Spark Plug Burn-What Ya Think

I ran the bike with 4 into 1 header at 65mph for 5 miles, hit kill switch and coasted to a stop.
Slight tan color. would not want it any whiter but not bad.

What you think?

 

That's pretty lean.

 

I thought that a light tan was good....is that too light?

So 1 step bigger on mains would be better I take it?

 

A bit to lean if not dangerously to lean

 

This is not light tan, it is not tan at all! Looks pretty chalky white to me. Definitely too lean.

How high did the engine rev at 65 mph? Your main jet may not be the only jet involved.

 

RPM at 65 not positive as I didn't look and bike new to me and not sure where it would be. About 4000 at 55 so lets say 4500 or so.

Maybe I'll switch back to stock exhaust and see what happens.

 

What a pain. I finally decided to put up with the low clearance of the 4 into 1 but now I am going to have to re jet and set up carbs which I am not wanting to do.
But then again I don't know that changing back to the stock exhaust will get the burn where it needs to be.

I want to ride. ......

 

Are the plugs brand new?

 

Yes, the first 20 miles on them.. the last 12 of which cruising at 60-65.

 

Don't get me wrong, I knew when I bought a 30 year old bike that I would have work ahead of me and now I am crying about tunning but in the last 10 days I have:

Set Valves
Cleaned Carbs
Synced Carbs
New plugs
Replaced fork seals
Installed accordion boots on forks
Installed tapered bearings in steering head
Complete cleaning of front calipers, lines fresh fluid
New old style petcock
Changed oil & filter
lubed everything
Drained and filled rear end
Installed new grips
Installed bar end mirrors
Test drive

I know I just need to get over it and figure out this carb situation or go get a newer bike. But it will be worth it in the long run.

 

Got a friend of my sons offering to pug a bung in exhaust and hook up his real time analyzer that he uses for tuning high performance race cars and bikes by measuring the data from the exhaust. Then he will compute the changes needed at all speeds/loads and drill out and reposition needles as needed. He said that if a pilot change is needed we will have to order the replacement but everything else he will do on the spot.
Then he will thread in a plug in the bung which will be available for future use after we talk about a custom stainless exhaust which he builds also or for future tuning..
After he is done everything will be perfect from what the 5 guys at my sons bachelor party that he has done it for said this weekend.

Only problem is he is 60 miles away and I will need to ride up there. I hope a 60 mile cruise up there wont be too hard on the bike running a bit lean.

I even thought about trying to find a trailer to put it on but I image that 60 miles wont be the death of the bike, what you guys think?

He isn't even charging me for the setup and the exhaust will be for cost of materials. I've already been checking out some cool stainless resonators in the $40 range. He said we could use the 4 into one header I have and change the collector to an oval design getting back some ground clearance and then go stainless out to the resonator like the one pictured..

 

i wouldn't ride 60 miles if they were that lean

 

Lets see........Pack the exhaust with steel wool!!!!!

OK start looking for a trailer I guess.

 

By the looks of your plug (dark around the thread area), you don't need to do anything with the pilot jets just yet (I see a color-tune in the future). However, you're too lean on the mains. And like you said, adjusting the needles for the correct mid-range will also have to be done.

You can do "seat of the pants" tuning, but if you have someone help with the proper set up, you can get the fuel/air ratios dialed in with a O2 sensor.
Just remember, air temp / altitude / and humidity have an effect on the tuning as well.

U-haul has great deals on trailers if you pick-up and return at the same location.

You're not alone, as I think most all of us have spent countless hours reviving these old bikes. But it'll be well worth it.

 

I will find a trailer and have a time of 10am on Friday and I will invade his shop. Really looking forward to it. I guess he mounts the screen on the handlebars and can see and record what the readings are as he rides it.

According to what everyone says and what I could find out about this way or doing things before I leave he will have me dialed in. Can't wait.

 

Nice to see he plans on getting it dialed in while on the road, and hopefully he can sync the carbs while he's at it.

 

Carbs were just synched but he said that he will redo it after getting jetting all set.

 

Aluminum Piston Crowns will melt right-through if the Burn is Critically Lean.

That Plug in the photo looks to be Critically Lean.

If you can't get the Carbs to provide some more Richness, to alleviate the possibility of a pending catastrophic failure, ... add some Marvel Mystery Oil to the Fuel.

The MMO will slow-down the Burn and let you run cooler.

 

Oh it will be corrected Friday for sure.

 

I guess I could put the stock exhaust back on and if it gets to an acceptable burn figur out s way to haul the 4into1 on the bike?????

Have any of you tried useing a colder plug to get a safe burn?

Just trying to get it to the tech so it can get lined out without trailering it.

 

The Burn isn't changed very much by a colder Plug.

The Burn intensity is determined by the Mixture.

Too Lean is damaging.
In severe cases the Oil Sheen is consumed as Fuel leading to Cylinder Wall and Piston Ring problems.

 

tried 1/2 1nd full choke runs hard to see change but notas much as I thought.

 

Half a package #3 steel wool packed against baffle from collector side of muffler.

 

Looks and sounds like the Pilot Fuel Jet and Air Screw Passages are in need of Cleaning and Flushing.

 

It's Saturday - did you ever get the bike to your buddy's house for analysis? To me the plug tends to indicate the pilot circuit is OK but you mains are too small causing it to burn hot and lean. A true WOT read on that plug is way down at the bottom of the insulator (chop off the threads) - but if the tip reads that lean then I'm sure the base will read it as well. When you put the 4-1 exhaust on how many jet sizes did you bump up or are you running stock jetting?

 

I am going tomorrow to get everything done. When I got the bike the 4-1 was already installed and the stock exhaust came with it. I don't think that the jetting has been touched and I agree with you that the pilot circuit is ok but the mains will need to come up in size quite a bit.
The ride up and back should be interesting. I'm going to run with the enrichener on full on the way up because it did help a bit with the burn. I do have to take it off when slowing to stop or she starts wanting to die when at a stop which tells me the idel circuits are close to right. She is smooth as silk at idel and cruising around town.
Coming back home should be some fun checking out the power band. I've never had her above 5800 rpm since I sm at the end of getting her all lined out. Being from a v twin background its hard for me to get the RPMs up to red line not being use to a motor That is designed to handle 9500 RPMs. When she starts to spin up something inside me starts to panic that I am going to blow things up. I WILL GET OVER THAT once I know everything is as it should be.
Dano

 

If you have to run the Bike with the Enrichment on-full, ... THAT means you definitely have a Fuel Delivery issue.

Do a Test run before you take-off for a distance run.
Lean can be bad news.

 

No I don't have to run with enrichner on at all. The bike runs great as a matter of fact but need a less lean burn no question. I am going to run with enrichner on full just to enrichen the burn a little which gave a definate light tan burn in my many combinations of tests.

 

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