Revo 3.3 Seized

[CreepyQuarryCrawler]

Hey everyone.
So today I made a trip out of town to a track. I should have left well enough alone but I thought I would try some tuning. The truck ran for a total of five minutes before it burbled and shut off. The EZ Start wouldn't get it going again.
After getting home I pulled the head to find the piston stuck at TDC. After using a 5/8 dowel to free it up I put it back together and the starter spun for a sec then locked again. It looks like the sleeve and piston are now best buds.

After pulling the head again it looks like the sleeve is wanting to come out with the piston. Now it's above the deck by about a 1/16th.

I have a feeling TRX5290 is in order?
(New piston and sleeve)

 

[CertifiedMike]

Hey everyone.
So today I made a trip out of town to a track. I should have left well enough alone but I thought I would try some tuning. The truck ran for a total of five minutes before it burbled and shut off. The EZ Start wouldn't get it going again.
After getting home I pulled the head to find the piston stuck at TDC. After using a 5/8 dowel to free it up I put it back together and the starter spun for a sec then locked again. It looks like the sleeve and piston are now best buds.

View attachment 276930

After pulling the head again it looks like the sleeve is wanting to come out with the piston. Now it's above the deck by about a 1/16th.

I have a feeling TRX5290 is in order?
(New piston and sleeve)

How much is a new piston and sleeve vs trade in motor from Traxxas?

 

[CreepyQuarryCrawler]

How much is a new piston and sleeve vs trade in motor from Traxxas?

That's a good question.

The piston and sleeve are 100 + 12% tax
A new engine is 300 + 12% tax

I'll call the LHS today and see what a trade in is worth.

 

[tudordewolf]

That's a good question.

The piston and sleeve are 100 + 12% tax
A new engine is 300 + 12% tax

I'll call the LHS today and see what a trade in is worth.

There's a piston and sleeve on Ebay for ~$70, and kitbreakers sell engines for less than half the "crate engine" cost, albeit without some accessories, but the swap would be easy in your case.

 

[CreepyQuarryCrawler]

There's a piston and sleeve on Ebay for ~$70, and kitbreakers sell engines for less than half the "crate engine" cost, albeit without some accessories, but the swap would be easy in your case.

Thanks for the links!

The engine comes up as $212 on my end with part cost plus shipping. I am sure there would be fees taxes and possibly duty/tariff related charges.

I've been down that road with ebay before with a TRX VXL3m motor. It looked cheaper until it landed then it worked out to the same cost or more. I have to be very careful what I bring in.

 

[CertifiedMike]

https://traxxas.com/media/wysiwyg/b2cusa/documents/200305-Power-Up-Form-with-Form-Fields.pdf

This is the trade in option from Traxxas that I mentioned.

 

[CreepyQuarryCrawler]

I knew I had read that somewhere. I should be able just to take the core in and get a discount.

 

[CertifiedMike]

View attachment 276941

I knew I had read that somewhere. I should be able just to take the core in and get a discount.

Good deal! Hopefully the shop will honor the pricing and have you all fixed up in one visit.

The pricing is what keeps me most interested in this program. If you opt for this, plz post about your experience.

 

[CreepyQuarryCrawler]

Good deal! Hopefully the shop will honor the pricing and have you all fixed up in one visit.

The pricing is what keeps me most interested in this program. If you opt for this, plz post about your experience.

I have never used it but it's cool they offer it with almost all their electronics. Even the old radios!

I'll keep the tread updated.

 

[easy rider]

Why would you trade it in? It appears it needs to just be left at bdc when you quit running. Am I missing something.

 

[CreepyQuarryCrawler]

The engine will no longer rotate.
I broke the piston and sleeve apart once using a dowel because I couldn't turn it by hand.
When I rotated it again it grabbed the sleeve and wanted to bring it up with the piston.
I forced it down again using the dowel.

This was all with after run oil of course.

Then I reassembled it with the piston at bdc, used the EZ Start and it instantly bound up.

I don't know much about nitro beyond breaking this in and using it a few times.

Now the sleeve is above the deck.

I, in all honesty, could be missing something.

Just took the head off again to look at where it jammed up.

Using the dowel I was able to gently push the piston back down.

I have a feeling that mark all the way around the cylinder wall is the problem.

So like a mini honing tool?

 

[CreepyQuarryCrawler]

Man. The last few years being a Canadian has been such a kick in the teeth. Our fridge broke,14 months in. No coverage here in Canada. In the US, 5 years.

So my LHS basically told me it's not worth it to pursue the trade in program due to taxes and tariffs.

I called TRX Support to double check just to make sure my LHS was being straight with me. They 100% were. It's cost prohibitive to send the motor to the US.

The eBay one listed doesn't ship to Canada.

 

[desmobob]

What a bummer!

I'm kind of surprised at the whole seizing situation. I've run a LOT of brands and sizes of ABC nitro engines in RC aircraft over the years and I've never had one seize. I've only had one nitro buggy and, while I'm sure I've had it quit do to being lean (probably more than once), I never had it seize to the point of being permanently damaged. Maybe I was just lucky... or maybe you were just unlucky? Is this common in ground vehicles?

 

[ohsnap]

$110.0 on the Traxxas trade in program isn't a bad deal.

After getting home I pulled the head to find the piston stuck at TDC. After using a 5/8 dowel to free it up I put it back together and the starter spun for a sec then locked again. It looks like the sleeve and piston are now best buds.

After pulling the head again it looks like the sleeve is wanting to come out with the piston. Now it's above the deck by about a 1/16th.

Now the sleeve is above the deck.

Engines that have lost compression don't stay stuck at TDC - nor lift the cylinder as you described.
So at his point, being stuck at TDC or lifting the cylinder above the deck isn't a bad sign to me.

That ring may be part of your problem and given how the top of the piston looks, I suspect that the engine may need a good cleaning.
I don't believe that honing is the answer.
Try using denatured alcohol and a Q-tip to address the ridge inside the cylinder (try to clean the ridge and the top of the piston in place.).
If the ridge is gunk, it should clean up easily.
If the ridge is metal and doesn't clean up, you're probably playing taps.

If I was being OCD, I would pull the piston and cylinder and drown them in denatured alcohol and addressing the blocks internals too.
I would pull the carb and flush out the bearings (OCD or not).
The fast way is filling the block with the alcohol and turning the crank and seeing how it feels (OCD has me pulling the crankshaft and submerging the block - but there's extra steps to avoid cross contamination as- you don't want to introduce outside dirt to the internals).

I'm a roto-start and not an EZ-Start guy, but how is the battery?
A weak battery can leave you stuck at TDC - as can a slipping OWB.

 

[CreepyQuarryCrawler]

$110.0 on the Traxxas trade in program isn't a bad deal.
View attachment 276958






Engines that have lost compression don't stay stuck at TDC - nor lift the cylinder as you described.
So at his point, being stuck at TDC or lifting the cylinder above the deck isn't a bad sign to me.

That ring may be part of your problem and given how the top of the piston looks, I suspect that the engine may need a good cleaning.
I don't believe that honing is the answer.
Try using denatured alcohol and a Q-tip to address the ridge inside the cylinder (try to clean the ridge and the top of the piston in place.).
If the ridge is gunk, it should clean up easily.
If the ridge is metal and doesn't clean up, you're probably playing taps.

If I was being OCD, I would pull the piston and cylinder and drown them in denatured alcohol and addressing the blocks internals too.
I would pull the carb and flush out the bearings (OCD or not).
The fast way is filling the block with the alcohol and turning the crank and seeing how it feels (OCD has me pulling the crankshaft and submerging the block - but there's extra steps to avoid cross contamination as- you don't want to introduce outside dirt to the internals).

I'm a roto-start and not an EZ-Start guy, but how is the battery?
A weak battery can leave you stuck at TDC - as can a slipping OWB.

View attachment 276957

I can definitely try cleaning it.

The battery was fully charged with my full size charger. It initially charged above rated capacity and then I recently did a complete discharge/charge cycle of the pack.

It's applying a lot of torque to the EZ Start gear box so I don't think it's the battery.

The $110 is USD, it would need to be exchanged to CAD. Then shipping, duty and taxes. The rep from TRX said it brings it really close to the 300 retail here in Canada = not worth it.

There is one piston and sleeve left at my LHS. I had them out it aside for me until I get a chance to get down there.

 

[CertifiedMike]

https://jennysrc.com/collections/traxxas-revo-3-3-53097-4/products/trx-3-3-engine-revo

Don't know if you saw this or would rather just stay with a repair on your current engine.

Seems like a great deal!

 

[CreepyQuarryCrawler]

@CertifiedMike
Thanks for the link.

That comes back at $190 CAD. I'm assuming there will be shipping, taxes and duty/tariffs on it when it lands .

 

[CertifiedMike]

Jennys is in Canada. I'd verify all that with Ted.

 

[CreepyQuarryCrawler]

Jennys is in Canada. I'd verify all that with Ted.

I can reach out but everything is in USD pricing and in shipping they mention USPS several times with zero mention of Canada Post.

* I emailed for clarification on where the item would be shipping from.

 

[ohsnap]

There is one piston and sleeve left at my LHS. I had them out it aside for me until I get a chance to get down there.

Don't forget a conrod if you go this route.

I hold out hope for your current engine.
How much fuel has been through it?
Who knows, "the ring" at this point may be causing excess pinch.
Have you tried pre-heating the head?
Besides giving it a good clean, you have that option.
I've had engines that the Roto-start couldn't turn over unless they were pre-heated