Plug Chopping my blue Blaster

[chee_dee]

So yesterday I took the bike out,

warmed it up for about 15 minutes.
changed the spark plug with a new one.
started riding changing quick to get to 5th gear,
kept it there for about 10 seconds,
killed the engine and cruised to stop.
removed the plug and chopped it.

ps: Bike has:
FULL FMF
foam filter
no lid
Main Jet 300
pilot jet stock
Needle 2nd from top.

below are the pics. All the pics of the same plug taken around the plug (360 degrees).

Is this rich or lean?

Also, today I will be taking the bike out again and do another chop just to confirm.
I will also try and do a chop on the midrange (to check the needle position)

 

[chee_dee]

So today I took my blue bike again as well as my red bike and below are the results:

Just some info:

Temp was around 24 deg Celcius (75F)
Mix 32:1 ***edited
Sea Level***edited
Oil: Castrol Power1 Racing2T***edited
Fuel: 95 unleaded***edited

Bikes' Specs are:

RED BIKE:
MAIN JET #240
PILOT JET 32.5
NEEDLE (2ND FROM TOP)
HEADER:STOCK
SILENCER: FMF
AIRLID BOX LID ON
FILTER: OEM FOAM

BLUE BIKE:
MAIN JET #300
PILOT JET 32.5
NEEDLE (2ND FROM TOP)
HEADER:FMF GOLD SERIES
SILENCER: FMF
AIRLID BOX LID OFF
FILTER: OEM FOAM

Both Bikes were warmed up, new plugs installed. Driven open throttle to get into 5th gear and kept open throttle for around 20 seconds.

Results below:

I would think that the RED bike is close to perfect but I would think I need it a tad bit richer.
Though for now I will leave it as is because I am planning to remove the airbox lid. Then install #270 Main Jet and chop it again.

I would think the BLUE bike is a little too lean for my liking. Will get a #320 Main Jet installed and chop again.

Any advice/input will be appreciated. If not, I'll just keep this thread for my own info and for others to also join in my experience.

 

[Larry's Shee]

Unless it's 10 miles straight up a mountain, you're sea level. depending if your weather for summer or cooling for fall will determine which way to go. Ideally smoke ring should be brown. If you're coming into warmer weather, blue is slightly rich. Red is way rich. IIRC stock jet is 210/220 or 220/230 depending on year (don't recall exactly which two )
Type of oil and especially ratio will affect ring also.

 

[chee_dee]

Thank you @Larry's Shee for your input.

Unless it's 10 miles straight up a mountain

LOL got it! I am sea LEVEL.

depending if your weather for summer or cooling for fall will determine which way to go.

We are approaching Winter but I am no racer. Merely trail riding. I bought the bikes a month ago and has been building them up and restoring them. After struggeling with the PILOT tuning I am now at the stage where I need to optimise the Main Jet. Next is mid range.

Ideally smoke ring should be brown. If you're coming into warmer weather, blue is slightly rich. Red is way rich

Damn, my analysis was TOTALLY out. Atleast glad I am on the rich side of the equation.

So bottom line is, I am looking for colour and size of ring?
2mm Brown ring is perfect?

Red is way rich

That is actually good news. I am planning to remove the Airbox lid. I will do it on the next chop and see the results.

blue is slightly rich

Also good news, this is where I want to be.

Based on how the plugs look do you guys think Open Throttle in 5th for 20 seconds is enough? I will try and keep it there longer next chop. I am too scared to do it in 6th. Speeds get too high LOL.

Lastly, this is the Oil I am using, mixing 32:1
Will also update Main Post with this

.

 

[Larry's Shee]

Jetting power curves are weird. As you reach. "perfect" jetting power reaches maximum and exhaust temps are normal. As jetting goes lean power drops very little. HOWEVER , temps start to skyrocket.

It's better to leave a horse in the barn than to push all of them home.

 

[chee_dee]

@Larry's Shee , I think what u are trying to say is that I should aim on the rich side of tune?

The BLUE bike I am leaving as it is.

The RED bike 's airbox lid had drilled holes in which was covered up. I removed the covers and it now looks like this

Went out for another chop this morning and did the Mains as well as Mid throttle with the below results.

That ring looks pretty small but the brown is coming through nicely.
I think the red bike is good now. Just a touch rich .

Please advise if you agree @Larry's Shee.
Any Other comments or inputs would be great. I just want to be sure the bikes are safely tuned. I am not that much after every last drop of power

 

[chee_dee]

Anybody? I would love to get the tuning of these to done so I can focus on my next bike.

Please assist

 

[Larry's Shee]

LOL @air box. They bother with holes like that, I know you didn't do it. I have seen small vents with little filters that's probably not bad if in a lot of dust.

You can easily perform a chop without high speed. Just drag the rear brake a little bit. The object is to put as much load as possible on the engine, not overall speed.

 

[Larry's Shee]

Unless, which I doubt , you have a problem fouling plugs I'd say it's good to go.

 

[chee_dee]

You can easily perform a chop without high speed. Just drag the rear brake a little bit. The object is to put as much load as possible on the engine, not overall speed.

I got that. Thanks. I have loaded the bike in 5th for plus 20 seconds as well as in 6th plus 15 seconds.

I need a ruling on the above post though, MID and MAIN chops I did. @Awk08.. any chance of your input here please?

 

[Larry's Shee]

https://www.google.com/search?q=pro...oid-sprint-us&sourceid=chrome-mobile&ie=UTF-8

Do some investigating ​

 

[chee_dee]

https://www.google.com/search?q=pro...oid-sprint-us&sourceid=chrome-mobile&ie=UTF-8

Do some investigating ​

Buddy, I watched all those videos and googled a whole lot. How you think I came up with doing the above.

All I need now is a ruling of whether my diagnosis is right, hence the post. But I am getting none of that

 

[Larry's Shee]

My apologies. Wasn't my intention to make my answer so cryptic.
The link didn't work how I wanted. Secs call for 70* , 0-1500' above sea level, snorkel off. 50/50 mix premium/race gas 32:1. Doesn' account for any possible porting.

https://www.fmfracing.com/Jetting/Index

 

[Larry's Shee]

My apologies. My intentions weren't to be cryptic.
In first set of pics blue is slightly rich. Weird that ring isn't consistent.

Unless it's 10 miles straight up a mountain, you're sea level. depending if your weather for summer or cooling for fall will determine which way to go. Ideally smoke ring should be brown. If you're coming into warmer weather, blue is slightly rich. Red is way rich. IIRC stock jet is 210/220 or 220/230 depending on year (don't recall exactly which two )
Type of oil and especially ratio will affect ring also.

This comment was before you uncovered the air box lid.

Unless, which I doubt , you have a problem fouling plugs I'd say it's good to go.

Doesn't seem cryptic to me.

How much cooler than 75*F does it get where you're at?
Rule of thumb is one size for every 20*F of change.
Therefore, because you're going into fall/cooler weather. I think they are GOOD to go.

 

[chee_dee]

Hey @Larry's Shee, much appreciated.

My apologies. My intentions weren't to be cryptic.

I do understand

In first set of pics blue is slightly rich. Weird that ring isn't consistent.

I am focusing on BLUE at the moment and though slightly rich is where I want to be, I have ordered a new airfilter and also a 320 Main Jet. (My view before this post was it looked lean. Ouch. so the 320 was ordered before you started assisting me.)

I will none the less add the new clean airfilter as well as the 320 Main and then do a MID and MAIN chop this weekend and revert back with results.

How much cooler than 75*F does it get where you're at?
Rule of thumb is one size for every 20*F of change.

Our temp ranges 55 to 105. Now this is good info, I am in the process of getting some Main Jets in the range of 240 up to 320. Problem is, I order OEM and it takes a while. So I should be stocked soon to tune the bikes


Thanks man and please do know that your input helps me a lot. I just needed you to understand that I HAVE done research and am still doing research, watching every video I can. Problem is, there comes a point where you start asking specific questions to get better understanding of the subject at hand, that's where I am now.

This forum is very very informative. My way of giving back is documenting my learning curve as detailed as I can for future newbies to use.

Thanks again.

 

[Larry's Shee]

Here is where I first started learning
https://www.google.com/search?clien.....0....1.........0j0i22i30j33i160.F5CoWai20Pc

Also here : https://www.google.com/search?clien....0.610.1305.0j3j1j5-1......0....1.aMUTsy51O6Q

I think they're available in pdf

 

[chee_dee]

Wow!!! Good stuff. Thanks man. both saved to go through this weekend.

 

[Larry's Shee]

HAHA, You might skim through one this weekend.

Slays me though, a book I bought in the late 70's for $20 now sells for $350+

 

[bwilliamsky]

Slays me though, a book I bought in the late 70's for $20 now sells for $350+

inflation is a mofo.

 

[chee_dee]

HAHA, You might skim through one this weekend.

Slays me though, a book I bought in the late 70's for $20 now sells for $350+

Damn... you weren't kidding LOL.

Thanks again.