yes,stay away from them. The pin coating wears off causing the rod end to wear prematurely.

I have noticed after 2 or 3 rods the crank pin is wore, sloppy even with a new rod,( about 6-7 gals.) If it last longer than the reg gen 5 crank it has to be better.
If the coating wears you could see when the crank pin is worn and when to change the crank.. Just my thoughts.

Hello guys, i don't know if you remember the my problems about run time. (http://www.rctech.net/forum/nitro-of...hread-726.html)

last race i went to the track on sat, and the engine was good about 9 min run time.
at sun (race day) i couldn't get more than 6 min... and my engine was cold (85ºc)

i was runing:
Byron 20%
.4 shims
6.5mm restrictors
.9mm cluth spring

today i open the engine to clean and check it up.

Piston: Should i remove a .1mm shim?
http://i26.photobucket.com/albums/c1...t/IMG_2809.jpg

Crankshaft: there's no scratches, just the yellow color was removed...
http://i26.photobucket.com/albums/c1...t/IMG_2810.jpg

Sleeve: i think it's normal
http://i26.photobucket.com/albums/c1...t/IMG_2811.jpg

Rear Bearing: was a bit hard to spin, i use WD40 and now is ok
http://i26.photobucket.com/albums/c1...t/IMG_2815.jpg

So, does anyone know what should i do to increase the run time?

su3zero
I live in Florida and there are days the weather changes and you have to re-tune for it. I use to drag race here and the density altitude ( humidity/ tempeture/ pressure ) can change here 1500ft. in 45 mins, when I ran picco's it was a tunning nightmare, re-tune every heat. Your temp shows it was running rich. I warm up my engine / car right before my heat and get on track as soon as possible and run a few laps to see if it needs re-tuned before the heat starts

We had a few motors with the black crank and they all held up very well. It is supposed to be the same Tin coating as the gold just colored black. They came in the Eb motors and also were avalible as a replacement. They are no longer avaliable and the new gold cranks are updated.

Rex

That rear bearing looks a little rusty on the cage. If it was hard to turn before you WD 40'd it I would say it is no good - replace it before you run the motor again. Also that wear on the crank is unusual, as nothing touches that part of the crank. If it were under where the bearings sit it would be explainable, but not there. I suspect your main bearing (or both bearings) are on the way out, and that is causing some movement of the crank, which is rubbing in the crankcase where you can see the scratching in your picture. This may also explain some of your run time problems.
Play it safe - replace both bearings - check your air filter is properly oiled in the dusty conditions (always run an outer pre filter) - and make sure you afterun the motor everytime it is used.
Like primo86gt stated, you may have to re-tune from day to day if the weather is real changable. One tune will not work week in and week out in changable weather.

Thnx
John

I have a 7 port with a Jp2 pipe in my rc8 truggy and I find that my low end is lacking a lot of torque and snap.
What pipe do you guys suggest that would give me more low end torque?

JP pipes are not known to be the best performers on GO engines.
The 7 Port works best with the GO EFRA 2072 pipe and header. Put one of these on and stand back, you will be very impressed with the performance.
If you can't get your hands on a 2072 then the next best pipe IMO is the Dynamite hard anodised 053. Rest assured the 7 ports have plenty of bottom end, so it is the JP pipe that is holding it back.
Also I suggest you run 1.1 springs and alloy shoes in the truggy with the 7 Port to maximize the bottom end snap.

hey grizz have u run the cobra yet ?

Yes mate - only in testing though, as our last 3 meetings have been rained off.
Done around 10 tanks of testing and set up now and the buggy is awesome.
The build was a little testing, but the end result is a very fast and stable buggy.
Wicked acceleration (and I haven't fitted the MG yet !!), plenty of steering on and off power, neutral handling and it jumps effortlessly with a lovely level flight. More than happy with it. If you don't mind putting the extra effort into the build, then I would recommend the buggy. Going on early indications it will be quicker around the track than my 808 for sure.

yeh i was looking at 2 last weekend at maitland & they where trying to dial out some steering lol very well balanced buggy.
i hope the truggy is the same, i might be tempted ! :cool:
running in the MG now in anticipation ;)

Thanks, i'll ask for a pair of bearing from Go Dealer here in Brazil.
My air filter is ok, Losi has a dual filter and i always use oil on both of them! I always check if it was well placed and lock.

Should i replace the crank too?

guys i run my go 7port yesterday..on the first tank engine is running stupid fast without flame outs,but on the 2nd tank the engine suddenly became weird when im about to start to pull the trigger engine dies every time im gonna go on a speed run,i thought it was the glowplug so i replaced it with a new one,but still doing the same thing,idle is ok it can idle until it sucks dry the fuel on the tank,richened the HSN a bit,checked again the fuel line,fuel tank for airleaks(zero air leaks),could it be the clutch spring,clutchbell bearings etc.??havent touch the engine since it became weird yesterday just waiting for others to give some advices before i touch my engine..

sounds like an air leak. around carb base,needle o-rings,back-plate. also make sure head is tight. I always seal my engines before I ever fire them up. I know that's a little extreme but when something like your describing happens just one problem that was already solved. Also sounds like the lsn is to lean.