Some serious 4 stroking

[Frostothebikeman]

So I just built this bike on my 5th tank or gas or so and it's 4 stroking pretty bad... only time it isn't is when it's under load like going uphill or I'm accelerating.. but once I hit cruising speed and stay there it's just non stop 4 stroking... I run 40:1 and my carbs tuned to where my spark plug looks brown but it still 4 strokes... only other things I can think it might be would be the viper exhaust I put on or the bbr stage 2 ignition... maybe I could change my jetting have jets haven't changed it yet just not sure what's gonna make it run right

 

[GreasyChris]

If your 4 stroking it's too rich. You need go to a smaller jet or lean out your needle or both. Place clip on middle notch of needle. Ride bike if 4 stroking change jet until 4 stroking stops, then fine tune needle adjustment. Start rich and work your way down.

 

[Frostothebikeman]

I did have my needle at the top notch to lean it out but I pulled the plug and it was getting a white tint so I moved it back to the middle... now I was thinking of downsizing the jet but the thing is idk if its the jet size or the fuel ratio I run it's 40:1 little rich but I'm trying to tune the carb to run 40:1.. also just an FYI the viper exhaust is a tiny bit thinner near where it mounts I've heard this may cause 4 stroking not sure

 

[Karl Snarl]

These single speeds will usually four stroke a little bit on flat ground cruising. Its just part of a two stroke. They like a load. You can play a little with the needle. A lot of 4 stroking is to rich, but a little at cruise is normal.

 

[GreasyChris]

The stock jet is usually a 70. You'll probably find 67 is about right. And yes that rope pipe robs power. Better off to gut the stock exhaust.

 

[Frostothebikeman]

I did have my needle at the top notch to lean it out but I pulled the plug and it was getting a white tint so I moved it back to the middle... now I was thinking of downsizing the jet but the thing is idk if its the jet size or the fuel ratio I run it's 40:1 little rich but I'm trying to tune the carb to run 40.. also just an FYI the viper exhaust is a tiny bit thinner near where it mounts I've heard this may cause 4 stroking not sure

These single speeds will usually four stroke a little bit on flat ground cruising. Its just part of a two stroke. They like a load. You can play a little with the needle. A lot of 4 stroking is to rich, but a little at cruise is normal.

Well I've been told it should 4 stroke flat ground occasionally... soon as Im not accelerating its 4 stroke all the way till I either hit a hill or stop gassing it

 

[Frostothebikeman]

The stock jet is usually a 70. You'll probably find 67 is about right. And yes that rope pipe robs power. Better off to gut the stock exhaust.

Any other pipes in mind? I want some type of expansion chamber even if this one robs power it sounds a lot nicer

 

[GreasyChris]

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[Frostothebikeman]

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That's the one I've been told to buy... really just didn't wanna drop money on another $60 pipe when I got one already but looks like its either that or gut the stock

 

[Karl Snarl]

That's the one I've been told to buy... really just didn't wanna drop money on another $60 pipe when I got one already but looks like its either that or gut the stock

Or make your own. I buy pipes and hack them up and weld 'em up to fit the bike.