[khazl]

T Was checking to see if any of the wonderful people out there could give me somewhere to go to get this straightened out, with a lot of reading I have been able to repair two 85 interstates. Both running great with main one having over 60000 miles after Honda mechanics said it would never run.

I had picked up an 86 vf700 magna, for the better half who after riding decided she wanted one of her own. Unfortunately it came in boxes, got all assembled and running halfway decent, but the problem I am having is front two cylinder exhaust stays cold, I am getting a good blue spark on both cylinders, I am getting fuel into cylinders, have been through the carbs 10times(what a nightmare), have replaced entire carb assembly twice but still no heat on front two. Causing low idle, jumping to high idle, low power, can't get over 40 mph.keep thinking no spark, no gas, no compression, front and rear both have 165 psi, no leaks in chamber. After 15 minutes running, engine temp is about 180 front exhaust still at 96. I am at a loss right now.


Thank you all in advance for any suggestions.

 

[DaveO430]

Is it possible you have the plug wires reversed so the spark is happening on the wrong stroke?

 

[khazl]

It's possible, my manual says the way they are is how they go, I don't think they are long enough to switch around, but I will try to switch them in the morning. Manual could be wrong, wouldn't be the first time.

Thank you for the suggestions
Keith

 

[khazl]

have switched wires but made it worse, did manage to get them firing don't know how but they started working after removing vacuum plugs, but now I am having an issue with idle going from 1200 to 3000 for a few seconds then its just up and down till fan kicks in then it will stall, but restart, still thinking carbs but they have been boiled, ultra sonic cleaned, soaked in carb cleaner, and air blown through all passages after each one. then they have been replaced with a known good set.

thanks for any suggestions
keith

 

[Broke Winger]

I'd start looking for vacuum leaks.

 

[Born Again]

Vacuum hose dries out but doesn't easily show the problems.
You might want to replace every rubber vacuum hose you can find. The stuff is cheap enough at any auto parts place and then you would at least have something else you knew wasn't the problem.
On a '88 it's got to be dried out.

 

[khazl]

Have went all around carbs and intakes, plenum with unlit propane torch, and starting fluid no changes in idle, just went and resynced carbs,everything where it is supposed to be just I think may be low on vacuum instead about 4 lbs lbs of vacuum, and taking out plug one cylinder causes high idle on will stall the other two no changes.

Thanks
Keith

 

[rayworx]

With the engine OFF, loosen the front spark plug wires off of, but touching, the spark plugs. Start the engine and slowly raise the plug cap off the spark plug. See if there's any increase in rpm or you can hear the engine start to run better. Then put the cap back on and repeat with the other front plug cap. If you get improved idle then the plugs could be fouled or faulty. Could it really be so easy?? Maybe…. or not.

 

[jnel57]

if it has a vacum leak the exhaust temp goes up.the only reason I can think of is the front cylinders are running rich or the intake valves are not opening far enough

 

[Wingnoob]

It came in boxes.... is cam timing correct?

 

[khazl]

the motor was assembled in a box, I think I am going to have to pull valve covers and check cam chains, it doesn't start now, all it will do is backfire through exhaust, may have jumped time, it has been starting a little hard before, but not backfiring.

thanks
keith