+1. Some motors simply don't tune at all with a 5.5. There are a bunch of other ways to get a little more run time anyways.

You can always lean it out. Just make sure you have smoke and your good.

whoops . . double up

Anyone had issues installing an O'Donnell 97t in a B5 after having an OS P4 in there (i bought the B5 used with the P4 in it but don't have any of those plugs but lots of 97t's)?

its like the threads are different between the two plugs, the 97t really doesn't wasnt to screw in.

looks like I will be needing a new button :(

We've ran OS P3's (which I would assume have the same thread pitch as the P4) after running OD97T's and never had a problem. Is it possible that the previous owner of your engine possibly cross threaded the plug or damaged the first few mm of the threading in the head button?

Thanks for the response! Thread was quite possibly messed up by the previous owner. That will teach me to by a used nitro engine ;) I really just wanted a sanity check on if it was possible to change between the two brands of plugs without issue, and you have confirmed this so cheers.

I pulled the button out of the motor and very carefully (not - I just used force :) ) screwed a 97T in, it seems to cut down the thread on the 97t's like they are too large in diameter, but is OK for use, it seals OK, but I will replace the button when back in stock at Amain.

Pulling the button out, I reckon the previous owner has been blowing the filament out of plugs quite often, as there are many shards of metal melted to the top of the piston and button.

Now that I have my plug threading issue sorted, and have the engine tuned as best I can . . . . . .this things an absolute ROCKET!!!!

I must say,compared to a GO engine, , its VERY EASY to tune (listening to the engine & following the instructions on the this thread).

I'll 1000% be buying another B5 (a NEW one this time) when this one gives up the ghost.

broke in my b5 yesterday and hit the track today. im very pleased with the preformance of this motor. i would compare it to my ninja but with better run times. i was getting 10min with a jp4, power master 25% and a 97t. it was doing the surging idle thing. what is a solution to this, i put lucky 7's on the carb boot. other than that ill deffantly be buying another one when this one goes out. thanks for a killer motor at a unbeatable price.

Yes the thread pitch is different n the of compared to the OS..there will eventually be problems if you switch back and fourth

how many litres have you guys go on your B5's & 6's?

Check your pressure line, do a dunk test with tank,seal back plate and card,richen low end one hour.Only use zippy on carb boot you don't want sealent sucked in engine.

I hear people talking about 2 stage idles, 3 stage idles, fluctuating idles and etc. etc. I think that what most of you are describing are one and the same. The way that I see what's up is on the box to blip throttle at higher rpm for a sec or two, then do wot for a second or two (blows all the fuel out the case) then chop the throttle. Now this is where we start to figure out what is going on.....

a) If right after you close the throttle the engine idles high then after a few seconds the idle drops way down and the engine conks out. This is simply an indication that your HS needle is a little on the lean side (this causes the initial high idle) and that you LS needle is a little on the rich side (this is what causes the idle to drop down and/or conk out after a few seconds). So in a nutshell this is simply and indication of your needles being unbalanced.

So to fix this condition....simply richen the HS needle and hour or two (this will provide additional fuel and fix the initial lean condition (high idle) after a WOT pull. Then lean the LS needle an hour or two, this will fix the loading up on fuel and/or engine conking out that most people call the second stage of a 2 stage idle.

Hope this helps!

Ron

:nod:

lol I did what you have told many people to do and that exact thing fixed mine... so as long as you do just what Ron said your problem will be fixed...

so nice to read everything Ron says and remember it for when your struggling...

-DC-

Does anyone know of another place to order a B5, a main is out?

I also seen them in fleabay, same price as amain and free shipping. GL