Magna restore project

wrbari · November 07, 2012, 02:20:37 PM

Hello all, I'm currently working on a wonderful '82 magna I got over the summer, and it has a good couple of problems. I'm just curious as to how much work/what kind of work the problems will entail. I know I need a carb rebuild, which I know will take me some time. The bigger problem is that the bike will not start/stay started. It looks like a lack of compression, but I won't be able to get it towed back to where I live until the end of the month. In the general experience of people who have had problems with the engine not staying started, what ended up being the main culprit, and how major of a repair was it? I'm curious to know how much time/cost to expect to sink into the bike to get it running again. Any input is greatly appreciated!

Jerry G Turner · November 07, 2012, 04:51:02 PM

If it will start but won't keep running most probable it's the carbs are clogged up and a good cleaning will correct the problem cost your time to clean them.

Magnum Magna · November 07, 2012, 05:07:20 PM

How long did it sit?
Sound like you will probably need a good carburetor cleaning.
I know you said it will not stay running but if it runs a cheap carburetor cleaning is Seafoam.

hootmon · November 07, 2012, 05:08:10 PM

What Jerry / Robert said..

wrbari · November 07, 2012, 06:12:31 PM

The bike sat about 12 months before I started working on it. I did attempt to clean out the carbs over the summer but I am not confident I fixed them up that much since I know one float chamber is still not getting gas. I do know the other three will fill with gas, not sure if they are actually heading into the motor though.

EDIT:

I only know the carbs are still messed up because after failing to start it at the end of summer, I drained the float bowels to store it till I could tow it back to where I live. Out of the four float bowels, three had gas in them, one did not. Is that something I can glean useful information from, or should I just plan on doing a carb clean/rebuild?

TLRam1 · November 07, 2012, 08:44:05 PM

Best would be to disassemble the carbs for a good thorough cleaning and or soaking in carb cleaner. Need to determine why the one carb is not getting gas and make sure your pilot circuit is clean and functioning properly, might as well check and adjust the floats if needed.

I would rather take them off and do the cleaning right once than have to remove and do over.

wrbari · November 07, 2012, 10:22:37 PM

Will do, the cleaning is on the top of my list of things to do when it gets back here. Now I am unfortunately (in some ways) too young to have been working on vehicles when carbs were a common thing, so I hope you don't mind my asking what the pilot circuit is? I haven't heard of that before, and it sounds kind of important.

TLRam1 · November 08, 2012, 12:24:12 AM

Pilot Circuit is the low speed part of the carbs, this takes in the Pilot Jets and the associated routing through the carbs are the smallest areas on the carbs because this is what is used at idle and just off idle.

Once you get a little above idle you go into the needle jet and main jet area, the Main jets are larger and normally do not clog easily as the Pilot jets do.

Questions are fine as there are several knowledgeable people here who can offer guidance.

Where are you located?

wrbari · November 08, 2012, 09:01:01 PM

Awesome, thanks for the info! I'm in Philadelphia, PA. Now I had taken the carb off over the summer and with the exception of one jet (don't remember which one, I took them all off and put them in carb cleaner then rinsed them off before reinstalling. Since it would appear that this didn't get rid of all the dirt, what would be a recommended tool to get the dirt out? I have heard of using a small wire from a wire brush or the like, but is the a better way to do this? I don't want to enlarge the bore of the idle jet while cleaning it.

lragan · November 08, 2012, 09:33:17 PM

You are wise to forgo the wire. The brass is pretty soft, and it is almost impossible to clear the varnish without damaging the jet.

There are different types of carburetor cleaner. I still have some of the old stuff, that is very caustic, and has an oil film to prevent fumes from doing the user in. I don't think they sell it any more, but the spray types I have tried do not measure up to the dip type. I think it is made of panther piss.

Does anyone know the answer to this dilemma? Are there good dip type carb cleaners available these days?

Jerry G Turner · November 09, 2012, 05:45:46 AM

Go to jets-r-us and buy new jets they are only about 4 or 5 dollars a peice, I have used a piece of wire off of a wire brush with good results.

wrbari · November 09, 2012, 09:42:37 AM

Awesome link for the jets r us. I see they have an idle jet and a main jet, in a lot of different sizes. What is a good way to determine jet sizes? For instance do I need to use a different size based on muffler configuration?

grandpaul · November 28, 2012, 10:28:22 PM

CHECK THE SHOP MANUAL for the standard jet sizes and note that the front carbs use different bits than the back carbs.

The carbs are rather tricky to disassemble & re-assemble properly with the fiddly little throttle linkage springs wanting to go flying off into oblivion. Without them, the carbs will never work right.

Berryman's Chem-Dip works real well (metallic parts ONLY), but is gosh-awful stuff. USE IN A WELL-VENTILATED SPOT OUTSIDE, AND RINSE THJOROUGHLY. It works best if it's hot, or at least warm. Soak a good 30 - 40 minutes. Blast everything dry with compressed air.

You can easily break the fuel inlet joint pipe during re-assembly if you aren't real careful. Also, you canget them in backwards, and the hoses won't align properly.

Fun, fun, FUN!

(See "Scott's Magna Restoration" thread for some tips)