Official Go-Tech Engines Thread

[MassiveMods]

Originally Posted by 2fst2c

Mark, I measured it on the end of the pin with the tips of the caliper because the wide part of the caliper is wider than the wear spot. It is worn the amounts shown. You can physically feel it and see it. For break in, I heated the engine to 215. Temp taken at the base of the head. Figured internal temp was around 200. Turned over nice on the box. Ran it at a good idle for 1 tank while keeping the head temp 215-220. Let it cool 30 mins. Heated the motor back up to 215 and fired it up. Leaned it enough to keep it running while doing ovals in the parking lot and keeping the head temp 200-220. Had HD tinfoil on the head. Did this for 4 more tanks cooling down 30 mins between tanks. Tank 6-12, heated as above and removed tinfoil. Leaned out each tank and widened the rpm range and kept engine 215-220 through entire tank and again cooled down between tanks. Tank 13-till broken, heated engine, began tuning on the track. Was about 90% tuned when it stopped. That was just under a gallon. The clip in the 1st piston actually broke. Part of it is still in the groove. The 2nd piston has no clip left. That is the one that had the worn pin and I also believe the pin wear caused the clip to pop. I need to get your addy because I wanted send these into you to look at anyways. Thanks

Ok .. your run in method dosent sound to blame .. hmm does the gudgeon pin have any flat spots ?

and more than happy to take a look at it for you but you should give your local distributor a look first.

let me know what you decide either way

Cheeers <<

[2fst2c]

Originally Posted by MassiveMods

Ok .. your run in method dosent sound to blame .. hmm does the gudgeon pin have any flat spots ?

and more than happy to take a look at it for you but you should give your local distributor a look first.

let me know what you decide either way

Cheeers <<

Well, I wouldn't say they are flat spots, but it is worn down. Still pretty rounded though. I've been dealing with RB who in turn has been dealing with Russell and I'm done dealing with both on this motor. I'll send the stuff to you and if nothing else, maybe it will be a "I've never seen anything like this" conversation piece for you. Thanks!

[pantera nitro]

Howdy Massive,

no issues just wasting time at work as usual!!! lol

i had some curious racers trying to work out what fuel i was running on Sunday.....

the C2 Blue Dot with no colouring is the "bomb" lol people get thrown by the lilac/mauve colour hahaha and then i let them smell it and they freak right out!

im gonna need some more for the Final Round of the Winter Cup so i'll see you soon.

Mike

[MassiveMods]

Originally Posted by pantera nitro

Howdy Massive,

no issues just wasting time at work as usual!!! lol

i had some curious racers trying to work out what fuel i was running on Sunday.....

the C2 Blue Dot with no colouring is the "bomb" lol people get thrown by the lilac/mauve colour hahaha and then i let them smell it and they freak right out!

im gonna need some more for the Final Round of the Winter Cup so i'll see you soon.

Mike

Hey Mitera !

I had a go of some on the weekend too , dang its nice ! and the smell oooh reminds me of the V8 Supercars in Adelaide !

I like the colour too man , might have to leave it liek that

And 2fast2c

ill PM you details

cheers MM

[pantera nitro]

Originally Posted by MassiveMods

Hey Mitera !

I had a go of some on the weekend too , dang its nice ! and the smell oooh reminds me of the V8 Supercars in Adelaide !

I like the colour too man , might have to leave it liek that

And 2fast2c

ill PM you details

cheers MM

yeah mate leave the Blue Dot that colour so you know your running the #1 lol

its certainly a sweet drop and the 5 port really comes into its own with it!!!

[gtxracer]

Originally Posted by bigmatt

looked a little more worn then mine. I did mine at 2 gallons. also I am using byrons gen2prodriver30%. I like it, but think my run times have gone down. even after leaning the needles. It definitely tunes easy -good power lower temps. Takes a while longer for the engine to warm up with the byrons. I am going to finish out the 2 gallons then I may go back to my sidewinder 30%. that seamed to be all around good for me. did not need to lean anything out to far,good mileage and power. was going to try torco, but have read that you need to really lean it out for good results. I may change my mind and stay with byrons. I would like to try the massive mods nitro, but god knows what it would cost to ship to me. also I see on your head that it is black. are you running a hot plug? os-p3. or to rich or is that how your fuel burns? All of my engines are a beautiful light brown. Both head and plug.

He was running the OS p3 plug. I bought some of the O Donnell 77T and 97T plugs to try out. I might just swap one in from the get-go.

Originally Posted by MassiveMods

Hey GTXRACER

Looks like the tune is rich bottom and lean top. The scrape mark on the piston can come from 2 things

1 Plug element or other head debris
2 lean high speed runs or its been flipped on its lid and over revved.

I honestly wouldn't know if he had it upside down on the throttle or not. It's not a scrape or gouge but a mark from one of the detonations. However, it may be from having a rich setting (which he said he ran it rich) and the plug element dropped in there. Either way, it wasn't anything more than a surface difference. Should I be worried?

[sickpuppy1]

Originally Posted by grizz1

Ah, ok - If you cut the needles down then they should both be pretty similar.
With the short needle go for 1.5 in on the HSN and 2 - 2.5 in on the LSN. This should get you running for sure, then fine tune from there.

Ah haa!! My engine is from the factory a short needle engine(5 port silver head) and I had posted some frustrations about keeping it running so I switched to a different motor for a while. I have been trying be religious on the .5 and 1.5 settings referred to alot around here, give or take an hour or so. But your saying the short needles are different?! Once I get the extra set of motor mount and clutch stuff I may go to these settings and give it a whirl. Interesting for sure. I really want to use the 5 port as it is going in a truggy and the motor I'm breaking in now is a 3 port. Thanks Grizz!

[spura]

Originally Posted by grizz1

With the short needle go for 1.5 in on the HSN and 2 - 2.5 in on the LSN. This should get you running for sure, then fine tune from there.

Same here, I just purchased new Caster Grenade engine(if really- 5port Goengine with some internal job from Italy...)

When I open WOT the LSN just barely come out, that means short needle?

Thanks

[Gizmatron]

Originally Posted by spura

Same here, I just purchased new Caster Grenade engine(if really- 5port Goengine with some internal job from Italy...)

When I open WOT the LSN just barely come out, that means short needle?

Thanks

I thought the short needle shold come out of the spray bar around half throttle...

[zJatoRad]

does anyone happen to have a used but in good condition 5 Port head laying around that may want to sell?

[mattwoodcraft]

the short needles come out of the spray bar and the long needles stay in the spray bar

[mattwoodcraft]

yea mate i have spare head that you can have just pay for shippuing its yours

[zJatoRad]

Hey Matt, sending you a PM..

[mattwoodcraft]

no probs

[grizz1]

Originally Posted by spura

Same here, I just purchased new Caster Grenade engine(if really- 5port Goengine with some internal job from Italy...)

When I open WOT the LSN just barely come out, that means short needle?

Thanks

There is short and short when it comes to LSN's

Like Matt said, it's all to do with if the needle comes out of the spray bar or not.

For the purpose of our discussions on here, if the needle stays in the spray bar at full throttle - it is classed as a long needle.
It requires the HSN to be set quite rich to allow enough fuel past the tip of the needle at or around WOT. If the HSN is not rich enough you will get lean bog (also when the tank level gets down).
The idea behind the long needle is a nice smooth power curve and good economy. It does require a different tuning teqhnique from the normal "shorter" needle. Nearly all your tuning is done with the LSN.
Generally HSN around flush and LSN around 2 turns in from flush will get you running, and fine tune with the LSN from there.

Again, for the purpose of our discussions on here, any needle that retracts completely out of the spray bar at or around WOT (even if it's only by a small amount) - we can class as a short needle.
Because the needle comes completely out of the spray bar at WOT you can run the HSN a lot leaner because there is no restriction to the fuel flow at higher revs.
This means you can tune with both the HSN and the LSN like most other carbs out there. The point between getting it right and getting lean bog is far wider, so tuning for people learning, or people that have trouble understanding the concepts of tuning is generally easier and more trouble free with the shorter needle.
Generally HSN around 1 - 1.5 in from flush and LSN 2 - 2.5 in from flush will get you running and fine tune from there.

Regardless of what needle you are running it is very important to set the idle gap at .7 - 1mm before you start.
The most common fault is for people to have too wide an idle gap, then tune with this fault. You end up with a motor that is way too rich on the bottom end and too lean on the top. The rich bottom end and large idle gap give a false idle, which appears to be correct unless you know what to look for.
You end up with a motor that appears to run OK, but will normally get hotter as the tank level drops, and will start lean bogging toward the end of the tank. Another tell tale sign is the revs holding up over jumps even though you have released the throttle.
This problem can be solved by setting the idle gap correctly and then setting the LSn correctly using the pinch test etc. This has all been covered in previous posts - plus I have ranted on long enough