hi everybody, need some advise here i bought a 750 magna wouldnt run unless i kept choke on i changed plugs and found air filter clogged up with bird seeds its been sitting in a garage, i put new gas in it with an additive twice it runs pretty good now most times but i gotta warm it up good with choke before i can ride, at mid and top range it runs strong its at take off engine bogs i can feel its carb problem, any ides what i should do ? thanks

 

have you checked the carbs on it? and just out of curiosity what year is it?

 

as a first step, i would recommend taking the carbs off and rebuilding them. make sure you get a good Cylmer or Haynes manual (or something similar) that has diagrams if you are not familiar with the way carbs are taken apart and reassembled. but you'll want to take it apart, check for blockages and buildup (fuel from the pump isn't always as clean as we'd like to think it is), clean every part real good with carb cleaner, then reassemble it and put it back on the bike. you mentioned that the air filter was clogged up, it would be a good idea to replace it if you haven't already. i prefer to just use K&N filters because you can clean them and reuse them, and they flow better than cotton or other fabric filters.

the fact that you were having to run it with the choke still on indicates that your fuel mixture is probably too lean. at colder engine temperatures, the engine needs a richer fuel mixture to stay running, so that's exactly what the choke does. after you rebuild the carbs (definitely the first step before you try any carb tuning with jets, needles, etc), you'll want to drive it around a bit first to see if the problem has been solved. if not, pull it back in the garage and pull the spark plugs out. if you know how to read spark plugs, you can tell if the fuel mixture is too rich or too lean (if you don't know how to read spark plugs, you can probably do a yahoo or google search and find some good literature, it's not that hard to read plugs). a too-lean mixture will leave the spark plugs sort of a white color. a too-rich mixture will leave a dark black buildup. normally, the proper fuel mixture will leave a light brown tint to the plugs. here's a pretty good website about how motorcycle carbs work:

http://www.hondanighthawks.net/carb14.htm

this info may not apply specifically to your bike, but i believe most motorcycle carbs work in a similar fashion so it's a good starting point to understand what you'll need to do if you need to adjust fuel mixture. it's not really that difficult to do, it's just a matter of knowing how to do it. if you've never done it before, perhaps you can find a friend who has. but after you've done it once, you'll be able to tear the carbs down and re-jet them in no time. it's just a matter of taking the diagnostics one step at a time. make sure the air filter, plugs, and carbs are clean, and check to make sure your spark plug gap is correct, then you can start checking for fuel mixture or even ignition-related problems. you might want to have the coils and plug wires tested if there's a shop near you that does that. a weak spark can certainly cause similar problems as well.

 

Your pilot jets are clogged. I guarantee it.

 

Not sure what the hell kind of bike this is but.... idle adjustment maybe?

 

Magna is a Honda cruiser with a V-4 engine arrangement. VF 750 I believe is the model name. Pretty cool bikes actually.

 

i appreciate all the answers my magna is a 94 after i changed the air filter and plugs put new gas in it with an additive it it working pretty good but not perfect i still have a low idle problem and fails to take the gas at start outs from a light but not every time, im pretty sure im gonna have to take the carbs off at end of riding season and do them up good to make this thing perfect, i do have another question tho, when they say scynronize the carbs what does that exactly mean ? from what i read about it to me it means check vacuum on each carb one st a time and adjust so each carb is getting same amount if im wrong id like to know. thanks greg