Please help troubleshoot my poor gas mileage

[craigs449]

Ignition coils "usually" go bad at the same time. If it's running on one cylinder at idle, usually your pilot jet is clogged in one carb and not the other.

good advice, but I have even swapped carbs and the idling problem persists on mine.  It runs better with after the carb swap, but still not as good as what it should.  Gotta hook up with Baltimoregs and sync my carbs.......

[twinrat]

check your float levels ,if one is to high it will act like you are running on choke when hot (high idle) .If your impact was real high you could have upset the tang which you bend to set float hight ,they are quite delicate..Question did you do any damage to the ignition rotor or ignition pick ups .

[HPP8140]

I'm having same hanging idle issue. checked valves, carbs still hanging/low idle and poor gas mileage.

Discovered it's my ignition coil. pulled right coil & bike could idle. pulled left coil & bike dies. Right coil was not working @ idle.

What was your mileage?  Were you getting spark from both sides?  I have the same issue with mine when I do the "redneck Carb Sync"......Pull the right plug, the idle goes down.......Pull the left plug and she stalls immediately.

mileage 41k. noticed bike would also misfire randomly & bog down at low rpm or when I went off throttle the engine braking wasn't as strong. when I went to remove the coil I noticed something strange. I couldn't fit a socket on the nut. the part that holds the nut had shrunk and was close to the body of the coil. that's when I confirmed...yeah something wrong here.

No, I meant what MPG were you getting?....You said it was real bad mileage that led you to believe something was amiss.....did you check for spark at each coil before pulling them?

I usually switch to reserve between 150-160. Was only getting 130. Yeah the right coil was intermittent at idle/weak spark.

[craigs449]

I'm having same hanging idle issue. checked valves, carbs still hanging/low idle and poor gas mileage.

Discovered it's my ignition coil. pulled right coil & bike could idle. pulled left coil & bike dies. Right coil was not working @ idle.

What was your mileage?  Were you getting spark from both sides?  I have the same issue with mine when I do the "redneck Carb Sync"......Pull the right plug, the idle goes down.......Pull the left plug and she stalls immediately.

mileage 41k. noticed bike would also misfire randomly & bog down at low rpm or when I went off throttle the engine braking wasn't as strong. when I went to remove the coil I noticed something strange. I couldn't fit a socket on the nut. the part that holds the nut had shrunk and was close to the body of the coil. that's when I confirmed...yeah something wrong here.

No, I meant what MPG were you getting?....You said it was real bad mileage that led you to believe something was amiss.....did you check for spark at each coil before pulling them?

I usually switch to reserve between 150-160. Was only getting 130. Yeah the right coil was intermittent at idle/weak spark.

Got it, I have to make the reserve switch at 160-170, so I am right on par,,,,just a little throttle heavy    On another note, I have strong spark on both plugs, so the carb sync is next on the list......

[HPP8140]

pic of offending coil. notice how close top screw hole is to body compared to bottom end. shifted somehow.


image upload

[iv76erson03]

In the process of tearing apart the bike.

Choke lines seemed to be working fine. Carbs look clean as can be from what I can tell. I was trying to check the float heights but on the one carb, there is something electrical connected to it blocking the last screw. I can't get that something off without stripping the screw. Any ideas on getting these screws out? I tried the hitting it with a hammer method and that didn't work.

I'm going to put a new air filter in there because it look a bit dirty, don't know if that was the problem or not.

Wish I would have seen Kerry's guide on checking the float height before i tore the motorcycle apart 

edit: I got the one float bowl off and checked the height on it. I appeared to be between 11-12 mm, which i know is low. Could low be the problem of smelling like gas, high idle, and poor gas mileage?

[Paulcet]

Yes. However,  I found the upside-down-try-and-fail-to-measure technique to yield unsatisfactory results.

Instead, I used the u-tube method, removing the bowls while the carbs are still on the bike. You can do this, too, if you replace the JIS (looks like Philips) screws with socket-head cap screws.