scottyfusion

My Feedback: (1)

just got my brand new mach .26 back from horrizon. it took 3 weeks to get it back (and a lot of phone calls and headachs!!!). i would sugest talking to doug or shane at horrizon. anyhow went to take out the washer and suprise suprise....no washer. it came with a pull start so i had to put the roto start on it but it uses the same backplate. so here is my ? why would they even put the washer in ther i mean the pull start uses the same parts internaly it just dont make sense!!!

does anyone follow what im saynig here??


also one more thing. the people that have opened their engine will follow this.. the spring in the roto start (between the roto start and the backplate) puts constant lateral presure on the "washer". not only is it spining at 39k and hot as h@$% it also is being squeezed by said spring!!! im not a engineer or anything but even i could tell u that sooner or later that little peice of metal we all know and love as the washer WILL explode!!!!!

well thats all i feel much bettr!

4wheelin

I read the pullstart version has no wahser.

jefx

The pullstart version doesn't have a washer. The washer is there to take out play in the roto-start version and to keep it from rubbing the conrod.. Apparently the roto start wasn't built to the correct specs, and instead of scrapping all the rotostarts, they used a washer to make up for the bad machining.

dankcharlie

THANK YOU!, Thanks so much for the warning i have about 1 1/2 gal. through it and i was not noticing any wear on the washer, well today 1 tank later my 1 way went so i took a look and low and behold there it was just dangling on the edge!

jefx

No problem, that's what this thread is for.

cpirao

Just Spoke with Steve at Horizon Hobbies who in-turn spoke with an engine technician, and He confirmed that removal of the washer does not, in itself, void the warranty.

Can anyone confirm whether the backing plate is sealed by way of a gasket or an o-ring, or some other means of a sealant.

Thx much

dankcharlie

nope no seal on the backplate!

cpirao

How can there be no seal? Are you telling me that the metal plate is sitting on metal? How does the factory ensure an airtight fit?

Eracer76

I just got my new LST #9302 on Monday, guess what?
It still has the washer! Mine was a nice and thin silver washer just waiting to burn up, so...... I removed it!

The back plate does have a seal!! It is a rubber O-ring style seal. I also cleaned out some metal shavings I found, added some good RTV silicone to the back plate and carb to seal them up better.
Now its ready to start for the first time, I cant wait!

jesterrc

There is a small black o-ring at the intersection of the flange and the round part of the back plate that extends into the motor. I didn't use any sealent but it definitely won't hurt. I read that after the engine is broken in you could remove the washer. I had between 5 and 6 gallons of fuel (Blue Thunder) on mine before I took it apart and it looked beautiful but I removed the washer any how. Neither me nor any of my buddies have had this problem. Could the fuel or lubricant have anything to do with it? I'm not smart enough to know more than the instructions so we have all used Blue Thunder as they suggested. Just a thought. By the way, the car guy at my local shop said he was told the motor doesn't need these for break in any more and they are no longer included. Nothing lasts forever but this truck rocks!

bigtrucklst

I am through 2 and a half gallons. I took the washer out. Actually It just fell out with the one way bearing. the hole was shaped like an egg. Glad i took it out. It did not have much time left.

danedelman

My Feedback: (25)

I just got a LST and ran about 1/2 gallon through. I am glad I just joined because I never heard of this. I remember not using a shim or washer on my Savage rotostart and blowing one way bearing faster than ever. Will this happen when I remove the washer??

jefx

You may experience a little wear on the rotor, and possibly the conrod, but it's better than having a blown engine.

The engine was designed for a pull start, and it will only operate flawlessly with the pullstart assembly. Using the rotostart "requires" the washer, but it is a faulty design.The washer will fail due to the stresses of the engine.

Neither removing the washer or leaving it in is the perfect solution, but removing it is by far the lesser of two evils.

danedelman

My Feedback: (25)

Alright, I gave in and removed the washer. I had 1/2 gallon at least through and it seemed to be in new condition. Just a little cupping around the shaft hole. I sure hope nothing goes wrong because of this. thanks

bigtrucklst

I dont think removing the washer will hurt anything. But not removing I believe will eventually kill it.

swolrath

Hello guys , My name is sven and im from Australia and just got a LST No 7995 I pulled out my washer and would like to say it is maginetic which means it isnt aloy if is very thin but took it out anyway.. Cant wait to go down the track in the morning and do some laps...
(they are still doing the washers but in steel, maybe thay will last?)

Z Car

Thanks to Jefx for a helpful thread.

You suggested using Permatex Ultra Copper High Temp Sensor Safe Silicone Gasket Maker to seal up the engine after removal of the washer. Where do you buy this sealer? Do you discard the rubber gasket that is attached to the backplate?

BTXpress

My Feedback: (1)

Z...keep the rubber gasket. You are using the RTV to help seal against any imperfections etc from the gasket.

You can get that type of RTV from your local automotive store. It may not be "permatex" brand, but you can get it at Autozone, etc. I can't remember what brand I got, but its exactly the same.

BowDown

I'm still not convinced. I'm well into my third gallon and have had no engine problems. Sure, a few (maybe a hundred??) individuals might have experienced this inconvenience. No one really knows how many engines had suffered this supposed flaw. If it is a flaw, and is covered under warranty (equating to lost revenue) than why are they still manufacturing engines with the washer in it. This problem was first documented within the first 2,000 LSTs...what's being sold now 9,000...10,000...and still the washer is apart of the "new" engines. We all know things in this world can be blown out of proportion, maybe this is too? I do feel for those unfortunate souls that have suffered unnecessary down time, but how many (% of LST owners) have really experienced this before taking the washer out? How many are running strong with the washing not taken out?...both rhetorical questions.

I love my LST! I plan to run it, run it, and run it. And if my engine blows, I hope I’ve gone through 7, 10, or 20 gallons of fuel by then. I can legitimately play my warranty card and get a new engine. Not a bad deal in the worst case scenario. If it happens tomorrow, I still get a new engine. I could use the down time. I’m unhealthily addicted….it’s like crack…fine wine…hot chicks…can’t get enough. I don’t mean to bust on anyone’s experience, just my opinion…you know what they say, “an opinion is like an a$&hole: everyone has one and they’re all full of sh#%.” I’m just another satisfied LST owner.

jefx

That's fine. Enjoy your LST, it's a great truck.

No one's trying to convince you either way. You have options, and you've already decided the route you're going to take.

This thread is here to warn people of a common problem with the LST. This thread has also saved many people's engines. Once you are informed, then it's up to you to decide what you want to do, and you have.

Joules88

Hi all,

After all the hype about the dreaded washer I decided to strip my engine down after 5 tanks and completion of the first stage of running in using 16% Nitro.

My motor is on a car with serial 9449 and indeed the washer is still present between the Conrod/bronze sleeve and the slotted starter drive.
(i.e. located between Part No. DYN0910 and DYN0919 assembly w/o pull start (the washer is missing from the exploded diagram in manual).


On a positive note there was no apparent debris that has been mentioned by some but......

Now the negatives -

One screw holding the plate DN0942 was loose and unwound 2 turns!!

Also I was very unhappy to see one side of the washer with no adverse signs of wear but the other with a noticeable groove which I measured with a micrometer 0.22mm STD Thickness but there us approx .05~0.1mm wear already. This is factual stuff and consequently that wear and resultant debris has been through my engine.

This cannot be acceptable from a design perspective. I am a professional engineer and well placed to appraise this fault. I also cannot understand why LST are still making the engine in such a manner??

IMO I recommend those who own the LST (and who are competent) to at the very least disassemble your motor and inspect the washer for yourself. Up to you then whether to put back in.

I will try and speak with Horizon about the issue and keep all you posted.

Joules

I have some images to support ----

Joules88

Should have mentioned I hope you can see one side of the washer with minimal wear and the other with a developing groove.

Sorry about image quality but it is not easy doing close ups with my digi camera.

Joules

Joules88

A better photo showing washer wear....

RC_UK

I just removed mine todaybecause the one way was shot aswell, but soaking it in wd 40 did the trick, its working again now with no money spent


BUT Ive heard the back plate is ment to be tough to get off(ie. people stripping screws), mine wernt! they were in, but they were not as tight as i would thought or as I would like. Hmmmm are they getting a bit slack on the engine build now???

jefx

I have #633, and my starter plate and backplate screws came off without any trouble at all. In fact, my starter plate screws were a little loose.

I didn't even come close to stripping them and I was more than able to re-use them.