csa

Hi.

My pull start (on a gst) has stopped turning over the engine consistantly, occasionally it works but thats not really good enough to start it. The manual is a bit lapse in this area so I'm not really sure what to look for. Has anyone else experienced this got some wise words?

Craig.

The Real Dogman

Hey Craig,, How do you like your clutchbell tool??

Sounds like your oneway bearing on the back of your engine has failed or is failing. Its an easy repair if you follow my [link=http://www.cenracing.com/downloads/TRonewaywriteup.doc]My Instructions Found At CEN's Official Download Site, Here!!![/link]

If you pull on the pull start and it recoils but does not engage the motor to turn it over it is definitely the one way. Now since you say it engages inconsistantly the I will guarrantee your one way is shot. Just follow my instructions and you will be set!!

JeffyB

Dogman is right he replies to so many of these threads and he's always nice about what will soon become common knowledge to anyone involved in nitro. Follow his instructions and save some money or buy a new owb.

csa

Hi Dogman. Yeah the clutch bell tool is a life saver.

A few weekends ago I put the center lock in and by the time I reassembled everything, I found that my gears were too poor and that they would not mesh smoothly when turned due to the wear. I pulled them off - get a load of the in the picture - it seems my gears (from factory) weren't really meshing together very much at all, i.e. too far apart? I decided that I'd put new ones on - after a few attempts, into the oven it went (wish I'd done that first) - It took another couple of disassembling & reassembling to get good alignment.

Craig.

The Real Dogman

Glad to hear the the bellbuddy worked out well for you..

Yeah, thats why it's always a good idea to go thru a new vehicle to check everything to be sure it was assembled properly, before you run it in(break it in). Thats one of the most misunderstood concepts about Ready To Run rc kits. The factories assemble these trucks as a means of bringing in more people who before would not buy one because of the pain in the A__ it is having to buy other components to get it to run. So the factory assembles it, rather quickly and with unskilled labor, so things get missed and misassembled. Some manufacturers do try to warn the buyers to check all screws and alignments before run in. The problem is there is usually just a single paragraph in the manual about this important step, so it gets missed very often!! Well these people get very disappointed or downright upset when something fails or falls off the first time they run the vehicle..thinking the manufacturer says it ready to run, then think it is a defect. But the concept of ready to run only means they are providing you with all of the equipement and parts to get running. The engine, radio and servos ect.. Back in the day when you bought a kit you got just the kit. You had to assemble the rolling chassis, then buy a motor (weather it was electric or nitro) a radio and servos. Some kits you even had to buy the tires and bodies separate. So fast forward to today and now you have all of the parts you need to get running. I just wish the manufacturers would be a bit more vocal about this important concept. I personally intend to attempt to bring this simple oversight to light..

Now there are a few such as yourself who have grasped the idea that these vehicles will and do fail, so its just apart of the hobby. Thats great!! It makes my job easier to explain the concept of ready to run and what it truely means.. But you will need to understand that the settings and meshing is NOT set perfect from the factory and WE the hobbyist needs to be vigialant and take the extra time to be sure all is well and adjusted and aligned.


Anyway, enough of the lecture, I hope just 1 more person learns something from my rant.


BTW good job on your repair!!!

And most of all Have fun!!!

EDIT ADD:Thank you for the praises JeffyB, just one "Hobbyist Helping Another Hobbyist"

.46NitroAddict

Hey Craig,

If you use TRD's method to replace your one way, you may find this [link=http://www.wattsuprc.com.au/product_detail.asp?pid=BearingHF0612]Aussie Bearing Source [/link], useful.

I can't claim credit for this find - I think that belongs to MonaroMan, if my memory serves me correctly!

Regards, .46NitroAddict [>:]

csa

.46 - Amazing. This place is in the suburb I grew up in.

Dogman - Thanks again for the wise words. This being my first RC anything (let alone nitro powered), I pretty much expected that wear and tear would occur, and it's no wonder with the power of this little engine. If anyone was expecting a smooth ride out of the box then they need their head checked.

However, I would have never thought to check how close these gears mesh. There are instructions in the manual which talks about alignment and I do remember that I examined it and thought yes it looks good to me, as a novice with no clue. And even if I did attempt to align it better, I probably would have stripped the engine screws attempting to undo them. It was only from one forum I learn to heat these to release the lock-tight, which btw I tried the soldering iron, maybe not powerful enough as it didn't do jack. A heat gun is the only way imo.

Unfortunately, the novice does not know what's normal until it's too late!

Rebuilding was time consuming but fun. Although I did get a little frustrated with the swing arm on the front where you need to line up the bolt and screw the pin into it on the car end, not so easy to hold the bolt straight! But I got a lot of practice as I forgot to put the dog bone in first time, second time somehow the shock was jammed into a position forcing me to unscrew it and do it 3 times before getting it right - I must have been rather tired by this point to be making such mistakes. Oh well never mind, with practice comes experience they say.

Anyway, on a slightly different matter. I noticed another odd thing after reassembling. My 2nd gear clutch bell rubs its edge against the (I think) rear break shaft!? At closer inspection, it appears to be about 1mm gap (I didn't notice what it was before disassembling) but figured its hard to get this wrong as nothing here is adjustable. Nevertheless, under the forces the truck exerts on its parts they have come together (see pic).

Craig.

nomobux

My Feedback: (4)

If Dogmans diagnosis doesn't do the job ( OW ), then pull the back plate and check the small pin and spring in the crankshaft. A fairly common prob.

The Real Dogman

Well Craig you are very right, the novice does have a harder time with what would be considered correct, but if the novice knows up front that there will be parts to replace and issues that will arise due to the lack of experience, then the novice will have a better chance at happiness. Big difference in customer satisaction.

Now, I had the very same problem on my Nemesis, I believe when this beast is at speed and you slam on the brakes, the rotational force of the rotors on the metal brake pads and cage is so strong it is actually causing the silicone bushings and aluminum shaft to flex to such a degree, that the shaft is making contact on the 2nd shift clutch housing. If you check my gallery you will see I actually removed the rear brakes, and found that my brakes still work great!! But that requires the center diff to be locked. I also had a custom Brake Cam bracket made with a flanged bearing to ease the function of the front brake cam, since it is the only brakes to stop this heavy beast!! I have extras for sale if anyone else is interested in this mod..
I dont really see this being a big issue for the average Joe bashing around or the average club racer, but the avid racer or pro racer could benefit from this mod, however most racers seem to leave the center diff unlocked so this mod wont work for them.

Anyway a couple pics for reference and fun!!

dustin7837

My Feedback: (1)

TRD:

LOL @ that Jack! undefinedundefined

Perfect size for the nemesis eh?

What was it actually for?

The Real Dogman

Hey Dustin,

I love those Floorjacks. They were intended for display but it actually will lift approx 35lb and seems to be the perfect size for the Genesis series trucks.

I got them @ Sears for about $25 each.

csa

Dogman - Very interesting. I notice a couple of things, the exhaust coupling - mine has crept apart here and I push it together every now and again. I have on order a new gasket for the exhaust header as the current one appears squashed and lopsided (see pic) - it may not be working correctly. Adjusting the high speed (1 turn out) makes little difference to temp and I often read in the 240-260 range with one of those blue duratek IR gauges. High speed needle is almost level. The manual says around 220-240 is normal, but also included is a smaller "guide" and in the back they list the 7.7 engine as 240-260 as normal - ok, which is it?

Funny you should mention the brakes actually, you're right tho, you only need one set of brakes to stop this monster - it seems (see pic) during my last tank at the park I lost the front brake!! Now I'm quite baffled by that, isn't the eye pin screwed in? Therefore can't unwind when attached to the shaft - perhaps it broke. Oh well, www.ebay....

Craig.

The Real Dogman

Not sure but it looks like your gasket is sealing tho, unless you've cleaned it.

Thats why I didn't like the screw to mount the return on the same screw which hold the front brake eyelet. I saw a potential to loosen over time so I moved my mount dount to the Custom brake cam mount.

.46NitroAddict

Hey Criag,

I too was chasing temp problems 18 months ago, The higher one is the new operating max. This link [link=http://www.cenracing.com/downloads/Engine%20Doc%20NX76.doc]NX-76 [/link] is the latest from CEN Racings web site, & would also apply to the GST. Probably just didn't get update in the manual.
After talking to Ari Balka ( [link=http://www.hobbyx.com/]HEI [/link] - Australia's Official CEN Racing Importers / Distributors ), about my temp problems he recommended using their Boost Race Fuel. I have since solved all my temp problems using it, & am currently using 20% Nitro. I have also used it in 25%. Not sure what fuel U are using, if not this, give it a try - It works!
Having said all that, I usually run mine around 220-240. (now that I am using this fuel

Kind Regards, .46NitroAddict [>:]

csa

Ok, you got me, I do keep things clean (with paint brush). You may be right about the gasket and maybe it's not overheating. Maybe <=260 is ok. What are the signs of overheating I should be looking for, stalling "at speed"?

Yes. Reading your post, it it's all clear now! I do recall the eye lever rotating by hand and I dismissed it as a problem thinking it was screwed in rather than held in by the top screw, as you've just pointed out. Bummer. Perhaps some lock-tight will help?

Craig.

csa

.46 - I'm using glo-max cb 20% (20% is highest LHS sells) - I wouldn't want more than 20%, less % = more oil = cooler right?

Craig.

.46NitroAddict

Hey csa,

No. Oil content & Nitro % are 2 Different variables. The thing that changes is the amount of Methanol.

I actually found that the highter nitro (25%) made mine run cooler, but went back to 20% to see if I could get it to run at the correct temp on this fuel (started on 25% cause thats all they had in stock at LHS at the time).
It runs fine, on both. (I used to use Premium Blend - but ran too hot - Diferent fuel manufacture).

Boost Race fuel has 15% (or 16%0 - can't remember which) Oil content, regardless of Nitro%. (I think it is 5% caster, & 10% synth).

If you want to chat, drop me a "PM" I'm on messanger Live.

Regards, .46NitroAddict [>:]

csa

Sent a pm.

csa

Dogman, what is the thing on the tube between the exhaust & fuel tank?

Craig.

The Real Dogman

Craig,

That "thing" is an Ofna fuel filter w/primer bulb(check valve). It is a solution to half tank lean condition that the genesis series trucks suffered from. It was a very common problem that requires as simple fix..

[link=http://www.rcuniverse.com/forum/m_4462148/tm.htm]You can read the entire thread here!![/link]


happy reading..

csa

Dogman, I'm just surprised given there is no fuel in that line to filter or is it two part (I see something else on your real fuel line)? Does that mean you don't need to burn you thumb on the exhaust trying to prime a hot engine? :P

Craig.

The Real Dogman

Craig,

no it does not function as a filter at all nor a primer. It only functions as a check valve, not allowing pressure back out of the tank when you let of the throttle. The intention is to keep consistant pressure in the tank when the tank get to half full it wont lean out the engine... read the thread it will explain all..