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12-08-2019, 11:08 AM #1
- Join Date
- Aug 2019
- Rep Power
HELP! Hyper 7 TQ Engine Problems During Break-in
Sorry for the long post that's coming up.
Haven't played with Nitro care for at least 10 years and just bought a brand new Hyper 7 TQ Buggy with the Hyper 21 3-port engine for my son to try and introduce him to the hobby. It's been a nightmare trying to start the engine to do the break-in process. My son hasn't been happy about it and I'm worried it's going to put him off the hobby even before he's started.
Was going through the break-in process of idling the engine for 3 tanks and then 2 tanks of easy driving, as per the manual that came with the car. Anyway, before even getting the engine started on the first tank, we broke the pull start, it wouldn't recoil. It broke because of the hard pulls, especially with the tight pinch of the piston and sleeve. Took the pull start off the engine to have a look and the spring popped out and it was a nightmare trying to put it back in. So decided to remove the spring and the cord winder and just put the cover back onto the engine and plug up the hole where the cord goes through. I had a starter box, so decided to use that to start the car. Tried numerous times to start the engine, but it wouldn't start. There would be times when the piston would get to TDC and get stuck due to the tight pinch of the new engine, so I would turn the flywheel by using a screwdriver and prying it from the bottom to make it turn as it was too tight to just use my fingers. Of course, each time this happened, it would slightly damage the flywheel. the tightness was there even when I removed the glow plug. Anyway, did this a few times and eventually the engine started and we left it idling for the full tank.
Once the tank was almost empty, we stopped the eninge and left it to cool down for 5 minutes, making sure the piston was at BDC and "loose". Go to start it again, same thing happens. It would crank a little and then get stuck at TDC and have to pry the flywheel to loosen it and then tried starting it on the box again. Did this again and again and it would get stuck again and again. During my attempts to start the engine, I would remove the glow plug to release the compression, heat up the engine with a heat gun and try to crank the engine, but it would do the same thing of getting stuck at TDC. Even running the engine for one tank, it didn't seem like the tightness had reduced. So kept prying the flywheel to loosen it, then trying to start it on the box. Eventually after about an hour of trying, it finally started and we idled it for the second tank.
Time for third tank and what do you know, the same thing happens. Spent another hour doing what we have been doing just to try and crank the engine and start it. While during this time with all the prying of the flywheel, most of the small teeth on the flywheel have broken off from the the force required to turn it using the screwdriver. Eventually it started and I'm thinking surley it will be all nice and loose by now after three tanks, so I can just turn it with my fingers. NOPE!
Going for the 4th tank and again the same issues. This time it seemed like the tightness is even worse! with all the prying, the flywheel pretty was much shot and doesn't have any teeth left in the areas that corresponds to the piston's TDC. I even broke two screwdrivers trying to pry it and tunr it. I removed the engine from the car to turn the flywheel with my hand. It required alot of force to turn it and eventually it got loose, so I'm thinking it should be ok now. Put it back onto the car and try to start it and it happens again and the piston gets stuck at TDC with no way of being able to turn the flywheel without taking it off the car again. At this point I'm p1$$ed off and gave up.
Has anyone had this problem before and if so, how did you sort it out? I'm really stumped on why the pinch is so tight. I know new engines are tight, but not this tight, especially after 3 full tanks of idling. I've given up on trying to sort it out and pretty much thinking it's a $500 dud that I bought. The unfortunate thing is my son has waited so long to play with it and his disappointment really shows. I'm going to take it back to the hobby shop I bought it from and see if they can help. I might need to get the flywheel changed, because it looks terrible. Knowing my luck, they will say the engine is stuffed and not covered under warranty!