BB?

[saltykillswitch]

Unless there's a new air leak somewhere it absolutely sounds like a tuning issue. Different temp, humidity and altitude.
Here's the tuning link. Print the chart from the link below it and keep it with you.
https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/

I was looking at that chart it looks like I should help alot. It would help more of I wouldn't had last plug

Burned my last plug out

 

[ThunderTiger]

I would suggest acquiring a temp gun to check running temps once you have bottomed out the tuning issue.

At least you can then keep an eye on it

 

[saltykillswitch]

I had heard that the 2.5 has alot of tune issues maybe i should bag it and put a3.3 or a picco 21 or os

 

[ThunderTiger]

2.5?

I spent time chasing the tune on the 2.5 in my revo. in the end it was a combo of HSN and LSN tuning compounded by an unseen air leak.

 

[saltykillswitch]

I have a temp gun and my Temps don't ever go over 270 to 280 that I can tell. That's why I have no ideas what is going on. I have good smoke till it starts to run like crap and not hey wot without winding up and still no smoke

 

[ThunderTiger]

you changed fuel from 30 to 33% ?

 

[saltykillswitch]

I was chasing a problem like this one before and tried to do the same and it's just pissing me off.

 

[Rolex]

Proper tuning works between both needles and the idle screw. The temp is the LAST thing you do. Tuning by temp will NOT make an engine run right at idle, takeoff and top end but is only a final safety check when everything seems to be right.

 

[saltykillswitch]

I was chasing a problem like this one before and tried to do the same and it's just pissing me off.

 

[ThunderTiger]

thats why I suggested a temp gun to keep an eye on things AFTER the tuning was bottomed out.

I know what you're saying though.. Tune by needles and get it right before checking temps.

 

[saltykillswitch]

Even brands from blue thunder to the traxxas fuel

I can get it to where I think the tuning is on point. Then it begins to lose wot and try to adjust for it and can't get it out of it

I got to get some more plugs then start over.

 

[Rolex]

When the engine is properly broken in and the tune is spot on, you almost NEVER have to change the LSN and the idle unless you move to a different altitude or change the nitro % in your fuel. However, your HSN needs CONSTANT tweaking to compensate for outside temp and humidity. It can be a daily adjustment or maybe even hourly but it will effect the overall performance of the engine.