tweety Posted May 11, 2004 Share Posted May 11, 2004 So my friend has an 83 Honda Magna that he commutes on, and recently he's started to have this problem. It sounds really familiar to me- I keep thinking this happened on my old 85 Honda Rebel once but I can't quite remember what the problem was... When the bike is cold it starts & runs fine. then after it starts to warm up a bit the engine kinda bogs down when adding gas. He says if he tries to rev it up a bit then it doesn't react too well, sounds as if it's thinking about dying. Otherwise he's been able to ride it still, just taking things slow & easy. Surprisingly, a few local dealers & shops said they don't work on bikes this old... :roll: We're thinking about taking a look at the plugs & carbs but thought I'd test you guys if these symtoms sound familiar at all... Thanks in advance for any ideas! Quote Link to comment Share on other sites More sharing options...
flyv65 Posted May 11, 2004 Share Posted May 11, 2004 A bit more information, please. Is it the V65 or the 750/700 Magna (or the 500?). Has he been riding the bike regularly, or was it sitting for a month or so? In all honesty, this "sounds" more like a fuel/jetting problem than anything else...which makes me think that he's got some partially occluded jets in the carbs, but other things can contribute to the problem (although it's not often the plugs). Start by checking the air filter and making sure nothing crawled in there to nest for the winter. If he's got a spare fuel filter, put it on (oh, lighten up-they're like $3). Then trot down to the local Pep Boys or Checker and get a small bottle of Chevron Techron fuel system cleaner, the expensive stuff (about $8, treats up to 12 gallons, yada, yada, yada). Dump the whole thing in, fill it up, and go ride the tank out. This is the cheapest, easiest way to start. If after the tankful of gas has run through and it's still not running right, I'd pull the carbs and do a partial teardown and cleaning. Cliff Koch on the Sabmag list has an excellent write-up on the procedure posted somewhere (probably the FAQ, now that I think about it), and the hardest part is putting the damn things back in, to tell the truth. Ping me direct if your buddy wants more info...but what I've jotted down is the *basic* approach we take/took to this problem on the list. I know, I know, bottled system cleaners don't work-but the Techron does. I've seen it too many times to discount it. Bryan...does me good to know the Magnas are still out there, *sniff*.... Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted May 12, 2004 Share Posted May 12, 2004 I had a V65 Sabre, totally agree with flyv65. The Chevron Techron IS some good stuff. Although I would split the bottle between 2 tankfulls. With a bike this old the vac. diaphrams in the carbs may have dry rotted and ripped causing no movement of the slide. Even in 1 carb this would ruin carburation. Pulling the carbs on this bike is a pain unfortunately. Quote Link to comment Share on other sites More sharing options...
Northman Posted May 12, 2004 Share Posted May 12, 2004 Yeah, check the airbox for nests, etc., and check the choke for proper operation. It sounds to me like the choke is partially stuck on, or it's just plain rich for some reason. Quote Link to comment Share on other sites More sharing options...
jimmyknot Posted May 12, 2004 Share Posted May 12, 2004 I did end up changing the plugs and they kinda needed it, checked the air filter which was a bit dirty but not bad, and added the fuel system cleaner which seems to be doing the job sofar. I have only ridden it a bit but there is already a huge difference. Hopefully by the time I finish the tank everything should be back to normal. Thanks again for the great advise. Quote Link to comment Share on other sites More sharing options...
tweety Posted May 12, 2004 Author Share Posted May 12, 2004 Welcome aboard Jimmyknot. This is the guy with the Magna troubles. You realize of course now that you're on this forum you need to go buy yourself a Honda Blackbird... :wink: Quote Link to comment Share on other sites More sharing options...
flyv65 Posted May 12, 2004 Share Posted May 12, 2004 Glad to hear that the bike is straightening out for you, Jimmyknot. If you've got any other problems with her, lemmee know or sign up on the Sabmag board. And as for Tweety...cut him some slack. The progression from V45 to V65 to XX is well documented and not to be trifled with. Best just let Nature take its course :grin: . Bryan...naturalized... Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted May 13, 2004 Share Posted May 13, 2004 "And as for Tweety...cut him some slack. The progression from V45 to V65 to XX is well documented and not to be trifled with. Best just let Nature take its course." That's a fact! I just skiped the V45's. :wink: Quote Link to comment Share on other sites More sharing options...
jimmyknot Posted May 13, 2004 Share Posted May 13, 2004 Question: So far my bike has been better but it still doesn't have the same acceleration and higher speed (80+) that it usually does. I am only halfway through the tank so far but will I see more improvement or have I kinda reached the limit for what I have done? I will probably have to get the carbs cleaned out huh? Thanks again. Scott v45 magna rider Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted May 14, 2004 Share Posted May 14, 2004 I would run it a little more but with what you described is classic for a stuck slide in 1 or more carbs. :cry: Doesn't that model also have a fuel pump? It's got a lower sub tank? I would check the whole fuel system out. It's not getting enough gas. Quote Link to comment Share on other sites More sharing options...
Ronnie Posted May 14, 2004 Share Posted May 14, 2004 I do miss the V65 Magna......still say the XX would have to come from behind to catch the V65 up to around 80-90mph, then of course the XX would pull away. As far as the trouble he's having, possible one of the coils is acting up. or spark boxes? Good Luck Here is a great place for most answers for V65 troubles http://www.v4hondabbs.com/index.php Quote Link to comment Share on other sites More sharing options...
flyv65 Posted May 16, 2004 Share Posted May 16, 2004 Question: Â So far my bike has been better but it still doesn't have the same acceleration and higher speed (80+) that it usually does. Â I am only halfway through the tank so far but will I see more improvement or have I kinda reached the limit for what I have done?I will probably have to get the carbs cleaned out huh? Possibly- did you double up on the dosage of the Techron? It might still get better. The Tachron *slowly* dissolves the varnish that forms in the bowls and floats up to the jets. If you did, it might be time for a "real tune up (you know, plugs, valves, and a carb balance. It's not difficult, and frequently, valves in the old V4s lost a good amount of power if they were out of spec. Bryan...but run the Techron first... Quote Link to comment Share on other sites More sharing options...
jimmyknot Posted May 26, 2004 Share Posted May 26, 2004 Well after inspection of the bike we found out that one of the igniters was bad. I did get the carbs cleaned out and that needed to be done as well. It had some strange cotton-ish deposits inside of it? But for the main problem of the top end power not being there it took a new ignitor which was a bit pricey. It runs great now though. Sounds really good again. Quote Link to comment Share on other sites More sharing options...
flyv65 Posted May 27, 2004 Share Posted May 27, 2004 Are you talking about the spark boxes that are mounted on the rear fender under the saddle? If you are, did they give you back the part? sometimes you can pry them apart and carefully re-solder the connections that have loosened over the last 20 years...then you've got a spare. Bryan...you really need to get on the SoCal maggots mailing list... Quote Link to comment Share on other sites More sharing options...
Pete in PA Posted May 28, 2004 Share Posted May 28, 2004 That reminds me, I did the same thing when I had a V65 Sabre. Once you've diagnosed a part as bad, try to fix it. It's broke already. I pryed the box apart and saw a resistor that was obviously fried. 39 cents at Radio Shack, a little soldering, and I just saved $300.00 :shock: It's still going strong for the guy I sold it to. :grin: Quote Link to comment Share on other sites More sharing options...
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