Hey guys, I have a question and sorry if its been asked before. Im also new to nitro stuff so bare with me :)

I recently installed a 3PT motor in my buggy, broke it in as followed. Installed a JP-2 pipe on it, byrons 30% gen 2, p3 plug. Motor runs around 210-230 with motor settings at a little lean on the bottom and a touch fat on the top. I also have the carb restrictor in that came with motor.

The problem im having is the motor seems to have no bottom end at all. I went from a 1.0 clutch spring to a 1.1 spring with no difference. I just cant seem to get any rip at all out of the bottom end. Mid range and top end are ok, just killing over bad on the bottom.

Do I have the wrong pipe on? Wrong plug? Ect? Any tips and info i can would be helpful!

Where are your needles set at?

Skeller - Im not 100% sure where they are set. I dont have the car with me here to look, so I will have to post that info later this evening.

Apart from the other good advice that was posted, I would also suggest that you check for a crack in the crankase. Look carefully where the engine mounting tabs join the crankcase. This happened to me. The crack made my engine impossible to tune.

With all the nitro rumors, concerns, facts out there...has anybody run the .25 with 20%? If not what would be the disadvantage or problems if I did? I can find 20% locally but can't find 30% and the rumors (yes I know they may be rumors but rumors that should be considered) that 30 may become difficult to find in the future are suggesting running something other than 30, and I haven't begun break in yet so a fuel change would make sense.

Just need to shim it for 20%, i would look for 25% however as it seems to be similar to 30%. You may also try a o.s p4 plug. even with 30% i found the p4 works better than the p3 everyone suggests.

i had similar issues the other week with my 3 port, it would'nt give me a bottom end unless it was around 260 F. First thing i would try though is put the top end needle at flush, then the bottom at 2 1/2 turns in from flush and use that as a starting point, the carb is very finicky so you will have to play with it a lot to see what each setting does to give you the desired results. it takes time but figure once u master the carb on the go tech you should be able to tune anything :nod:

I run 25% in everything most engines are shimmed for 25% any way.

So what's the best plug to run in my 3 port race? I have a OS p3 I'm gonna use for break in. I'm gonna use 30% Sidewinder and live in IN. I've seen in other forums that running a hot plug in hot weather with high % of nitro is a no-no.

I live in central Alabama....mid summer highs will usually be upper 90's to low 100's with high humidity........................I will only use a p3 on 30%.:nod:

If I can't get 25% what shims would I need to make it work for 20%?

Well, quite a few people shall be getting the upgraded
L.S. needles for there carbs in the mail this week. Is this
going to be The BIG FIX? I wonder what this thread has
in store for us next week? Will the GO motor tuneing be
retaught all over again? I think this thread is going to
get very interesting real soon.

Who is the quite a few people? Are the dealers getting them to give to customers they have sold? I did not hear of any of this and I just got my motors shipped out to me today.

The new shipment of engines has the revised/old style carb needles.

I think the only low speed needles being sent out are warranty ones. I am a dealer and as far as I know I am not getting any to hand out, only the ones I ordered.
Not everyone is having problems with the current carb. I experimented and ground my low speed needle shorter on a new .25 6 port and it works great. I have seen some other motors come with 2 lsn's before, just another tuning option for the conditions.

If you change needles I do think the needle settings will be quite a bit different.

Rex