G260 Post Port Problems - Urgent

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sperera

sperera

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Hey Guys,
As some of you know I opted to get my FG G260 ported, got it back last night, all looked good, bolted it back together and went to idle it on the bench late last night.

Soon as it fired the wheels started spinned and was revving quite high. I thought maybe my trim was off so i turned it off straight away (was only running for 2 seconds or less) checked all the caby positions, carby link is sitting on the idle screw which is quite low, all looks good, give it another pull and same thing. Let it run for maybe 3 seconds and then turned it off as I don't want to rev it hard which the engine still cold.

What could be the problem. Ive never touched the needles, how do I go about taking them back to factory settings?

When I screw the needles in how hard to I screw it?

Pls help
 
sounds more like a air issue over a fuel one.

ajust the idle screw not the fuel to start with. chances are one of the gaskets is bad and supplying more air to the cylinder, a bad headgasket will cause more air to enter the engine and also make it run faster.

drop the idle as low as low can via the screw then try to find the air leak,. if you spray wd40 or brake cleaner around the carb/head and the revs increase it will pinpoint the air leak
 
Anytime you make a change to an engine you must go back to stock settings and retune. Turn your L and H screws all the way in until they just bottom out. Now turn both screws out watching the screwdriver line until you have counted 11/2 out on both.

Follow ESP's tips here: https://www.largescaleforums.com/showthread.php?t=2761&highlight=guide

Some more info: https://www.largescaleforums.com/showthread.php?t=5380&highlight=guide

If resetting your needles does not help the idle then you need to find the air leak. It will probably be at the carb gaskets. Check that the insulator did not crack from over tightening also.
 
thanks BTB, ill have a good look at it tonight and try to get it idling right.

i will let you all know tomo how it went, I really want it right by the weekend, weather is ment to be nice and I want to see the difference in this ported job compared to stock.

thanks again.
 
ok ive managed to get the idle down but the ls needle is way out. its between 2.5 to 3 turns out. 1.5 turns and its too high then when I try to back it off there is no difference between 1.5 to 2 turns out then it starts to drop slowly.

I sprayed some wd40 around the inlet area and the rpm did drop, so i pulled off the air cleaner and holder, o-ring good. pulled off the carby, both gaskets on either side look brand new. i didnt remove the block thing behind that, its just square with a hole through the centre.

Do we still think its an air leak or should I just leave the needle out as far as it is?

I gave it a quick squirt in my back yard which is tiny and it sounds good, accelerates nice, couldnt do anything top end because of space.

I don't want to run it if there's an air leak but im not sure if there is one as all gaskets look good.
 
alright ive don't some more checks and given it a very quick run in the street. its been raining so I couldnt go over half throttle but it sounds ok. I checked the LS needle, its exactly 2 turns out, idle is quite low but thats how I like it.

what do you think I should do, run it as is and continue tuning when I have the room and traction or do more checks for an air leak?
 
If you sprayed WD on it and the Idle dropped you do have an air leak.Take the insulator block off and replace it with another,better still replace it with an alloy one from DDM's or there like.Replace all gaskets and make sure they are tight.See how you get on like that then get back to us.
J.
 
yes im running a top end pipe. DDM one.

the motor is not stalling, at 2 turns out its seems to idle fine and on bench it revs through the range no probs.

I kind of think there's no more leak but I want to be sure.
 
If its running and you have sprayed it down with no change then you should be ok. Also try spraying around the crank seals. It may just need that setting with the set up and port work you have:).
 
im going to put some silicone around the intake area to be on the safe side, should be ok, cant wait to see what its like in an open space, weekend should be nice so ill try to get some vids.
 
ok i just got back from running a tank on open dirt. when cold idle is great, when it gets warm idle drops and it stalls. also i cant start it even when warm without going 50% choke.

when i try to lean off the ls to bring the revs up the rpm dropps??? no matter how much I screw it in. What could be causing this?

I have a feeling there is still and air leak somewhere. I am thinking of taking it back to the guy that did the porting. Ive checked all the induction gaskets just not the head or crankcase ones. im running a custom head gasket as the stock let go a whole back and Rossco mate a better one for me. By the looks of it it still looks good but i haven't had the head off it.
 
At this point an air leak might be the culprit. Check your exhaust and carb bolts first, they like to shake loose sometimes. Also if you find residue around the engine head or anywhere, it's a good indicator there might be a leak in the area.




Chris
 
me and Rossco tore it down yeasterday (mainly Rossco) and found a few concerns. The head gasket was reused (porter didnt change it when he had the head off).

We changed that with a new one, then changed all the induction gaskets and made up a new exhaust gasket. Bolted it all up and it idled like a champion. Gave it a run and its no different in performance from before the port.

Having a close look at the port job im dissapointed. The exhaust is rough and not much has been taken out. He couldnt have removed allot more.

It needs a good tune, a little boggy down low so maybe its a bit lean but ill have a play with it this week and get the tune to where I want it and once its right ill take couple of vids and post it up.

But its running and I know their aint any air leaks now.

Rossco, once again mate thank you so much for your help, u saved me once again.
 
One thing I have heard about porting is that it is not always the amount or texture of the removal but the correct pitch, amount, where its removed and how it will flow. Sometimes rough is good and sometimes smooth. Thats I guess a reason to let the professionals do it. :blush: I can say I have purchased a professional race ported motor and compared it to the same unported head and could only tell a small difference but they performed totally different just the same.
Great to hear you found the issue.:)
 
thanks BTB, you may be right there. either way performance is no different from before porting. I actually think the bottom end is worse then before. top end sounds good, maybe a bit better than pre porting.

needs a good tune though, plug colour indicating its on the lean side so a bit more fuel should get the take off better.

ill keep you all posted on how it turns out.
 
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