I used to run 80 - 125K in the rear diff and 500k - 1M in the front diff which I'll be continuing with onto the SRX8-GT initially.

Hey Dan. Have you seen the "default" oils for diffs in the SRX8GT? They are prity thin in comparison. Are you going to try them out first or jump straight into your thicker set up?

Regards
BM

i talked to the guys at the FL serpent track. they use 1.5mil in the front and 80k in the rear, for the srx8gt all dy

Also because the diff gears are a much finer pitch than the 3.1 gears you need to use much thicker oil right off the bat. I've built my SRX8-GT kit with 125K rear and 1M front at the moment. I will also build up a pair of spare diffs with 250K and 2M as well to try a big change to see what it does on the new car when I finally get the chance to run it! I will also try a softer rear diff but I never liked going too soft in the rear on the 3.1 so we shall see.

Thats interesting Dan.
That Serpent have decided to go to a smaller diff' with closer pitch when other makes have gone the opposite direction and opted for a larger diff' volume, larger pitch and teeth?!
The compensaters in the new Serpent diff also intrigue me too along with 3/4 filled diff' recommendation. Very interesting for sure. I look forward to trying this car out!

Regards
BM

The diffs are much smoother than the old diffs and using thicker oil for the same feeling as the old diffs should make them more consistent when hot. Personally I run the diffs without the compensators fitted as we do with the SRX8 buggy.

Hey guys, can anyone tell me the ID of the clutch bell used on these? I'm trying to find more gear options in my kyosho gt car. Tia.

Bell = 600586

600497 is the newer version of the steering hub (still 0 degree) gives you option to use smaller or the full size bearing. Performance difference is still the same....and of course, I would prefer to use the newer one, which is what you are using now.

Yea, looking at that and the lightweight version. Trying to find ID, and OD on pinion areas. Also if mod 1 gears are made by serpent in larger sizes. Can you help?

Thanks

I am only saying they are both 0 degrees (caster angle).........offset or not, I would prefer to use the narrower front track width with the thinner hex adapter. The narrower front end the better (more steering traction).

Serpent Cobra GT RTR Trans not Shifting One other reason why.
 

Just got a Serpent cobra gt nitro 2019. First off I bought from Serpent not a hobby outlet. The car came with slicks and not the treaded wheels, it also came with a non digital lcd screen radio as advertised.
The wheels, I called and he said he would ship out the correct set "See if that happens".

He stated everyone wants the racing slicks so he changed the cars to come with the slicks instead. The radio, I didn't care about because who really uses the rtr stock radio's. LOL Than he stated he had 40 years exp in these cars. Thats funny because my first run with the brand new car, the trans never shifted and below is why.

If he has 40 years exp than why would he use screw on gears to the clutch causing the trans to not shift? I know the guy is great at what he does and he does have awesome kits and RTR's but why have screw on gears?

Here is another reason why the trans might not switch gears.

The large gear that screws closest to the clutch un-screws and gets forced against the smaller gear, locking them together in essence locking up the trans so it wont shift.

Me with 35 years exp in all facets of nitro hobby ain't going to call this guy over it, because with 40 years exp he would have known to use a grub screw or at least a spacer to keep the gear from vibrating loose into the other gear.. I'll fix it myself.

I love this car. Unfortunately I will be selling mine.

The Serpent Coba GT rtr is a SH*T truck of a mess. I just bought the 2nd to last in stock from Serpent. I being in the Nitro world as a IMPBA Nitro Boat racer and starting in R/C car world in the 80's have a lot of knowledge in R/C. Meaning I am not some weekend warrior.
The car came without the treaded tires as advertised. The car did not come with the LCD Radio as described. The car did not come RTR as described.
I as many do check the car over making sure visible screws and such are tight, they were. The problem was the internal grub screws and trans, and drive gears were all loose.

1) I fuel the car up and start the engine for the first time, well I attempt to start the engine with the factory setting. No go way to freaking rich. The carb works best at 2 1/4th turn out on the HSN, and 2 1/2 to 3 turns out on the LSN, strange as most if not all .21 Novarossi's I have owned over the years require 3 1/2 HSN, and flush LSN.
Ok so I get the engine running and take off, at about when the trans was to shift it didn't, so I bring the car in and look it over and the 2nd gear drive gear that is screwed to the clutch housing was loose and walked off the threads and locked into the 1st gear that's screwed on, you think they would have placed a teflon spacer in-between the two gears to keep this from happening. I guess 40 years exp don't mean anything in a design perspective.

2) I get that fixed noticing the 2nd gear drive gear on the clutch housing, when it walked off into the 1st gear, it also mushed the 1st, and 2nd plastic trans gears so I had to file those down to get the mesh correct. All gears are fixed and smooth again, and run the car again, again the trans did not shift so I took the transmission out and the setting screws were so tight the shoes could not spread apart/expand they were not at the 3 turns or so they were all the way tight and the two grub screws that bring the shoes close to the drum were missing so the shoes have a slightly long travel/expansion to engage the drum.I turn out the set screws to 6 1/h turns and the trans started to shift. Albeit without tension as the springs at that point had nothing to seat against. when I placed two grub screws where they go on the shoes and adjusted the shoes to a tighter gap in-between the shoes and drum and tightened the set screws is when I got 3 turns or so that the manual states with some tension on the springs to retract the shoes and downshift to 1st at lower RPM.

3) Before I could install the grub screws on the transmission shoes I ran the car again, and have no fear the trans shifted but the engine screamed because the yokes that exit the differentials were slipping on the pinions both front and rear. I take the car home and disassemble both differentials and the grub screws that attach the yokes to the pinions were so loose and did not even have any form of lock tight on them. So I fix that.

4) After thinking it was strange for the Novarossi carb be set so lean even without the orange restrictor I contacted novarossi about, asking it that was normal. They told me they don't know the specs of that engine or carb settings. I mean WTF What? They manufacture an engine but know nothing about it, what the he double L is that. They did not even want to talk about it. I am wondering if it truly is a Novarossi manufactured engine. Remind you I have a bunch of Novarossi engines and even Sig Rossi engines, thats how long of a history with the Rossi name I have. My first true Novarossi was a .21 blue head "C" Competition engine and many marine engines of all port counts. So I guess the Novarossi engine is some magicly different engine that no one knows anything about, it more or less just poofed into existence.

After buying this car from Serpent directly I do not think I will ever buy another Serpent item even the kits, as if this is the quality of a RTR, I would hate to the quality of the kit parts, as a whole. I have built kits starting with the RC500 and forth other brand kits and have a bunch of RTR cars and truck in nitro form and never in my life have I had such a problem, especially from a company that is know to have the best items. I just don't see it.
After the BS from Novarossi and being a loyal customer over 30 years I decided to remove all my Novarossi engine from my mdles and go with a different brand, why would I promote a crappy company that don't know anything about an engine they supposedly manufactured. I really don't think they manufactured the engine, I think they sourced it out to the cheapest manufacture and placed their name on it.



Now the car runs as it should after rebuilding the car. That's not what anyone should have to go through with a RTR car. What's really sad lets say. a father who really isn't in the hobby buys one of these RTR for his son so he and son can have some bonding time and the car can't even drive 100 feet without falling apart. Just makes Serpents name look like SH** Truck Junk, mud duck junk.

I have a Traxxas RTR 3.3 4 tec on 20% that smokes this junk Serpent Cobra GT on 30% by about 10 MPH more.

NOT ONE DROP OF OIL, GREASE, OR LOCK TIGHT WAS USED DURING THE INITIAL/ORIGINAL BUILDING OF THIS SHIT TRUCK MUD DUCK JUNK CAR. ANYONE LOOKING INTO THE SERPENT NAME BUYER BEWARE HIS 40 YEARS EXP IS A JOKE IN A PROFESSIONAL STANDPOINT. THE SERPENT CO IS OVER IN JAPAN TOO, THE GUY IN AMERICA WHO SAYS HE IS SERPENT REALLY ISN'T AS HE DONT MANUFACTURE ANYTHING HE SOURCES IT ALL OUT.

Dan
I have recently picked up a used 3.1 and sold on my rtr to another racer. with the clutch though i am finding that when tightening the end screw on the clutch bell the unit locks up.
I have multiple shims to use but not sure where to start. Its all good till the last step.
Can you help.

Iain

It seems like there is not enough gap between the clutch end and ball bearing so when you tighthen the screw it pushes down on the bearing. Try putting some shims between the clutch end and the bearing. There should be a little amount of play.

https://cimg2.ibsrv.net/gimg/www.rct...83a2b0454e.jpg

Tried that early no luck using 4 shims to see if it would work. I will have another play tomorrow. I mat try some new bearings also.

It's really difficult to advise without actually seeing the flywheel and clutchbell assembly in person. You could try using a different flywheel collet or adding shims behind the collet to move flywheel forward and backwards. Also try adding shims behind the bearing inside clutch bell. Keep in mind that although they look similar flywheel is different for 811 buggy and gt. You might be trying to fit gt clutchbell on buggy flywheel, happened to me before, doesn't fit properly.

Hope this helps.

Thanks for that. i will try some alternatives that I have as spares

Iain

Iain,
It sounds as though you need to place shims on the Engine shaft. To check.
From the diagram posted above. First, ensure there's one shim between your engine bearing and your flywheel and that the flywheel is right up on this. When you have assembled the bearings and end bell on the engine shaft, stop.
With the last bearing in place, look down into where the last bearing sits,. You should see the engine crank shaft slightly protruding above the last bearing. If it is slightly below, as I think yours might be, you are going to need to place shims (3mm ID, 5mm OD) inside the last bearing, up against the crankshaft.
Place shims here until you get the play you need.
Note. You will find it easier if you place these small shims on the screw after the screw cup (in the diagram above, then the last bearing. Leave off the larger shim. Assemble these as a group into the end bell and tighten. Keep adding the very small shims to the end of the crankshaft until you get a very small, but noticeable (!) bit of play when fully assembled and tightened down.

Hopefully that should sort you out.

Regards
BM

I visited a local hobby store and found someone who knows more about this than me.
Yes 3x5 shims in the end works a treat. happy days.
I did need almost 2.5 mm so used a 2 mm from my 4X tourer spares but will look at changing this as it is aluminium not steel.
I think using the shim behind the collet and between the bearings per the diagram will bring this down.

Thanks to all for assistance.

Another question. With my RTR gt car I used the optional white silver and black spring to firm it up.
Are the standard 3.1 springs equal to any of these.

Iain

SRX8 GT Nitro (600057) is LWB or SWB?

The SRX8 GT gp car is SWB, we only offer the SRX8 GTE in SWB and LWB.
Hope this helps.

Has anybody tried to to run the Serpent Clutch from the SRX GT TQ in the GT RTR model? The RTR runs 48pitch gears but i cannot seem to find 48pitch pinon gears for the SRX Clutch. Perhaps a bell housing from another manufacturer running 48pitch will fit?

Any have issues with 2 speed gears stripping on the cobra gt keep stripping 2nd gear

What causes a bent front drive shaft?
 

I was out breaking in a new engine today in my 3.1 Cobra and after a few tanks I brought her in to check the temp and before I sent her on her way I picked the back up to clear her out and I noticed the front drive shaft has a noticeable wobble , now I have done this in 1/8 buggies but my 3.1 doesn’t have a scratch on her ... what causes a bent drive shaft ..? Not enough play ?