Need some expert advice/help!

[k3mist]

TLDR; Top end slow. Slipper clutch replaced with heavy duty. Shift point adjusted. Already leaned out to the max.

Long story short my Revo 3.3 is not performing that well after ~11 tanks. I've read it takes some time for the 3.3 to open up but it should be performing better than it is right now. I've tried everything and I'm at a bit of a loss. The main issue is on the top end/high gear.

I first noticed in the break-in on my 5th tank she would not shift into high gear. I finished the break in and started looking into the issue.

After lots of research I've done the following;

The pads on the slipper clutch were failing already so I replaced the slipper clutch with the heavy duty one.

I've adjusted the shift point which is now allowing it to get into high gear. But its still slow in that gear and not hitting high speeds. It takes about 3-4 mississippi's at full accell to hit high gear so I think i have a decent spot for the shift point.

It would not get into high gear on Traxxas 20% until I leaned the HSN. This is the part thats bothering me most because I feel like she's a little bit leaner than she should be right now and I have no room to play at all on the HSN to get her into high gear.

I know there is something else going on because this is my 2nd Revo and I'm comparing it to my first.

My first Revo I had issues keeping it out of 2nd gear on break in when I started the 4th tank. The thing was running strong and hitting 40mph np.

I got into RC about 3 weeks ago and I was unaware of the brake pad issues on these RC's. On my ~7th tank or so a pad fell off while I was doing some high speed runs and she got tore up bad. No brakes at all at full speed and that was that. I replaced everything that broke and put a few more tanks in her, but the wreck apparently tweaked the chassis and no matter what I did she wouldn't drive straight anymore.

In hindsight I should have kept the engine from that truck when I exchanged it but water under the bridge.

I'm going to put another 4-5 tanks in her tomorrow when I wake up but I could really use some expert advice. What else to look at or what else can be wrong? Seems like something is off big time and I'm not sure what else could possibly be set incorrectly when it left Traxxas?

 

[Certified Mike]

I would recommend going back to the beginning in this case... Keep the truck in first and get the engine tuned properly. Be sure that you are checking your running temps.
Lots of ppl have different opinions about running in the cold. Here, today it's too cold to run IMO. Yest, it was a beautiful day excepting some wind and the salt/sand. Anyways... That is another thing to consider. What surface are you running on while you're trying to tune? When you've got the truck tuned back down to 1st gear only and have checked the temps, making sure you've got an area to run in that is smooth and isn't causing too much resistance (this is just for tuning purposes) post back with your results. You Def want to make sure that you have the truck tuned for single speed before you move on so please, be sure the truck isn't too leaned out, running too hot or cold etc.
Keep in mind, if you blow the engine, 2nd gear isn't gonna be ANY fun!

 

[k3mist]

....

Thanks Mike! I retuned twice the last time I ran it starting at 4 turns out on the HSN. The last tank it got up to 260 so I'll need to richen it before I run it again. I'm in FL so no need to worry about the cold!

I did the break in and tune on pavement.

I might take the tranny out and see if anything is off from the factory. I read online that people found issues in brand new trucks before. Who knows?

Unfortunately I woke up late this morning and didn't have a chance to run it today. But i will before the weekend is out.

If I blow this engine it would just give me an excuse to drop an OS in

 

[Certified Mike]

Ok... Florida huh??? You Def need some direct help on your truck... Fortunately for you, I HAPPEN to own the same truck so here's what we gotta do...
I'll need for you to forward a first class ticket... I'll need a daily spending allotment as well... So get all that in place for this evening... I think you get the idea.


Ok... So back to reality...
Before you go taking the truck apart, I strongly urge you to focus on getting your truck to run right on the 'first gear only' set up. Where you have got the truck to shift in and out,, although you're not 'there' to where you are happy with everything, it seems as tho the 2 speed portion of your trans is working. No need to dig into the trans... Yet.
With the number of tanks you have run, it sounds like you have completed the break in process. Check these threads out and make sure what you did for your break in is similar. There is good info here to get you thru your engine tuning as well.

https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/

https://www.rcnitrotalk.com/forum/threads/nitro-rc-beginners-guide.68224/

Also check out this thread

https://www.rcnitrotalk.com/forum/threads/clutch-installation-and-rebuild.109150/
The last post has some pics '"x'd" out but it has good info on how to set and check your clutch set up.
If you have the time, search thru the forum. There's LOTS of good info posted here that will almost certainly help you thru where you are.
You definitely want to make sure you take on one thing at a time. Start at the beginning with getting your break in correct, then work out the tune. Follow that with your clutch setup and finally, get the 2 speed setting correct. Don't get ahead of yourself or you will find it very difficult to determine where the issues are coming from.
Just to make sure...
What other changes have you made to the truck? Is your gearing all stock still?

A couple other things I just want to mention. All engines and carb settings are unique. Your settings will change daily, hourly sometimes depending on the ambient temps and weather. Once you've got your tune set its only a little tweak here and there usually.
Anything you read as far as setting the HSP or LSP are just guidelines. There is no setting that will just work unless you get VERY lucky. (example: Set your low speed needle from closed position, loosened 4 complete turns) The factory settings that you get are set for break in usually. This means that it will likely get you started and are typically set on the rich side for break in.
Your 260° temp is about as high as I like to run. Aside from the temp itself, I ALWAYS make sure there is a healthy stream of smoke from the exhaust. This means you have cooling and lubrication coming from the fuel. THAT is most important IMO!
Ok, so you've got plenty to read and I'm sure there will be questions. Let me (us) know how this all goes and again, when you've got the truck up and running again!
While I do love the idea of dropping in a nice O.S. plant in there, the 3.3 really isn't a bad engine. It gets the job done for sure and is a great engine to learn on before you step up to the extea, power, speed and COST!
Ok, so reply back and we'll go from there.

 

[k3mist]

...

Haha! Yeah Florida is nice. I'm originally from up north and I do not miss it at all!

I'm pretty confident it is running good in first gear. The temps are right there in range and it's sounds good. Nice trail of smoke when accelerating. The idle seems pretty solid as well. Starts up easy and it's not stalling, even when I flipped it a couple times.

I was going to run her this morning but it's raining. The LEDs I installed don't have sealant on them yet. Have to make a run to the hardware store and seal all that off. Hoping it stops raining by this afternoon. Still pissed off I slept in yesterday. It was perfect all day.

For the break-in I followed the Traxxas method. Made sure the piston was at BDC as well in-between tanks. Have the whole thing memorized at this point actually.

I haven't made any changes to the gearing. Only made adjustments to the 2nd gear shift point. All of that is still stock. Only stuff I changed out was the a arms, push rods, front toe arms, front/rear springs. Added the wing, skid plates, and tires.

This is mainly why I'm asking for help, as far as I can tell with my limited experience. Having read everything I can find on the subject, watching YouTube videos, and also having that other Revo first and using it as a comparison.

I'm just lost at this point as to what could be wrong. It makes me feel like either there is something wrong with the trans or the engine itself has an issue from Traxxas.

I followed everything to the T. And I read/watched before I attempted anything myself.

I'm confident I can get this thing running right. As long as it's not an issue with the engine itself, whatever is causing the top end on this truck to be slow can be fixed.

I'm pretty sure the engine has a few more tanks before it wakes up completely as well.

 

[Certified Mike]

Ok. So if the engine is Def running right, no air restictions in filter or fuel lines, muffler line is pressurises fuel tank (so there is no high speed lag at all)... I guess the next thing I would look at would be to make sure all the drivetrain components are spinning freely. I would stillavoid taking the trans apart until you've identified it as an issue. Be sure the brake hasn't overheated and warped or anything weird like that too

 

[k3mist]

...

It's starting to wake up!

I ran 4 or 5 tanks through it yesterday after the rain chilled out and it was running pretty strong on the last two tanks. I waited until most of the pavement dried up. It was about 60f. Ran it again today about an hour ago. Leaned it out some more since its about 70 and it seems to be running stronger.

No idea why this engine took so long to wake up compared to the Revo I had only a week prior. I did the break in exactly the same. I mean, I'm about 15-17 tanks in now. I didn't get a chance to check temps but from the sound and smoke trail it seemed good.

Unfortunately I think I busted one of the bearings in the rear left axle carrier when I was jumping it Its making a clicking sound when it does a full rotation. Doesn't sound too bad but not gonna leave it

 

[Certified Mike]

Sounds like you're getting it worked out. Glad to hear it! Yeah, Def make sure you get the bearing worked out. If you have other issues let us know!

 

[k3mist]

Sounds like you're getting it worked out. Glad to hear it! Yeah, Def make sure you get the bearing worked out. If you have other issues let us know!

I have the bearings from the stock axle carrier still so I'm gonna swap those in when I get some free time. Hopefully they are the right fit for the RPM axle carrier.

 

[cbaker65]

It's starting to wake up!

I ran 4 or 5 tanks through it yesterday after the rain chilled out and it was running pretty strong on the last two tanks. I waited until most of the pavement dried up. It was about 60f. Ran it again today about an hour ago. Leaned it out some more since its about 70 and it seems to be running stronger.

No idea why this engine took so long to wake up compared to the Revo I had only a week prior. I did the break in exactly the same. I mean, I'm about 15-17 tanks in now. I didn't get a chance to check temps but from the sound and smoke trail it seemed good.

Unfortunately I think I busted one of the bearings in the rear left axle carrier when I was jumping it Its making a clicking sound when it does a full rotation. Doesn't sound too bad but not gonna leave it

It sounds like you havin a good time with it!...

You can do a quick spit test on the head ,if it sizzles off with then a few seconds ,then it maybe too hot!
I think about 270 deg. you should be good!

 

[Certified Mike]

I think the RPM offered an oversized bearing carrier for the revo. Guess test fitting will be the best way to figure it out. I am not sure if RPM made a stock size as well. If the bearing in an RPM part, it should also carry the lifetime guarantee.

 

[olds97_lss]

The RPM bearings are larger than the older revo bearings. Pretty sure the RPM lifetime warranty doesn't include the bearings either.

That said, I got a late model e-revo and it has larger bearings in the stock carriers. I still used the RPM bearings when I put RPM on it all around (carriers/arms front, true-track on the rear). I found out the bearings were larger when I busted a stock carrier and used one from an old revo I had in my parts drawer. I tried fitting the newer stock bearings and they wouldn't fit. So I guess traxxas finally upgraded something worth while. lol

From RPM's site:

• Outer bearings are 6x15x5mm (stock is 6x12x4mm).
• Inner bearings are 12x21x5mm (stock is 12x18x4mm).

Looking at the parts diagram for the old 2.5 revo, it had 6x12 and 12x18, but the new ERBE has 6x13 and 12x18, so I guess only the outer bearing is larger than the old one, but neither are as large as RPM's. I had one of the RPM bearings freeze up on me after running in snow/wet a few times. I just got my order from www.FastEddyBearings.com today in the mail to replace them all. I was able to get mine to free up, but it took a couple pairs of pliers and oil to do it. I'll replace them all at some point now that I have the bearings on hand.

 

[k3mist]

I think the RPM offered an oversized bearing carrier for the revo. Guess test fitting will be the best way to figure it out. I am not sure if RPM made a stock size as well. If the bearing in an RPM part, it should also carry the lifetime guarantee.

Yeah, its a different size unfortunately. I took the bearings out on the axle and found which one it was. I think it was small piece of dirt that somehow got inside the bearing case.

The bearings themselves seem fine when I took the side off the bearing and its only in a very small part of the rotation in the same spot that there is more or less a "click/scratch" sound which you can also slightly feel when rotating the bearing. I didn't have bearing oil at the time so I put some silicone oil in the spot and it seems to smooth out when I did that.

I bought some high speed bearing oil off amazon that has good reviews. I'm gonna try and flush it out, hopefully. I don't think anything is wrong with bearings themselves from what i could see. I'm just hoping at this point that whatever did get inside didn't make a groove. I'll find out when I try and flush it.

...

Thanks for the bearing sizes! Yep, when I went to swap them with the stock they are clearly larger. I went ahead and ordered a ceramic bearing kit for the Revo off amazon. Still waiting for them to show up. Hope they have the right sizes in there for the RPM replacement.

 

[Certified Mike]

Just a thought, as @olds97_lss mentioned, you may want to pick up an extra or 2 if the finances allow. I am also a believer in having the parts 'in stock'. No waiting for the delivery etc. It seems that these bearings are an issue. Buying the RPM upgrade was a wise decision.

 

[k3mist]

Just a thought, as @olds97_lss mentioned, you may want to pick up an extra or 2 if the finances allow. I am also a believer in having the parts 'in stock'. No waiting for the delivery etc. It seems that these bearings are an issue. Buying the RPM upgrade was a wise decision.

I'm slowly building a small collection of extra parts. I have RPM A-arm replacements on the way and the rear arms will have bearings in the package. And got that pack of bearings coming too. Also got some extra slipper pads, brakes, rockers, push/toe rods, screws, etc. One of the issues right now is not knowing what breaks more frequently than the others because those I wouldn't mind to have 2 or 3 of.

 

[Certified Mike]

The only thing I have broken to date from impact was arms. My own stupidity took out a couple trans gears. That's it for me. I'd say you're pretty well set for now.

 

[olds97_lss]

I'm slowly building a small collection of extra parts. I have RPM A-arm replacements on the way and the rear arms will have bearings in the package. And got that pack of bearings coming too. Also got some extra slipper pads, brakes, rockers, push/toe rods, screws, etc. One of the issues right now is not knowing what breaks more frequently than the others because those I wouldn't mind to have 2 or 3 of.

If it's a bearing kit specifically made for the revo, odds are, it will only have bearings to replace all stock sized bearings. Which means, you need to order some backups for your RPM carriers.

 

[k3mist]

If it's a bearing kit specifically made for the revo, odds are, it will only have bearings to replace all stock sized bearings. Which means, you need to order some backups for your RPM carriers.

Yeah, after I posted I went hunting and got ceramics on the way now.