main jet size??

[gixxer1000]

I have my blaster apart waiting for the new top end parts to come in but I just opened the carb and saw there is a 270 main in there.I'm running no lid on the airbox and a FMF power core2 pipe.does this seem OK?? Oh yeah its freezing cold outside here in ct

 

[Herpderplol]

sounds okay for the summer. i wouldnt advise riding in "freezing cold" temps with any size jet

 

[gixxer1000]

Around here we ride on the streets when it snows out.not for too long maybe a couple hours at a time.I'm the only two stroke in the group tho

 

[Blaaster]

#270 jet could be too lean for the cold weather.

The FMF calls for a #260 alone in favourable riding conditions at sea level.

Taking off the lid will again increase the air flow and need at least 2 sizes larger main jet.

The colder the weather is the larger the main needs to be.

Jetting should be confirmed by doing a plug chop.

 

[gixxer1000]

Thank for the feedback!I'm gonna plug chop as soon as I get it all put back together.when the new top end is in how should I brake it in?I hear people talking about heating cycles! What should I do??

 

[Blaaster]

Yup heat cycles 3 - 5 of them, I like to run two tanks of fuel through at no more than 3/4 throttle but others will disagree.

You will always get many ideas on how to break in an engine, you have to choose which way you want to go.

By running no more than 3/4 throttle you never get onto the main jet circuit the bonus in that is if the main jet is too small for the modifications and conditions you will be safe to ride until the rings have bedded enough for you to do a plug chop!

 

[Larry's Shee]

start with a 310/320 for temps you have

 

[gixxer1000]

What do you mean by heat cycles tho

 

[Blaaster]

Start the engine and run it occasionally blipping the throttle until it is up to operating temperature.

Stop the engine and let it cool down fully.

Repeat this operation at least 3 times before riding.

You then need to re tension the head (20 ft lbs) and cylinder bolts. (18 ft lbs).

It is important that the engine be brought up to operating temperature before any riding is done, every time you ride!

 

[gixxer1000]

Ok great!!thanx for all the advice.thats something i usually dont do.i start it let it run for a min and ride

 

[gixxer1000]

And then plug chop to check the jetting right??

 

[Herpderplol]

And then plug chop to check the jetting right??

correct!

but, i havent been following your threads so im just going to add. make sure the engine is leak free before jetting!

 

[Blaaster]

Ok great!!thanx for all the advice.thats something i usually dont do.i start it let it run for a min and ride

I takes more than a minute to get to operating temp.

 

[gixxer1000]

Absolutley i will give it more time to warm up from now on espeacialy with the new top end

 

[Herpderplol]

just saying, i usually gave mine a couple blips of the throttle whilst warming up. after it ran for about a min.

you should notice the rpm drop as soon as you let off the throttle. if it hangs you have a problem.

 

[Larry's Shee]

when the cylinder is to where you can't still cofortably hold your hand on it, then it's warmed up.
In freezing azz temps you can actually "cold seize" by overcooling an already warmed up engine.

 

[Blaaster]

Riding in cold temperatures can be deceiving, and the cylinder temp can rapidly change.

A temperature of 32 degs can rapidly become many degree cooler because of wind chill.

http://www.nws.noaa.gov/om/winter/windchill.shtml

 

[gixxer1000]

OK guys!I got the bike back together!fresh top end.I already warmed it up twice and gonna do it again before I ride it tonight!also gonna re torque the head and cylinder base bolts.is there anything else I can do to help break it in

 

[Blaaster]

Yup heat cycles 3 - 5 of them, I like to run two tanks of fuel through at no more than 3/4 throttle but others will disagree.

You will always get many ideas on how to break in an engine, you have to choose which way you want to go.

By running no more than 3/4 throttle you never get onto the main jet circuit the bonus in that is if the main jet is too small for the modifications and conditions you will be safe to ride until the rings have bedded enough for you to do a plug chop!

/\ /\

 

[gixxer1000]

So just took the quad out and it runs strong but still knocking at low rpm.must be something In the tranny??????