Suddenly Does Not Shift (Good Tune)

[tjstinson]

I have had this issue for weeks (not shifting), and I have inspected the clutch holder closely. Everything was in place on the clutch holder before I ran it recently (the day I posted this question) but I knew that the clutch holder might be the issue. After reading the responses, I am certain. However, I received the new clutch holder in the mail today and opened the transmission case to install it... Wow!

The adjustment screw was missing as was the spring and the ball. It was completely assembled before because I inspected it, but obviously the nut backed out and everything behind it followed. Luckily nothing was thrown into the gears and caused a bigger problem. Each part was laying in the case on a layer of grease.

I installed the new clutch holder and placed a conservative amount of thread lock on the adjustment screw. Hopefully this will prevent the issue from happening again. I also reassembled the stock clutch holder and when I tightened the adjustment screw it seemed to function correctly.

What does this mean? I don't know. I would assume that the spring, after a couple gallons of fuel, needed to be adjusted and compressed dramatically to function properly as it had before. That made the truck start in second gear and left a gap between the spring and screw that was wider than I expected so when I adjusted three turns in, it probably had JUST started to touch the spring and still didn't correct the problem. The gap also might have caused grease to find its way between the spring and screw. Then when the engine ran vibration and adjustments I made only lubricated the path and allowed the screw to back out completely.

No matter- It seems this must be the problem. Weather was too sketchy for a run today to test it, but when I do I will return with my final conclusions.

 

[Rolex]

I can guarantee you just solved your problem but I'm also pretty sure you'll have to tweak the shift point after you get it warmed up. You have no idea how lucky you were that the parts ended up stuck in the grease.
Figuring out and solving the mechanical problems on these amazing machines is almost as satisfying as breaking something else.

 

[tjstinson]

I can guarantee you just solved your problem but I'm also pretty sure you'll have to tweak the shift point after you get it warmed up. You have no idea how lucky you were that the parts ended up stuck in the grease.
Figuring out and solving the mechanical problems on these amazing machines is almost as satisfying as breaking something else.

AB-SO-LUTELY! I was so thrilled that fortune fell my way and I was equally relieved that the issue seemingly has been addressed and corrected.

I will add that I was surprised to learn that when I reassembled the old clutch holder that I could get the spring, ball, and finger to function correctly (at least as I could see without putting it back on and doing a run with it). I expected that something was very wrong or missing that caused the issue, but it may be that the original clutch holder was fine. I just didn't adjust enough because I never expected to have to adjust more than three turns from stock position when it must have needed it.

Kept the old one just in case I get in a pinch, but I expect the solution has been found.

Thank you for all your help!

 

[SMaxxin]

I can't remember if I ever ran aluminum clutch shoes but I'm interested to hear your thoughts after you run with them.

 

[tjstinson]

Well, I still can't get a shift, but I may be hopeless. I get discouraged when I don't see any response and especially when something else gets worse.

I'm running the LSN at stock position and the HSN is in a couple turns but not far. It should be on the rich side, but while doing runs to adjust the new clutch holder, the engine got to 280 degrees rather quick.

After I would stop the engine to make another adjustment on the clutch, the engine was hard to turn over. It was as if the clutch bell was wanting to turn the spur gear like it would if it was trying to turn over in a lean state. I stop the engine with the safety engine stop part upgrade so I have fuel in the carb when it stops running. It should turn over rather easily.

After doing many runs and many adjustments, I couldn't find second gear or a gear change. I wonder if something else is at play here. It am definitely getting the RPMs but I'm either missing the sweet spot or have something else going on entirely.

I know I am rather new, but I know that it isn't my needle settings. It should be rich if anything, but it is seeming rather lean. Perhaps because now it is stuck in first gear. It does seem to slow quickly when I release the throttle. Would running in first at high RPM make the engine leaner?

I'm still wondering what damage I could have caused from the first incident I had out of the box. HPI said they looked it over, but it doubt they opened the engine and checked seals and such.

Without having someone experienced looking at the truck and what it is doing then I am pretty much painting the Titanic. I appreciate all the help and I wish I could have put a period to this thread, but I fear I might be over my head on this and I don't really have much else to go. My respect to all those that endured similar pains and pushed through it. I'm having the most obscure and unexplainable issues one right after the other and this kit is relatively new. More than that, I have the tuning in a safe spot, but I get temps consistently over 250. I don't punish the truck and I don't stress the parts. I still can't wheelie, lost my shift, and have a thousand dollars or more in the truck and parts, but nothing to show for it but frustration. I haven't had this truck EVER running as it should. I spent a week on the tune and then met one obscure issue after another until now when I just want to walk away.

Thanks again everyone. I do appreciate it. I might need to just step away and get a clear head.

 

[tjstinson]

What would a mod charge to look my truck over? I mean, I would pay to ship it to and back and have a mod look it over and tune, adjust, and/or diagnose the issue. I don't really want to throw much more money into it, but if someone was interested and quoted a fair price, I would be willing to pay up front via PayPal.

I would want the truck to wheelie, shift properly, and run under normal conditions without temps in excess of 250 degrees. If someone could do that, I would pay them for their services. If a problem is found that prevents any or all these things that would require new parts, I would need to be contacted before making those purchases and replacements. Then we could adjust the price accordingly or send it back to me so I can do the replacements myself. It would still mean one would receive the initial up front service payment for accepting the job, diagnosing the issues, and fixing the issues they could without part replacements. :\

 

[SMaxxin]

It was as if the clutch bell was wanting to turn the spur gear

It sounds like a clutch shoe dragging in the clutch bell, this would make it hard to start and would want to stall at idle. Make sure the shoes and springs are installed correctly and that a spring did not break.

 

[tjstinson]

It sounds like a clutch shoe dragging in the clutch bell, this would make it hard to start and would want to stall at idle. Make sure the shoes and springs are installed correctly and that a spring did not break.

I will definitely do that. I thought everything was installed correctly, but it doesn't hurt to look at it. Perhaps there is something that is causing my clutch shoes to malfunction as they are brand spanking new. I just installed them, but this starting issue was present before. Maybe it is one of the problems that what caused the stock shoes to need replaced.

Thank you!

 

[Rolex]

What would a mod charge to look my truck over? I mean, I would pay to ship it to and back and have a mod look it over and tune, adjust, and/or diagnose the issue.

Not what we do here. Shipping is costly since they are large and heavy, but just bear with us and we'll get you going.
Paying someone to do it might get it running perfectly but you would have learned nothing along the way should you encounter the problem again.
Tuning is also affected by altitude, temp and humidity, so someone tuning in Florida would not be able to properly tune for Denver.
Be patient, stay with it, do what you're told, answer the questions and you'll soon be high on exhaust fumes.

 

[tjstinson]

Not what we do here. Shipping is costly since they are large and heavy, but just bear with us and we'll get you going.
Paying someone to do it might get it running perfectly but you would have learned nothing along the way should you encounter the problem again.
Tuning is also affected by altitude, temp and humidity, so someone tuning in Florida would not be able to properly tune for Denver.
Be patient, stay with it, do what you're told, answer the questions and you'll soon be high on exhaust fumes.

10-4.
I don't want to give up. I just don't have experience to compare what I should be looking for or what I should expect. I know the tune is solid, but that is after a lot of trial and error. However, I know a tune is rather relative in the hobby.

Just to give some more details... it starts right up after sitting for a bit. The starting issue I saw today was happening after I stopped the engine and then a few minutes later tried to get it going again. At one point it wouldn't start at all so I changed glow plugs, tried a different glow plug lighter, checked the fuel line, and then decided to just take it inside and let it sit for awhile (the temps outside was 50 degrees and I thought it might be aggravating whatever issue I was having). After it sat for an hour I tried it again and it started right up.

I would have thought it was flooded, but it didn't act flooded. When my truck is flooded it just slips the gear in the roto start and it sounds a lot different when trying to turn over.

My thing with having someone experienced look at it is based on the fact that I keep chasing obscure problems and never getting one fixed before I run into another one that is relatively or completely unrelated. I'm not certain I do not have an air leak. I'm not certain I am actually fixing anything. I am generally very logical, but admittedly not mechanically inclined and I don't have enough experience to rule anything out. I am looking at the truck and just overwhelmed because I don't even know how to explain the nature of the problem well enough to get the solution.

For heaven's sake! I never even got this thing to do a wheelie yet! I finally got the tune right, I adjusted the spur gear and tightened it and I never saw a wheelie when suddenly there was no shift just when I thought I was getting somewhere. I can't be missing the tune that much. Something else has to be at play here.

 

[Alexander_0_1]

The last one sounds like a used up piston/sleeve combo. Before I rebuilt my axials they were doing the same thing. I could run them until they heated up and then they wouldn't start. Until I left them for a few mins.

If you look inside the exhaust port you should be able to see if the outer coating is gone, if it is you should see a brass like colour.

 

[tjstinson]

The last one sounds like a used up piston/sleeve combo. Before I rebuilt my axials they were doing the same thing. I could run them until they heated up and then they wouldn't start. Until I left them for a few mins.

If you look inside the exhaust port you should be able to see if the outer coating is gone, if it is you should see a brass like colour.

On a new truck?!

 

[Alexander_0_1]

Depend on how you tuned and how hard you play, but ya on a new engine!.....especially a stock engine, they're only designed to last long enough to get you hooked, and then your buying parts like a madman like the rest of us.

 

[tjstinson]

Depend on how you tuned and how hard you play, but ya on a new engine!.....especially a stock engine, they're only designed to last long enough to get you hooked, and then your buying parts like a madman like the rest of us.

Well, I will take a look at it. I have a hard time believing that what you say is typical as many people use stock engines for years. I have not even put two full gallons through the engine, though I did have an incident that could have damaged it.

There are discolored spots on the piston, but those were present since the incident I often refer to from my initial post. I took my new truck from the box, started it, and before I could understand what was happening I was watching my truck go directly into full throttle because the throttle trim was set 100%. I sent it to HPI, they say they looked it over, but I have my doubts that this didn't cause damage as it completely melted and chewed my spur gear to pieces.

Perhaps I should call HPI and tell them that my issues are stemming from this. Maybe send it to them again, but I doubt I will get any help.

Given the issues I have had from the start, if I have to shell out $250-$300 for a new engine, I will just walk away. I don't think I have it in me to put that into a hobby I have yet to benefit from. I really don't even want to think that way, but I would be more likely to just by a Hyper 7 than to pour more money into this truck that has already taken more money than I ever dreamed to spend and get little return from.


I don't mean to turn my nose up to help. I will take your advice and give it a look.

 

[tjstinson]

I pulled off the clutch bell gear. Brand new aluminum shoes, that haven't even seen a full tank, are shot. The aluminum engine plate is bent. The two bearings inside the clutch bell need replaced.

I think this all stems from "the incident" and I will plead to HPI to take responsibility for something they already took responsibility for, but never fixed. They were empathic once for the throttle trim mistake, but I think they underestimated the damage because when they tested it the parts were still very new and holding up, but after a few tanks the advanced wear began to compound to the issues I have seen from the start.

I have never seen a wheelie. I lost a shift out of no where (was there one day and gone the next) and I have never been able to make the engine rich enough to stay below 250 after a few minutes of bashing.

I am one to take full responsibility for what I have done. If you knew me personally, you would know that as well. I, sometimes to a fault, will assume blame for even the possibility of my involvement in wrong doing. However, I could not have been more careful and deliberate from the start. If I did anything wrong, it was when I assumed that the factory sent the transmitter with the throttle trim set to 0. I would even admit that I am new and perhaps that is responsible for not shutting down the engine faster when it was accelerating inexplicably.

I will call HPI-Racing (Hobbico) tomorrow and plead my case kindly and patiently. I don't have much hope they will go to the length (at least at first) that I believe is fair, but I can't reasonably put another dime down to fix what's visibly damaged when it seems to only mask the real issue that I have yet to diagnose, but was present from the beginning.

I am very discouraged. A bit ashamed of how naive I have been. I am even embarrassed that I did not do this sooner. I also hate it if I have wasted anyone's time. I assure you that your kindness was still just as valuable to me for all the right reasons. Thank you. I will update as often as it is relevant.

 

[SMaxxin]

Keep your chin up Bud, anyone that learns nitro with only the internet as help has struggled as you are.

 

[bobaloohoo]

Keep your chin up Bud, anyone that learns nitro with only the internet as help has struggled as you are.

couldnt have put it better myself. Dont let the hobby get you down, fixing stuff and learning is half of the hobby for everyone, once you learn, you can fix without question in the future. just take it and stride

 

[jose.28]

This truck (HPI Racing Savage X F4.6) is fairly new (purchased in February 2014) and I had a good tune and shift point established on it until recently when it suddenly (overnight) would not shift to second.

I realize everyone has their own idea of a good tune, but I can only ask that you give me the benefit of the doubt as to explain the tune might only lead to discussions that divert from the what might be the actual problem.

This might get murky, but I am going to explain some things that might have attributed to the problem, but not necessarily. I feel, however, to omit these details might prevent one from coming to the right conclusion.

First, when I started the truck out of the box, the throttle trim was set to 100% on the transmitter. Before I could understand why it was seemingly lean and the wheels were increasing speed, it was too late. A spur gear was melted and smoke billowed from where the spur gear and bell gear mesh. The spur gear was also stripped of teeth and it is anyone's best guess as to what damage this could have caused the piston and sleeve.

I had the truck shipped to HPI and they say they looked it over. They did report that the truck had a good shift and that everything looked fine. I doubt they opened the engine, but either way I have compression and combustion. The engine seems to have survived.

I ran it for weeks following and until recently, with the exception of not seeing wheelies, I felt the truck was operating fairly well. A couple weeks ago it was shifting and I put it up for the day. The next day I took it out and no shift. I also noticed that the low-end torque was leaving much to be desired, but it is possible this was always the case since I got it. The absent or early shift was completely new to me.

One thing I hadn't considered to be damaged from the time I first started the truck and blew the spur gear, but should have, was the clutch shoes. Well, they went out this week and when I was replacing them they were horrible. I suspect that heat generated from the first run melted the spur gear and certainly the shoes. I should have checked them when it happened, but I assumed HPI would have looked it over as this was a concern.

I installed the HPI aluminum clutch shoe upgrade. I hoped that this would fix the missing low-end torque (the truck moves, but is requires more throttle than I would think necessary in the grass and has NEVER popped wheelies).

I have tightened spur gears. I have tuned it to the point that I reach temps of 270 and 280 and have to back off. I get a decent speed without the shift and a fair take off when I mash WOT, but early power and a shift is missing. I am almost CERTAIN the RPMs are present to pop into 2nd.

I have adjusted the transmission screw (yes, the right one) and I saw NO difference at all. I moved it back to stock position- still no difference. Turned it IN 3 turns- nothing. I tightened the grub screw that holds that gear in place as well. I have not checked to see if it was broken, but it is in there firmly. The finger on the transmission gear seems fine too. At first I thought it was broken because it was angled to a point, but I have looked at the stock fingers and they are the same.

I am at a loss. I have checked diffs front and back. I have smooth movement in the transmission gears. I have a stock tight drive line from rear to front as best I can tell. There isn't slop.

What am I missing? What could be going on? Does the overheating from the first start come into play in this? Is there something else that could have been damaged like the clutch shoes that I am not thinking of?

Humm. I must ask if you broke in the engine. I see you didnt say you did and that can have a big impact. So big that you will be lucky to get a gallon out of it before you lose power. And if you lose power then of course it wont shift.
And yes a you can tune to 240 or what ever it may be but if you dont fine tune your low speed you will never get a good strong take off witch is important to aquire a shift as well.
But if you did not do a proper break in then your motor is shot and must re sleeve it along with a new piston. Or just get it repinched.

 

[tjstinson]

Humm. I must ask if you broke in the engine. I see you didnt say you did and that can have a big impact. So big that you will be lucky to get a gallon out of it before you lose power. And if you lose power then of course it wont shift.
And yes a you can tune to 240 or what ever it may be but if you dont fine tune your low speed you will never get a good strong take off witch is important to aquire a shift as well.
But if you did not do a proper break in then your motor is shot and must re sleeve it along with a new piston. Or just get it repinched.

I did break in my engine. I followed their instructions to the letter. The problem was that they had the throttle trim set to "Full" when I started the truck for the first time. So it was put through a lot of stress before I could even begin break in. After that happened, I replaced the spur gear, started the truck, and followed the prescribed break in.

 

[jose.28]

Ok cool. I know you know this now but be sure to check the electronics befor every start up. I've had my radio get messed up and found setting where off. My kids like to mess with my stuff lol.