a pretty crude arrangement. That why VW Beetle owners always had a screwdriver in the glove box...some carried hammers as well.

Getting the mixtures balanced across all 4 cylinders is often a tough challenge.on single carb conversions.

i believe the mixture balance is the source of my final quirk on this bike, the intake manifold provided is soaking wet and very cool to the touch, going half a heat range hotter seems to have helped a little but I think I need to devise a way to get some heat to the manifold....ambient temp was about 90f average humidity level

[cc1911]

just wondering if I could use one of Randakks oil filter adapters with oil cooler fittings and route the hoses containing hot oil in contact with the manifold to warm it, without looking like some sort of abomination of course...hmmm

[cc1911]

Please see my thread on the ignition problem for "the rest of the story".....

[randakk]

just wondering if I could use one of Randakks oil filter adapters with oil cooler fittings and route the hoses containing hot oil in contact with the manifold to warm it, without looking like some sort of abomination of course...hmmm

That could probably be made to work, but it would be a bit of a "science project" and there are simpler coolant-based strategies. The best was designed by CC Products. Their manifold had an easy provision to use the coolant tubes on the top of the engine.

An oil-based heating strategy would be harder to shut off in warmer weather if that was necessary.

[cc1911]

just wondering if I could use one of Randakks oil filter adapters with oil cooler fittings and route the hoses containing hot oil in contact with the manifold to warm it, without looking like some sort of abomination of course...hmmm

That could probably be made to work, but it would be a bit of a "science project" and there are simpler coolant-based strategies. The best was designed by CC Products. Their manifold had an easy provision to use the coolant tubes on the top of the engine.

An oil-based heating strategy would be harder to shut off in warmer weather if that was necessary.

I'm going to play it by ear for now, the large advance in timing seems to have taken care of multiple gremlins for me..

[randakk]

just wondering if I could use one of Randakks oil filter adapters with oil cooler fittings and route the hoses containing hot oil in contact with the manifold to warm it, without looking like some sort of abomination of course...hmmm

That could probably be made to work, but it would be a bit of a "science project" and there are simpler coolant-based strategies. The best was designed by CC Products. Their manifold had an easy provision to use the coolant tubes on the top of the engine.

An oil-based heating strategy would be harder to shut off in warmer weather if that was necessary.

I'm going to play it by ear for now, the large advance in timing seems to have taken care of multiple gremlins for me..

Be aware that over-advancing the timing to get a better idle means you are "over-advanced" at full advance. Depending on the details and karma, that can be a minor nuisance (pinging under load) or cause catastrophic engine damage. It also puts lot of extra stress on your starter and starter clutch if you advance to the point of "kick-back."

You have the worst setup for a single carb conversion: '75/'77 cams and "371" advancer. You will get a much better idle with less "extra" advance by swapping in '78/'79 cams and a "431" advancer.

[cc1911]

I actually went thru my parts bins looking for a 431 but all I have are 371s so I am actively searching the net for a 431.
I have experienced no spark knock yet even during a throttle roll on riding double up a hill. No starter kick back issues yet, even tried the kickstart on a whim and it fired right up.. never would before.

I value your input and appreciate you taking time from your busy schedule to address my problem.

The cams are a good idea I may swap them into the red 75 that will receive this carb and exhaust setuo as soon as I find a suitable rack of carbs for the aqua bike and get the original exhaust repaired.

[CShroom]

I just pulled a homebrewed manifold off of mine recently. I ran a rejetted Fiat 32ADFA for a while.

Wide open performance was pretty decent, but it was way too choppy for me, and then the flooding out of corners drove me nuts. So I scrapped it for a rebuild of my chewed up stockers. They actually run better than the single conversion did. I did bump my timing up and also opened up the gap on my plugs, which helped a lot with getting the idle down to about 1100.

However, I may revisit this again using a homemade version of Randakks Webers with a set of early VW carbs or a modified Corvair Rochester.

[FirstYearDeek]

...Be aware that over-advancing the timing to get a better idle means you are "over-advanced" at full advance. Depending on the details and karma, that can be a minor nuisance (pinging under load) or cause catastrophic engine damage. It also puts lot of extra stress on your starter and starter clutch if you advance to the point of "kick-back."

You have the worst setup for a single carb conversion: '75/'77 cams and "371" advancer. You will get a much better idle with less "extra" advance by swapping in '78/'79 cams and a "431" advancer.

This is the best argument for a computer-controlled electronic ignition I've ever seen.

We always say that performance is limited by this or that, but this sounds like a major detractor to certain add-ons.

-Deek

[vagrant50]

I am still finishing up putting my 87 back together. I have been thinking about the manifold heating issue. I have thought about some sort of heating pad that could be wrapped around the manifold and pluged in to heat it. In the hot summer it could simply be unhooked and taken off. I am trying to get to the point were I can test my weber conversion.

Brent

[cc1911]

just a brief update on this conversion.

Things have worked out well for me on this, bike fires right up idles great hot or cold, milage seem acceptable though Ive never clocked it.

For my riding style the reliability and tractability outweigh any power losses that may have occured.

I can recommend this setup for anyone wanting a hassle free 'wing that will eat up the interstate all day long.

One word of advice, order Randakks intake clamps as the ones in the kit do not work.

[boiddad]

Is anyone using LDWingnut's manifold having a problem with icing besides me? While riding 15 minutes to work last week at 50 degrees, the bike was running rough and I could see frost on the outside of the manifold. I pulled the plugs when I got home and all four were fouled.

I've read where several people talked about ways to prevent icing, everything from using exhaust heat to electric heating to running oil lines around the manifold. Does anyone have photos showing what they've done?

I'm not very handy, so electric heating would probably be easiest to me. Would it work if I wound the heating element from a 12V blanket to the manifold and then covered it with exhaust wrap? Would I have to remove the wrapping for warmer weather?

I'm hoping to ride most of the winter, so I appreciate any suggestions.

[WShie]

I would think the 12 volt heating idea would tax an already marginal charging system. You might be better off using coolant.