'86' V65 Magna build

[ToolBoxPop]

I've riden the bike around quite a bit now and I'm loving the rush this thing gives!  It feels like it's running tip top, but and low speeds and any sustained speed, the thing sounds like a popcorn machine gone bad.  I've pulled the plugs and they are all a nice light bronzed color, not too lean, not too rich from what I can tell.  I've riden slowly for about 20 minutes and pulled over to take the exhaust temps.  #1 and#4 heat up to around 460 degrees, #3 around 265 and #2 only 180.  I've tore down the highway like Peewee Gleason and stoped to take the temps and they are nearly exactly the same as slow driving.  I let it sit in the garage with the door open but no real airflow for about 15 minutes and the motor heats up to 5 bars on the guage but that #2 still only reads about 190 while the #3 is about 365 and the #1 and #4 are around 520.  The compression on all four cylinders are near identical at 185-190 psi.  What NOW could possible causing this heat difference.  Whatever is causing it is more than likely the cause of that constant exhaust/intake chuffing and popping.

[lragan]

How are you measuring the temperatures?

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With one of the temp laser gun things.  I measure them all close to the cylinder because that's all I can get a shot at on the back two.  There is about a 1/2 inch gap between the collector and the heat shroud.

[Lurkin]

Forgive me for not reading through all 10 pages  , but have you checked the spark box(es)?  I realize you've checked plugs, but maybe its a weak spark?  With exhaust temps that low, something is wrong, if you've eliminated the induction side and have good compression, time to move to the electronics.   I'm not sure what the V65 uses for spark, but would assume it has a separate spark "igniter" that you could switch/swap around.  What does the v65 use for timing/spark control?

[ToolBoxPop]

I have checked both spark boxes and both coils and both pulse generators in accordence with the Honda shop manual multiple times.  The coils ended up reading pretty high resistance so I replaced them with new dynatech coils and new NGK wires and plugs.  The spark boxes and related wires all checked out good as well as the pulse generators.  I tried swapping the spark boxes to see if the problem migrated to the other cylinders but it didn't change the outcome, so I feel like I've eliminated the spark boxes and wiring as the culprit, although the spark boxes and pulse generators are quite literally the ONLY things I have not replaced at this point lol.  I really feel like the problem is in the carburetors but I just find myself scrathing my head at what I should even be looking for when I have them apart.  I do know, that before I replaced the carbs, my bike had the California setup with all the vacuum crap and Cali carbs and that #2 cylinder was not acting the way it is now.  The problem is that I've done so much to the bike since then that it's hard to know what could have changed enough to cause this problem.

[lragan]

With one of the temp laser gun things.  I measure them all close to the cylinder because that's all I can get a shot at on the back two.  There is about a 1/2 inch gap between the collector and the heat shroud.

The "temperature gun" devices do not actually measure temperature -- they measure infrared radiation and impute temperature.  The amount of IR that comes off a hot body is very dependent on the body surface and "color". Further, the angle of reception may be wide enough that you are getting other sources included, depending on how you hold it and what it is pointed at. The inclusion of a simple laser to designate a "spot" is deceptive, since the device receives from a much wider angle than the "spot" implies.  If, for example, you are comparing a "dark" surface with a highly reflective one, like chrome, you can get the kind of variation you are seeing, even though the temperatures are the same.

Measuring high temperatures accurately is not simple.  There are a couple of options.  I use a thermocouple held tightly to the surface I am trying to measure, like under a bolt head or using a clamp such as you would use to hold together a stack of papers.  There is no easy way to switch thermocouples because the switches corrupt the results, but I have several that I can plug and unplug from the simple meter that I bought at Harbor Freight for about $20, as I recall.  It gives consistent results.   I have checked it in ice water and boiling water and it is "spot on".

Another option, using the gear you already have, is to use a spot of high temperature black paint, such as is sold for use on barbecue grills, on each point you are interested in, and get the gun close enough so that it's field of view is dominated by the spot you have applied.  If the paint bothers you on your cylinder heads or exhaust stacks, it can be removed with Methyl Ethyl Ketone (don't breathe the stuff) that you can buy at a paint store.

[ToolBoxPop]

I knew that gun wouldn't be too acurate for the true exhaust temp due to the heavy curve of such a small diameter pipe and the semi reflective surface, but since I'm using it on all four in the same manor from the same distance and angle I believe it is still a relevant reading for comparisson purposes only.  I know that I should not be able to comfortably hold on to the #2 exhaust pipe fresh off the street with my bare hands, so I know even though the readings most certainly aren't as acurate as I'd like them to be that it's at least a good indicator of a bigger problem.  thanks for the info

[ToolBoxPop]

Here's a few pics that show the missing pressed in ball in the #2 carb and then the cheap JB weld fix.

[reaperkeeper]

Pop.

Well I am shocked that this did not fix it! 
with everything you have replaced and checked  I can only think of one thing that might still be a culprit.
You checked your diaphragms right?  Not just looking at them but testing them.  Once installed in the carb use your finger or any thing to raise the slide and hold it up for about 3 to 5 seconds, then let it go.  It should NOT drop like a rock.  If it does you have a vacuum problem, either a bad diaphragm or a crack or hole some where.  You might be able to do this by just removing the air filter and the screen top of the airbox.

I am glad you are enjoying the ride!

[ToolBoxPop]

Before I installed the carbs, I was telling my wife that maybe I had a pinhole or something in those diaphragms, just as a guess.  The very same way you just described, ironically, was the only way I could think of to check for that.  They all feel spongy pushing up like it's fighting air pressure and they all just seep back down.  I did think though that #1,3,4 felt very smooth and the #2 was a little more rough feeling, so I used a greenie-weenie scrub pad to smooth out everything I could in that vacuum piston chamber and it made it far smoother.  I too really thought I had it fixed with all of this. 

I noticed something new just today.  The stock exhaust that I bought off of ebay(used of course) has been modified a bit.  There are three 3/8" holes drilled into the back of the muffler just behind the round deflector looking plate along the outside edge of the muffler.  I imagine it was to produce more noise, but I wonder if that could cause the popping effect?  Maybe the popping and the cold #2 exhaust aren't linked... but maybe they are lol.

I figure I'll throw in two more pics of the bike how it looks now.  I brushed up the aluminum valve covers and had some vynil stickers made up for the tank.

[reaperkeeper]

Pop.

ALL V65 Magnas have some deceleration popping, it is considered normal.  I know several people who have tried to eliminate it, all of them put major effort and $$ into eliminating it.  I only know of one person who was successful....for a short time.
Now if you have popping on acceleration that is a different story and not good news.

The bike looks great, it might be time to just ride!

[ToolBoxPop]

Thanks Reaper!  This thing is a blast to ride no doubt!  I'm just one of those guys that cannot take something being mechanically wrong, it will drive me completely insane until figure it out.  The only time the popping happens on acceleration is at low speeds and from a take off sometimes.  Mostly it happens at a sustained speed no matter how fast or slow.  I'll just keep an eye on things and continue to ride and have fun with it.  Maybe something will show up as an obvious fix down the road at some point!  This forum has been a fantastic help during my build up of this bike, and Reaper I appreciate you helping me out on the phone.  Thanks:)

[Jerry G Turner]

The holes are a muffler mod in order to make it a little louder and will make the popping a a little more prevelent.

[ToolBoxPop]

I went on a ride today for about 75 miles with my wife on the back(not that she makes too much a difference at 110lbs).  Before I left, I turned each pilot jet out by about 1/8 a turn to see if maybe it would change the way the bike ran and the popping sound for better or for worse.  We got out on the highway and boy was the bike running smooth.  One of my buddies has an 07 Yamaha R6 and we started goofing around on the open roads.  I got the bike up to 150 and it felt like it would just keep on climbing.  The 07 R6 with all it had could not pull away from me and I was riding two up!!  I blew my buddies mind with that kind of performance out of such an unassuming bike.  I may have fallen upon the sweet spot for the carb mix because the popping was almost gone, the carbs are still all synced perfectly and the plugs are a nice light bronzed color after the ride.  I can't wait to get my buddy back out on his R-6 when it's just me on the bike, I think I can take him!  I know at 150 his bike was really high in the rpms and I was only at about 7k or so!  I'm not usually one for high speed risks, but this bike brought it out of me today.  I really like the all out throw back acceleration, and this bike surely gives plenty of that!  I think I got her running about as good as a 25 year old bike can!  Thanks for all the help on this forum.  I'm truly lovin this v65 now!

[Jerry G Turner]

Sounds like you have it tuned in just right, now be super careful we want to keep you and your wife around.