Hi All,
I live in New Hampshire and just pulled my 1997 Magna out of storage after three years. She wouldn't start and it was obvious the carbs needed some attention so I removed and cleaned them (four times now in the past two weeks). I've done this in the past and she just sprung to life after a good cleaning but this time, I still can't get her going. I took some pictures because I don't fully understand all of the various components/fuel circuits of the carburetion system. I was hoping someone more knowledgeable could identify the orifices and other components that I should be cleaning (again).
I was able to get her to idle but only on one or two cylinders and only at full choke. Starting fluid seems to fire all four cylinders (exhaust headers warm up).
The needle valve seats and the rubber bottoms of the needle valve itself look fine although I did have a stuck open valve at first and hydro locked a cylinder. I removed the spark plugs and blew out the fuel. I changed the oil just to be careful (although when I drained it, it felt and smelled fine so it probably wasn't necessary).
I've removed the low speed and main jets from all four carbs and they were all clear but I used a couple of guitar strings and carburetor cleaner/compressed air to make sure.
The piston diaphragms seem to in good order although I haven't removed them to inspect, only manipulated the piston and observed the behavior.
I don't have a D-tool (yet) so I haven't removed the pilot screws but I'm guessing that they are fouled somehow (since that seems to be the only thing I haven't cleaned yet!). I could cut a slot in the head but I'd rather not damage the housing they fit in.
I've read of others who have created their own tool using a spent .22 cartridge or a plastic pen so I'll try to make one of those to get to the pilot screw. Otherwise it will take a week or so to get one from Motion Pro.
Forcing carburetor cleaner using the red, plastic needle into the low speed jet sprays out of the three small holes just behind the throttle plate so I'm assuming that's part of the low speed circuit and not operational at idle. All four seem clear.
Forcing cleaner into the main jet bubbles out the other side and I think all four are clear. I forgot to take a picture of the top of the air plenum but there are four pressed in fittings that seem correspond to the low, main and choke jets. One of them appears to be solid or plugged.
In the bowl, there is one pressed in jet which I'm assuming is part of the choke circuit. Both cleaner and compressed air seem to pass through it but it must be a pretty small opening based on the volume.
Forcing cleaner into the bottom orifice of what I believe to be part of the choke circuit and it sprays out of the top hole and vice versa.
The discouraging thing is that my latest attempt seems to have made it worse, not better. Even starting fluid wouldn't kick it over but I was so tired and frustrated, I probably didn't give it much of a chance before I gave up. I've been charging the battery using a 1.75 amp battery tender (a $20 Schumacher from China) so the battery is always at peak voltage and I've pulled the headlamp fuse (I've read that a weak battery can add to starting difficulties).
On a side note, MaganMan posted a link recently to ronayers.com providing access to all OEM parts (and the oil filter cross reference was awesome, too). The boots are pretty hard on my bike and I was considering replacing them with some from eBay. The OEM ones from ronayers.com are much more expensive. Are they worth it or would the K&L aftermarket boots perform as well and last as long?
I came across a long lived post by MagnAndy about rejuvenating them using an alcohol/methyl salicylate mix and people report astounding results. I wonder if it damages the structural integrity of the rubber itself.
The bike is almost 20 years old but it has been very good to me in all that time (I've owned it for all but 1 year of its life). I ride it lightly when I do ride it and I generally take good care of it (the tank was drained and the carbs run down 3 years ago before I stored it).
I'm not an expert but not a newbie, either. I just don't want to keep opening it up and doing the same unnecessary things over and over again.
Sorry for the lengthy post and thanks for any advice you can give me,
Mark
Boots
K&L's boots are actually made by another supplier. This group out of Canada carries the original supplier brand as well as a number of their rubber parts. http://www.siriusconinc.com/
I have purchased the boots from this supplier to replace those on my two Magnas. I don't have them in operation yet but they appear to be good replicas of the OEM boots. And they are made in Japan which to me says a lot more for them than being made in China. Probably only time will tell if they will last as long as the OEM boots considering the ones I'm replacing are 17 and 21 years old.
D-tool
The D-tool from Motion Pro is really handy so I recommend it. I use it with a "Skewdriver" and it allows me to adjust the idle mixture screws on the bike too. I can also use the Skewdriver to sync the carbs too. It's a great multi-use tool.
Magna praise
I haven't found a good replacement for the Magna either. Sure I wish it had fuel injection and maybe a disk brake on the rear but so far I've been real happy with it.
On to the carbs
I don't know the ins and outs of the carbs either. It sounds like you done a pretty good job of cleaning them without major disassembly or total immersion. I wonder if there are smaller passages that are just blocked. You may benefit from running them through an ultrasonic cleaner. But I don't know. If you live closer to me I'd run them through my ultrasonic cleaner for you.
Plugs?
Just out of curiosity. Do you think the plugs may be fouled after all these starting attempts with the fuel so rich from choking or starter fluid?
Empty carbs
Also if you've put the carbs on after cleaning and the float bowls are empty, I've found you have to crank the bike for quite a few seconds while holding the throttle open just to get fuel back into the carbs. Have you done that? If you can't get a little fuel out of the float bowl drains then you probably don't have the full of fuel yet.
Fuel vacuum cut off diaphragm
If you're not getting fuel in the bowls, don't forget that you have a vacuum diaphragm that controls the fuel flow to the carbs. You can bypass it temporarily or may want to make sure that you've got a little bit of vacuum applied to it. I've had to replace it at least once in both of my Magnas over the years (You can get it from ronayers.com, but you may need to look at the parts fiche from 98 and later to see it as an individual part.) I recently cleaned the carbs on my 95 and had this very problem when trying to get the bike to start. I though I had messed up the carbs somehow.
Oh. Welcome aboard!
Just occurred to me after re-reading your post. You haven't had the pilot screws out which do control your idle mixture. I am wondering if those small passages are clogged. Wouldn't that also make it hard to start?
When you take that apart be sure to note that in the base of the passage there is a tiny o-ring with a tiny washer resting on top of it. Then a spring that goes around the D-ring screw and rests on the washer. Those little buggers are are hard to find if you lose them.
Generally when I clean the carbs, I remove all those bits and separate them into four separate tupperware containers. I also remove the slide diaphragms and all the rubber components so I can immerse the carbs.
Your carbs are also getting old enough the that the fuel cross over tubes may start leaking... Some time this summer I'm going to have to separate one of my carb banks and replace all of those.
If you want a good carb kit for doing that check out http://www.v4market.com/. They also have aluminum versions of the cross over tubes which are a lot cheaper than the OEM plastics.
Hi Jesse,
Thank you for your reply and the helpful links. The boots you linked to look better than the eBay version and they're a bit less expensive too. I'm going pickup a couple of band clamps from ronayers.com, too since I've mangled two of them over the years. They still work properly but they are ugly.
The skewtool looks like a nice addition to my toolbox. I'll pick one up and the Motion Pro bit so another week before I'll be able to work on it again.
Yes, if those small idle circuit passages are fully clogged, then I'm SOL. I don't have an ultrasonic cleaner and I'd rather not break the carbs down anyway. I don't have a gauge or the know how to sync them on the bench or on the bike. I was able to find the official service manual on the web so I'm sure it's doable but probably better done by someone with more experience.
I see the pilot screw bits and pieces in the service manual and I have dental picks to extract the spring/washer/o-ring. I tend to put things back exactly where they came from, too, so the Tupperware advice is sound.
I was _really_ tempted to send the whole thing to Billy Carr but his website said that the carb service is "out of stock" so I'm assuming he's too busy right now. It *is* summer after all. I asked to be notified when it was "available" again. Until then, I can phiddle with it here.
If I do end up sending them to Billy Carr, I'll add the aluminum tubes from v4market.com and ask him to use those unless he includes them in the service. His website says that he replaces some of the hardware but I haven't looked closely enough to know if the fuel tubes are included.
As far as the plugs are concerned, I have removed them twice in the last two weeks and they will need to be replaced when this is done but I don't see anything that would prevent ignition. And the good news is that all four cylinders still fire on ether.
I checked the fuel cutoff when I first started diagnosing this. The vacuum to the cutoff is pulling vacuum but I don't have a gauge so I don't know if it's strong enough. If I put it in my mouth while turning it over, it pulses with the intake stroke. I'll find/make a u-bent tube and bypass it just to be sure. Unfortunately, those lines are two different diameters, IIRC.
I've also used my cheeks as a vacuum source to see if I can get the bowls to fill before turning it over. I thought you were supposed to crank it with the throttle closed to get the bowls to fill. Regardless, I've turned it over so much both fully closed, fully open and everywhere in between that I'm beginning to be concerned about the starter motor. I tend to only spend 30-60 seconds and then walk away for a half hour or so for fear of melting the starter motor.
I love the bike, too. It's been fun, reliable and fits my casual riding style. I had a 1985 Nighthawk 700 prior to this one (oh so many years ago) and I loved that one, too. I don't want to start a religious war but I preferred the shaft drive on that one as compared to a chain. I gave it to my brother so it's still in good hands.
I'm still hoping there's someone in here with more intimate knowledge of this carburetor who will chime in and correct my annotated images. I'm sure one of the unknown orifices is for a fuel overflow but it would be fun to know what all of them do. I guessed that the pressed in jet was for the choke but I'm not sure. Maybe there's a specific manual for this exact carburetor on the web. Or maybe someone has done a cut away of it. You never know...
Thanks again for your response,
Mark
The "Low Speed Jet" is the idle mixture screw. After removing this jet screw, you should be able to see day light by looking through the center of the idle mixture screw. It is just a tiny hole all the way down the center of the mixture screw. If you can not see day light, blow it out with carburetor cleaner until you see daylight through it. There are holes on the side of the mixture screw, those will get cleaned as you blow out the center hole. Good luck.
If you continue using starting fluid you'll be committed to replacing the diaphrams despite the current condition. Lay off that stuff unless you want to throw money away.
The bike will fire on 2 cylinders.
Does it fire on all four on full choke. If not either you do not have spark at those 2 plugs or there is no fuel getting to the cylinder assuming a motor mouse hasn't take up residence in your air filter.
Faced with your problem I would do the following:
1. make sure the battery is good. Take a fully charge battery and get it tested. Yeah, I know it's good but do it anyway so it's off the list. Or jump it off your car battery WITHOUT the car running.
2. Check for spark at the 2 cylinders that aren't firing as in using a spark tester.
3. There is a filter screen associated with the petcock. Inspect it and replace if necessary.
4. Check for leaks around the boots with an unlit propane torch. If it is sucking the propane in the cylinders will fire, rpms will pick up. Safer and less damaging than ether.
4. Check for gas in the carb bowls. If there is no gas present then you have a bad float, float seat. float needle or the float is not adjusted correctly or an obstruction upstream fro the carbs. See #3.
You need spark, fuel and oxygen for combustion. Is there spark at the plugs? If yes is gas flowing to the carbs? If yes is gas filling the bowls? If yes and spark is at the plug your carbs are still dirty or really really out of adjustment.
Billy will clean your carbs and send them back to you bench synched but wiithout a vacuum synch on the bike running performance will have a lot to be desired.
Like Andy says, a carb aint clean until it is clean where you can't see it. If you're not going to purchase an inexpensive/used ultrasound cleaner if you want to try it yourself again you'll need to soak the carb bodies in carb cleaner for a couple days and start again. There is no shortcuts to cleaning carbs.
Also here's a more detailed write up on carbs that may provide more clarification on the Magna's carbs since they're from the same era.
http://faq.ninja250.org/wiki/How_a_carburetor_works:_Carbs_explained
Wow, MagnaMan, that's a great write up! Especially the "Carburetor photos" and "carb cleaning article" links. Like I mentioned to you before, the only thing I haven't done yet is to remove the pilot screws so I probably have only cleaned half of the pilot circuit.
Once the D-tool bit and new boots arrive, I'll be ready to tackle it for the final time. If I haven't damaged anything by using starting fluid (per LateStart's post), maybe it'll work this time.
If after this last valiant attempt I still cannot get her going, then I'll have to wait until Billy Carr gets back from his vacation and get slotted into his and Dana's busy schedule.
Thanks very much MagnaMan for the links and you too, LateStart.
Mark
Leave your pilot screws turned out about 2.5 turns once you clean those.
Hi Guys,
Well, I guess the fourth time is the charm. I pulled the carburetors and inspected/cleaned them again (I still don't have the D-tool bit or the boots). I put her back together and she fired right up.
I had some smoke from the exhaust and discovered that I had overfilled the crankcase so I changed the oil again and added only the 3.1 quarts in the official service manual. The smoke problem cleared up but it fouled the plugs so I had to wirebrush and used a little carburetor cleaner on them and they look fine now. I'll replace them after I run a few tanks of clean fuel through. I put about 50 miles on her so far (I didn't want to get stuck too far from home).
I guess that I'm lucky that the ether didn't destroy anything. I've used it frequently in the past but based on LateStart's advice, I'll not use it anymore.
The idle, low speed and high speed circuits are all active and responding well enough. I'll probably re-jet these in the Fall. The Dynojet kit looks promising. I forgot to mention that this is a California bike. I brought it back with me from San Diego. I've put very few miles on it here in New Hampshire. I'm going to have to read up on what I have to do to remove the CA emissions control bits and pieces. I could just leave things as is but as an engineer, it's against my nature. Besides, the stuff probably doesn't actually work anymore.
I'd still love to hear from anyone who can identify the ports/pieces in the attached images. The overflow ports (I'm surprised there seem to be two overflow ports) or perhaps the correct choke (enrichment) ports. Carburetors are complex but an amazing engineering achievement.
Thank you very much for your helpful links and encouragement,
Mark
Glad to hear it. You're a pro at carb removal now. ;-)
I've heard mixed reviews of the DynaJet kit. Some people say it's runs like crap. Others swear by it. Greg Cothern used it and I think he had good results, but he also had the SuperTrap pipes with different baffles that allow you to adjust the back pressure. The Dyna kit involves drilling the slides so it's permanent.
As far as removing the California emissions, I think most of it just has to do with making sure the vapors are either burned off or filtered right? It sounds simple to remove but Dave Dodge once told me that every bike he'd ever worked on with missing CA emissions was much more difficult to tune. So after your recent carb adventures you may want to just adopt the "It ain't broke." philosophy. ;-)
So are you going to make it out to MootMag in August then?