Need some advice

[The Beekeeper]

Had the Max out yesterday and was having a great time, bike was running strong even carring the front wheel going into 2nd on a rolling burnout! running like a good Max should, went out for a couple hour cruise with a buddy and somewhere along the route somthing happened, not sure when but I found when I twisted the throttle any more than off idle or cruise position it would stumble and my power levels were way down, we made it back home fine and after work today I pulled the plugs and they looked great, porcilin was mostly white and the fire ring was a little darker than tan, electrode looked good, to me it seems the cylinders were running clean, I installed a new set of plugs anyways and cold started the bike, it fired right up and idled ok, let it warm up a couple of minutes and went for a spin, the problem is still there, I even pulled the choke up to see if it would make a difference but it did not seem to, I'm trying to figure out if this is a fuel or ignition issue, Your input would be appreciated, I could just park it for the season but I would like it to be rerady in the spring when I am...............Tom.

 

[gamorg02]

check ur idle voltage, otherwise seafoam. then see what helps.

 

[MaxMidnight]

I guess you will have checked the usual suspects like air and fuel filters and the tank breather?
Might be worthwhile to drain the float chambers to see if any cr*p comes out.
One other thing to check would be that the vacuum advance is working.

 

[The Beekeeper]

Got after it again tonight, warmed it up and had 13.3v at 1000rpm, tank vent clear, pulled the air filter out and ran it up to 3000 and hit each carb with carb cleaner to test if all the cyls were firing, I could feel each one drop out about the same, when I free reved it slow to 3-5k I could hear popping and misfiring in the pipes, I threw Seafoam in the tank and filled it up and went for a short 15mi ride, no change thus far tho it would need much more time to do it's job, I'm wondering if this could still be an electrical issue? After riding it tonight I'm pretty sure I'm losing a cyl when I get on it, I'm very familiar with automotive engines and can detect a miss easily but for some reason I find it difficult to diagnose this thing by feel, my V-65 runs very smooth and my Max has always had a little vibration to it, is this normal? I appreciate you listening to my ramblings......................Tom.

 

[VMAX1260]

did you check if spark comes to your 4 spark plugs? did this happen after you add fuel to your bike ..just a thought.

 

[The Beekeeper]

I did not check for spark at the plugs, it idles like it has at 1000rpm and the only time I notice anything amiss is when I put it under load, it seems to cruise fine as long as I don't throttle up any, I thought about the posibility of fuel contamination but I had 35+ miles on the tank before I noticed anything wrong.............................Tom.

 

[mattness]

are you sure your reg is ok?

 

[The Beekeeper]

It seems to be good, when I first started it I got a reading of 13.0v at 3000 with the choke set, after warm up I took another reading and had 13.3v at 1000rpm idle, the readings were taken at the battery posts, is this voltage high enough?

 

[VMAX1260]

you can also check the rubber diaphragm which is very easy to do. if they are old there is a possibility one or even more have a small cut somewhere so when you turn the throttle it doesnt work properly cause air is passing through.

 

[tothemax93]

This summer i had an extremely similar experience, Was running well, then out of the blue it was weak, and didn't feel right. I would have bet all the money in the world it was electrical. I check all that stuff as best I could. Then I put seafoam in, and at first no change, then a little better, then bad again. I figured if the seafoam made a bit of a difference, maybe it was in the carberators. We did the "shotgun". When I test drove it afterward, It didn't do the typical wheely from first to second. To my suprise it broke the rear tire loose.unk: Problem solved, and it's been perfect ever since.
Tim

 

[2fear]

Tom try the Seafoam for sure, put a little extra in and take it for a ride. Let it sit and let the sf work. You will want some for winter storage anyway.

 

[The Beekeeper]

Sea foam is in, rode it some more last night but no improvement, checked for spark at all 4 wires today and it appears blue and strong, have a buddy coming over a little later today and we will dive in a little more.......................

 

[The Beekeeper]

Dove into it today, comp checks good at 175psi all cyls, can't rule out carb problems but we found one of my coils cracked across the top, no arcking present but it is damaged and may be dropping out under load, will post up coil needed and get it replaced and see how it is from there..................Tom.

 

[tothemax93]

I'm not say your coils are good or bad, but the coils under my seat are cracked. they are working fine, I put silicone on them just to seal them up. I still highly recomend the "shotgun". It cost me $7.00 for a spray can of seafoam and a couple hours. I had never done it before so I took my time.
The worst case is it doesn't cure your problem, but you will have cleaned up carbs.
Tim

 

[2fear]

I'm not say your coils are good or bad, but the coils under my seat are cracked. they are working fine, I put silicone on them just to seal them up. I still highly recomend the "shotgun". It cost me $7.00 for a spray can of seafoam and a couple hours. I had never done it before so I took my time.
The worst case is it doesn't cure your problem, but you will have cleaned up carbs.
Tim

I agree, my coils on my 85 had cracks also and ran fine. I would try the shotgun also....

 

[The Beekeeper]

I did not know that cracked coils were so common on the Maxes, I will replace it anyways and do the shotgun in the spring when I get it back out................................Tom.

 

[one2dmax]

Yep, cracks are fine and only an issue when they get wet. When they dry out they work fine again.