razordave

I bought this truck for $190 I think I got a decent deal.


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Seller test drove for me, not very long but I was anxious to get it home so as long as it somewhat functioned I was comfortable with the price.

Got it home, put all fresh batteries in and buzzed it around a little bit. It doesn't really seem right, like it's sticking in second gear.

Tear the transmission down and it's pretty dirty with what seems to be worn plastic gear residue. I clean everything with rubbing alcohol on qtips and proceed to reassemble.

Remove the clutch bell and clean flywheel/clutch shoes with small brass wire brush. Scraped the worn shoe residue from the clutch bell. The residue was a small ring in the gap where the spring goes, making it slightly tough to remove the clutchbell.

So reassembled, changed the broken upper a arm and proceed to take it out for a spin.

Truck ran much better until it warmed. I did some reading on tuning the carb and it seems like factory specs are way too rich..

I'm getting a little worried now since the previous owner didn't seem to know how to do anything but run it..

I read that if you don't break them in properly, you lose compression once it warms.

Any advice on troubleshooting/repair/tuning or opinions on what my problems really are?

razordave

My next plan of attack is to pull the carb and clean it thoroughly. I will use nitro fuel, maybe some rubbing alcohol.

After it's back on, I'll set everything at factory settings again and give it a try.

Also, anywhere I should check for compression leaks?

westoakmech

Those tires are pretty massive. What is the gearing in it. If it was not geared down, you will probably have problems with it due to those large tires. If the engine runs until it gets warm, dies, then will not restart until it has cooled down, then it is probably toast. You can check around the base of the cooling head for a compression leak, it will usually show some signs.

razordave

The jumbo kongs are 8.5 inches tall. I guess the stockers are 5.25 in. I bought a 65 and a 68 tooth spur gear at the lhs and ordered a 14 tooth clutch bell to help in the gearing offset.

For anyone looking to gear lower.. the 68 tooth will not fit with the 68 tooth spur. Not only does the stock clutch bell gear hit the throttle post, but you also don't have enough adjustment on the motor mount slots in the chassis.

The 14 tooth should remedy the huge tires as far as gearing goes. We'll see how the steering holds up..

I was really surprised how the factory brakes do with the jumbo kongs.. but I've not had stock tires to compare the performance.

I ended up not having a wrench to fit the carb screw nut.

I pulled the head, all looks good there, I'm going to give it a thorough cleaning and reinstall, probably flip the copper head gasket over.

The carb definitely needs cleaned and I think the LSN needs adjusted. I however also need a smaller flathead screwdriver.

I am almost certain that my running issues are in the carb, the fuel lines seem pretty new and the tank seemed tight on a quick check.

razordave

I still haven't purchased the wrench/socket I need to pull the carb from the engine :/ I did however pull the HSN housing from the carb and attempt to clean that way..

I also pulled the piston and sleeve, they seem to be pretty loose at this point and will most likely require replacement. I decided now would be a good time to do the sleeve mods and put it all back together freshly cleaned to see if it runs.

It's dark so I can't quite test it but I'm excited as upon re-assembly, the engine seems to have some more compression. I'm sure once it heats it could lose that but only the test drive will tell for sure.

razordave

In case anyone has been following this.. It finally runs. I get about 5 minutes in between stalls. I took it pretty easy for the first 2 tanks this morning since I did have the piston out of the sleeve.

I suspect that once it's re- broken in, it'll run a good bit better. I have a clutchbell on the way with less teeth and then I can put the 68 tooth spur on also.

The truck does pretty well once it's rolling, but with the jumbo kongs it really needs some lower gears to be able to launch.

I do somewhat expect crawling capabilities with the 14 tooth CB and 68 spur since the truck started with 22 or 24 (haven't counted yet) CB and 58 spur..

razordave

beerrraaaap! lol I can't wait to get home and play with it Bawwaaaah zing

Ordered new clutch shoes and spring to go with the new clutchbell and exhaust coupler/diverter combo

Anyone have experience running paddles backwards? I read to do so on the front axle to help steering and to float, but how about running front and rear backwards to keep from killing the tread on the asphalt?

The truck came with what looks to be proline slingshots but I haven't looked at them much. I don't live very near to the beach but when I have some time I'd like to take it with me.

razordave

Got my first 15 minute run without stall in. I'm not sure if it died because I did a couple 5/8 throttle passes because it's way rich or if it's a low idle or what yet but I was thinking about porting the crank.

I've seen a few great examples and I think I'm ready for it.

The gearing is still 22 to 65 until Wednesday but I'd say it did pretty good. It carries one front wheel floored from a standstill. I really shouldn't be doing that since it's basically still in a break in period of sorts.. but hey, it's a toy anyway.

razordave

DANG so I tore the engine apart again to do some porting on the crank and found a puked crank bearing.

Anywho, ordered up a crankcase with bearings and crank on eBay for 18 USD shipped! not a bad deal at all I'd have to say.

I'm going to order a complete new engine next time I get paid and possibly a piston and sleeve.

Does anyone have experience with Davis Diesel Conversions? I was eyeing that crank until I saw RBmods also makes one double bushed.

dtslmberne

I bought a 65 and a 68 tooth spur gear at the lhs and ordered a 14 tooth clutch bell to help in the gearing offset.

razordave

My truck came with a 58 tooth. I don't know what the original is but..

The 68 tooth didn't allow the clutchbell to clear the throttle post thing but I think the 14 tooth will solve that problem.

razordave

Nothing to post really, I've been porting and polishing my crank since there's a spare coming with the crankcase. I figure if I mess it up oh well lol

Sorry for the crappy cell phone pix, I really need to buy a decent camera. The lighting is from the computer monitor, seems the only way I could get any kind of detail.








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It ended up looking like mickey mouse ?! lol

The sleeve looks a little better but I'm thinking this will really wake my truck up.

Anyone have a line on a bigger carb?

razordave

Got the crankcase in today, reassembled everything and no fire. It is not warm out and it's possible the battery in my glow ignitor is bad so I'll wake til the morning and preheat the engine then try with a fresh battery :/

Hoping there's enough compression to run..

Also the new crank didn't want to come out of the bearings so I left it in there.. My thought was that after a couple heat cycles it should be a little more agreeable.

razordave

She runs.. I tore it apart a couple more times just to eventually find a bad glow plug smh