jetting issue!

[dust1014]

Hey guys I could really use some help with jetting! Im running .080 over with uni air filter airbox lid with holes in it, full fmf gold fatty pipe, ported and polished jug, vitos carbon reeds, and im in PA around 1100ft I believe. I could really use some suggestions! My quad started pinging once I started her up and its still at stock jetting. The fuel is new and oil injector is working properly I believe, I will double check.

 

[Blaaster]

At sea level, this may help.

FMF = #260 main jet.

Aftermarket air cleaner + 1 or 2 size larger.

Air box lid off +2, maybe only one with holes drilled!

Needle in the middle slot.

32.5 pilot jet

Plug chop to confirm, as temperature, elevation and humidity come into the equation.
----------------------------------------------------

Before you make the plug chop run it is important that the float level is correct, the idle is set correctly and there are no air leaks in the system, otherwise the smoke ring may lie about the AFR.


WHEN ALL OF THE ABOVE ARE CORRECT PROCEED WITH THE FOLLOWING.


Warm up motor to operating temp.

Fit new B8ES plug, ride WOT through the gears and hold WOT in 5th or 6th gear for 10 seconds, or as long as you can safely.

Switch off the motor and pull in the clutch, apply brakes to come to a stop quickly.

Take the plug out and replace the old one for the ride home.

Carefully cut the threaded end off the plug to expose the insulator.

There should be a smoke ring of a cardboard or biscuit colour around the insulator.

If it is non existant or a very light colour, you are lean and require a larger main jet.

If it is a lot darker you are rich and may go down a size in main.

I prefer to run a little on the darker side, I may loose a little power but it is worth it for the peace of mind that I won't need a rebuild so soon.


You have to get up a reasonable speed so that you can get the motor to pull strongly.

Then hold it Wide Open Throttle (WOT) for 10 secs or as long as you can.

The idea is not to get speed but to make it pull strong at full throttle to get onto the main jet circuit.

I find I can safely do it on a short run by applying the brakes some.


If you have not enough room you can use 4th or 5th gear with good results.

 

[Awk08]

Hey guys I could really use some help with jetting! Im running .080 over with uni air filter airbox lid with holes in it, full fmf gold fatty pipe, ported and polished jug, vitos carbon reeds, and im in PA around 1100ft I believe. I could really use some suggestions! My quad started pinging once I started her up and its still at stock jetting. The fuel is new and oil injector is working properly I believe, I will double check.

i'm in pa. @ 1800'
buddys have 2 blasters with similar mods, but unported @ 32:1 mixed fuel/oil, I run 290's in them, 1 for 2 seasons now,
but i feel we could go down 1 or 2 more sizes @ this elevation, but leave them @ 290 to be safe, as these guys don't know to listen for pinging or running lean.
290 is a good, safe starting point to do plug chops:
http://www.blasterforum.com/threads/how-to-plug-chop.53237/

what compression you running and what octane fuel ?

 

[blasterkid1998]

on a unported blaster i sold a while back i was running a 280 main @ 800-1000'

 

[dust1014]

Thanks Blaaster! My engine has been pinging lately and i've been real worried about it. I will probably start with the 290 jet and ditch the airbox lid and see how that goes. As for the pinging noise is it safe to ride it for now? Or am I going to run and it have it like blow up on me or randomly shut down and die??? As for the compression I am running stock right now it has a fresh rebuild maybe 4hours of ride time on it total. I put in standard gas cuz thats all ihad at the time but I added some octane booster to the fuel only like an ounce and a half to the whole tank and also added just alil oil to run it on the fresh rebuild because I dont fully trust the injector. Ive been looking at milling my head down to increase my power so would that effect my jetting?

 

[Blaaster]

Do not run it at all without changing the jets.

Pinging is the charge pre igniting and creating an extremely hot combustion temperature, it will actually melt the piston.

It should not need octane booster!

You cannot run pre mix and oil injection at the same time without experiencing major jettin issues, it is injection or pre mix, not both.

Adding oil to fuel leans out the AFR and will cause over heating unless jetted for.

Usually milling a head does not ne re jetting for but often the fuel octane rating must be increased.

After the rebuild was a leak test performed, were any heat cycles done, were the nuts on the head and cylinder re tightened?

Have you exceeded 3/4 throttle at any time?

 

[MercMenace]

I think I would start at #300 and work down from there. If it were mine. Altitude wont come into play until 2000 ft or so.

Leaktest first if you haven't already.

Post your results. Never can have too much info.

 

[dust1014]

I figured out what my pinging was, it was my connecting rod bearing! I ended up using a 290 jet, the plug chop showed that it was right in the ball park. So I started her up to go out on a ride with fresh fuel and on my way back it just shut off on me! So I did the tear down and thats how I found that the bearing was bad. I also found that I need new crank bearings. Anybody have any suggestions on where to get the parts for the best price and if I should get a stroker kit or not?

 

[dirtysquared]

I figured out what my pinging was, it was my connecting rod bearing! I ended up using a 290 jet, the plug chop showed that it was right in the ball park. So I started her up to go out on a ride with fresh fuel and on my way back it just shut off on me! So I did the tear down and thats how I found that the bearing was bad. I also found that I need new crank bearings. Anybody have any suggestions on where to get the parts for the best price and if I should get a stroker kit or not?

The best thing to do is get your stock crank rebuilt with quailty parts! Use Koyo Main Bearings. Getting it ported to match your riding style is the best bang for your buck.

Where in PA are you?

 

[dust1014]

Im in Robinson pa, close to Pittsburgh or Washington I guess. I how much work is it to rebuild my crank? What tools and expertise will I need?

 

[dust1014]

The best thing to do is get your stock crank rebuilt with quailty parts! Use Koyo Main Bearings. Getting it ported to match your riding style is the best bang for your buck.

Where in PA are you?

Ive never heard of koyo before, the only conrod bearing I can find is a pro x which is made by wiseco, its 30bucks but it it worth it?

 

[Blaaster]

Im in Robinson pa, close to Pittsburgh or Washington I guess. I how much work is it to rebuild my crank? What tools and expertise will I need?

Unless you have a pretty well equipped workshop, it would pay to ship it to a builder.

It is a specialist job!

 

[dirtysquared]

The koyo bearings are the main bearings. Like blaaster said, rebuilding a crank is delicate work...best left to a professional


I'm near Washington PA as well, just a bit south east on 40.

 

[98blaster]

Koyo is the manufacture of the OEM bearings, you can buy a all balls main bearing kit from ebay for 45 dollars shipped, an the all balls kit comes with main seals an the OEM koyo bearings. The pro-x rod kit is the best. There is a shop in kittaning pa that rebuilds cranks an they do very good work for very cheap, pm me an ill get you there info

 

[dust1014]

Alright thanks guys, so maybe now I should mention ive really been looking around and ive got this ninja 250 motor...more like half a bike actually and I see alot of people fabricating it into a blaster. I no its alot of work but does anyone no if its worth it over rebuilding my stock motor? I have everything to do this job, I just want to know if its a good idea or not as I am power craving for my little blaster haha

 

[dust1014]

And embarrassing as it is, I cant figure out how to pm you 98blaster! Im using my fone so that probably doesnt help...

 

[dirtysquared]

Alright thanks guys, so maybe now I should mention ive really been looking around and ive got this ninja 250 motor...more like half a bike actually and I see alot of people fabricating it into a blaster. I no its alot of work but does anyone no if its worth it over rebuilding my stock motor? I have everything to do this job, I just want to know if its a good idea or not as I am power craving for my little blaster haha

If you have the time and talent, I'd say do it. That's nothing I'm capable of doing!

You could finish the one you have now, and find a roller to start an engine swap on. That way you have something to ride when your frankenstein'n a Hybrid.

 

[dust1014]

Alright, I like that idea, and 98blaster where is that shop in kittaning at???