Set the idle gap with the restrictor out so you can see what your doing - then re-fit it before starting the engine.

From what your saying, and the fact that it won't idle at all with both needles flush - it sounds like your idle gap is too small.
With the idle gap too small and the LSN rich (as it will be when flush) the air/fuel ratio will be way too rich.

With a slightly wider than normal air idle gap set for run-in, and both needles flush, the motor should idle albeit slowly, as it will still be rich on those needle settings.
Even with a .5mm gap and both needles flush the engine will still idle (but only just).

On a new motor with a new front bearing, funky idle conditions are going to be the result of an inbalance in the idle gap width / LSN relationship 95% of the time, providing everything external to the carb (fuel tank, exhaust gaskets, fuel line etc) is in good condition.

I'd work on setting the idle gap wide enough so the engine will idle slowly with both nedles set at flush, then continue the run-in procedure as per Ron's instructions.

Once the engine is run-in you can re-visit the idle gap setting (set to .5mm) and tune for a good idle and peak WOT performance from there.

I'm not really chasing a temperature so but just wanted to stay at or under 200 for the next 6-8 tanks. I ran another tank through it after going back to flush and flush and even with a pretty slow idle it's running in the 230 range. It just concerns me because it shouldn't be that high. Ran out of light before I could try another tank to see how rich I could go and still idle. Once the kids go to sleep I'm going to pull the plug out and check it out and try to get a better measurement on the idle gap.

If it's running in the 230 range with the HS and LS both set to flush then there is something going on with fuel supply which is causing the engine to run lean because that's way too hot. So now you have to go into problem solve mode:

1) Check the carb and make sure it's fully seated,

if it is to do a quick check to see if it's your fuel supply system (tank, lines etc.) by...

2) Pulling the carb from your B5 and install it on the B6 (it's just the pinch bolt that needs to be loosend so it's a quick swap) and test the engine to see if you see the same thing happening.

If so you know you need to....

A) Look over your fuel lines, tank, clunk etc. to see if there is some type of leak and/or blockage.

if the engine runs fine after doing 2 then you know the issue lies with the other carb in which case....

B) You probably have something blocking the carb internally, pull the needles and spray out the passage with carb cleaner. Put a small drop of after run oil on the o-rings of the needles and re-install and then install and test again.

Bit of dirt or O Ring material in the high speed needle jet perhaps.
That can cause a multitude of crazy tuning or mis-tuning scenarios.
Give it a good flush with the needles out as Ron suggests.

Ok, so all I've figured out is the carb is ok, put it on the b6 and ran fine. Now the fun part.

OK carb checked, the motor is new so more than likely that is not the issue either (I'm thinking it's a fuel supply system issue) but to double check as it sounds like you have a second vehicle (that the B6 is in now), you can swap the B5 into it and run it quickly. That way you can quickly confirm that the issue does not lay with the engine.

Is the b5 the go to truggy engine as a general rule? I have the b6 in my buggy and have a new b2 but i was thinking about a b5 for truggy

Worked on this with him at the track today. Carb swapped from B5 to B6. Ran fine on the B6. Upon further inspection, found a cut on the fuel line inside the tank just after the clunk. Tank holds pressure and a vacuum, line on outside of tank to carb and pressure line is good as well along with a good seal at the top. Waiting to hear if the fuel line on the inside fixed it:D

For the most part, the B5 is a truck motor and the B6 is a buggy. But you could run either motor in either car and still have more than plenty. Just depends on where you need the power band to be. B5 down low to mid, B6 mid to top.

The B2 is a great truck motor. A touch more bottom than the b6 but not as much as the B5 I think. Smooth, powerful and solid mid range. Only thing I noticed was the lack of RPM's. Can mostly be resolved by adding a tooth to the clutch bell. Other than that, it would make a great truck mill.

Appreciate you helping work through the issue. It never ceases to amaze me how many little things can potentially affect the performance of an engine. Both of you please keep me in the loop on how things progress

i'm going to run it today with the shortened vent line and the clamped fuel lines and just stop before it gets down to the split in the clunk line since i don't have anything to reach that far into the tank to remove and replace the tube and i seriously doubt the local hobbytown has a hose that big. one thing i thought about trying while waiting for the new tank is to completely gut the tank and run a straight hose through the tank with a standard size clunk instead of the nipple and separate inside hose since that inside hose is so stiff that it hovers above the bottom of the tank anyway. thanks for all the help guys, can't wait to get this thing out on the track.

So I think we're going in the right direction. Ran the tank down tonight and seemed to be pretty even until it got down to the split in the internal line. Got a new tank on the way so I'm gonna pull this one out and see if I can mod it.

Glad that it looks like you guys got everything worked out. Just was flipping back through the last few pages and ran across your post below, it's human nature to assume that anytime an engine does not operate properly that there is something wrong with the engine, but I think that this is a shining example of how every little detail about a build plays a factor and that often when people assume that an engine is "crap" so to speak the issue does not even lay with the engine, it's something completely different! In this case.....


.....it turned out to be probably less that $0.10 cents of fuel line inside the tank that caused all of these issues lol!

Very true Ron, it's even more frustrating and confusing when everything is brand new out the box. New engine, pipe and truck kit, had no reason to think anything would be bad. And honestly I think the split line was faced down at first, I tried to remove the nipple and clunk line but it wouldn't fit out the tank without separating so when I screwed it back in it just ended facing up. Blind luck, good advice from everyone and a good eye by jerm.

Wish I did this when I got back from the race yesterday, went so much faster than expected. The clunk line was garbage, the rip had grown from yesterday and completely ripped off while removing it. fortunately it was a standard id hose just big od which made it too stiff to really be a useful clunk but it allowed me to reuse the stock clunk. Hopefully the weather will play nice tomorrow and can test it out.

Ok so I tried the modded tank and new stock tank and still does it. Huge difference between full tank and low tank, and also put it in the buggy and was a little cooler but still big change in tune from full to empty. Changed the full lines again too.