New engine pinch... even OFNA truggy box is smoking
02-13-2009, 06:45 PM
#16
I'm surpised no one has mentioned this yet. Go includes an extra head shim inside the box purposely for break in. Install that, and use all the other suggestions others have had. 
02-13-2009, 06:59 PM
#17
Heat 'er up....
Burned a groove in the wheel before I was able to get the heat gun. Once I heated her up, it would turn over with no problems. After 2 or 3 tanks, you shouldn't have to heat anymore....
02-13-2009, 07:06 PM
#18
One of the best investments I have bought was a engine break in stand. I have broken in some really tight engines with ease.
On the other hand, do as the rest are saying. Get a heat gun and heat that thing. Put it on the box and keep it running.
On the other hand, do as the rest are saying. Get a heat gun and heat that thing. Put it on the box and keep it running.
02-13-2009, 07:38 PM
#19
Mark,
Heat guns are fine and all.. but they produce localized heat and even when you move the gun all around the heat doesn't get to penetrate deep into the block. I'd suggest putting a bit of oil in the block & in the combustion chamber & popping the engine in an oven @350 for 10 min. Get your Mom's permission first 'cause it's going to make the oven stink like hell for the next week
. When the whole engine is good and hot, rock the piston back & forth at TDC. When the engine begins to cool drip more oil in the plug hole & keep rocking the crank. If the engine is still super tight, repeat & reheat. The bind from a really tight pinch hurts the pins and stresses the rod unnecessarily (sp?
)
Side note: the manufacturer is supposed to carefully match pistons and sleeves during the assembly process. I've come across mis-matched P/S on new engines in the past. The only option in that case is a new P/S. But before you go there get a second opinion.
Heat guns are fine and all.. but they produce localized heat and even when you move the gun all around the heat doesn't get to penetrate deep into the block. I'd suggest putting a bit of oil in the block & in the combustion chamber & popping the engine in an oven @350 for 10 min. Get your Mom's permission first 'cause it's going to make the oven stink like hell for the next week
. When the whole engine is good and hot, rock the piston back & forth at TDC. When the engine begins to cool drip more oil in the plug hole & keep rocking the crank. If the engine is still super tight, repeat & reheat. The bind from a really tight pinch hurts the pins and stresses the rod unnecessarily (sp?)Side note: the manufacturer is supposed to carefully match pistons and sleeves during the assembly process. I've come across mis-matched P/S on new engines in the past. The only option in that case is a new P/S. But before you go there get a second opinion.
02-13-2009, 08:18 PM
#20
I took my clutch bell off. I dropped some oil in the plug hole and I'm rotating the shaft with the 5/16" nut. I'm just hoping it will loosen enough that my starter box will be able to turn it.
Basically, it's 10pm on a Friday night and I'm sitting on the couch, fondling my engine.
Chunk T, I assume I'll need to remove the carb before baking the engine at 350? I have powder-coating ovens that I can use instead of the kitchen one.
Basically, it's 10pm on a Friday night and I'm sitting on the couch, fondling my engine.
Chunk T, I assume I'll need to remove the carb before baking the engine at 350? I have powder-coating ovens that I can use instead of the kitchen one.
02-13-2009, 09:30 PM
#22
I took my clutch bell off. I dropped some oil in the plug hole and I'm rotating the shaft with the 5/16" nut. I'm just hoping it will loosen enough that my starter box will be able to turn it.
Basically, it's 10pm on a Friday night and I'm sitting on the couch, fondling my engine.
Chunk T, I assume I'll need to remove the carb before baking the engine at 350? I have powder-coating ovens that I can use instead of the kitchen one.
Basically, it's 10pm on a Friday night and I'm sitting on the couch, fondling my engine.
Chunk T, I assume I'll need to remove the carb before baking the engine at 350? I have powder-coating ovens that I can use instead of the kitchen one.
I usually watch a movie or my kids playing video games as I try to lap a piston by hand.
Like 22Racer suggests, once you can get the engine to run on it's own use a hot plug and a fat needle to keep everything wet and running. The key to getting a good lapped fit between the P&S is to heat cycle the engine. Since you will run a really rich needle during break-in, I recommend getting up in the mid 200's. The rich needle is going to hold the sleeve temp down, so make sure you cover some cooling fins & monitor the temp. IMO I also recommend breaking the engine in under load (drive the car). Unloaded the engine will naturally run a bit leaner.
02-14-2009, 06:09 AM
#23
Breakin is simple once you know why your doing it.
Your just lapping the piston and sleeve smooth and fitting them to each other so that they are the same size and seal well.
Problem is metal changes size as it changes temp.
If the piston and sleeve are perfectly fitted and sealed at 230 degrees then they will not seal at 130.
If you breakin too cold then you just set the fit and seal at too low a temp and it'll lose compression some when its hot.
It is key to breakin near race temps 212-230 AFTER first running the engine as slow (idle) as u can for 125cc at factory setting to lap the piston.
Deos anyone know why Os, Werks, and Go-tech are so much harder to turn over when new compared to Rb, Novaarossi, GRP.
Your just lapping the piston and sleeve smooth and fitting them to each other so that they are the same size and seal well.
Problem is metal changes size as it changes temp.
If the piston and sleeve are perfectly fitted and sealed at 230 degrees then they will not seal at 130.
If you breakin too cold then you just set the fit and seal at too low a temp and it'll lose compression some when its hot.
It is key to breakin near race temps 212-230 AFTER first running the engine as slow (idle) as u can for 125cc at factory setting to lap the piston.
Deos anyone know why Os, Werks, and Go-tech are so much harder to turn over when new compared to Rb, Novaarossi, GRP.
02-14-2009, 07:08 AM
#24
Breakin is simple once you know why your doing it.
Your just lapping the piston and sleeve smooth and fitting them to each other so that they are the same size and seal well.
Problem is metal changes size as it changes temp.
If the piston and sleeve are perfectly fitted and sealed at 230 degrees then they will not seal at 130.
If you breakin too cold then you just set the fit and seal at too low a temp and it'll lose compression some when its hot.
It is key to breakin near race temps 212-230 AFTER first running the engine as slow (idle) as u can for 125cc at factory setting to lap the piston.
Deos anyone know why Os, Werks, and Go-tech are so much harder to turn over when new compared to Rb, Novaarossi, GRP.
Your just lapping the piston and sleeve smooth and fitting them to each other so that they are the same size and seal well.
Problem is metal changes size as it changes temp.
If the piston and sleeve are perfectly fitted and sealed at 230 degrees then they will not seal at 130.
If you breakin too cold then you just set the fit and seal at too low a temp and it'll lose compression some when its hot.
It is key to breakin near race temps 212-230 AFTER first running the engine as slow (idle) as u can for 125cc at factory setting to lap the piston.
Deos anyone know why Os, Werks, and Go-tech are so much harder to turn over when new compared to Rb, Novaarossi, GRP.
About Go-Tech being harder to turn over when new, I read something about that when searching furiously for answers to my problem. The president of Go-Tech said it was intentional, that they believe more pinch when new makes for a longer-lasting engine. I'm sorry I can't provide a link... I just kinda stumbled across it last night.
02-14-2009, 07:25 AM
#25
Update:
Not much of an update, actually. I've continued to put oil in the engine and I'm still turning the shaft with the 5/16" nut driver. It seems a little easier to turn, but I don't know if it will turn over on the starter box yet. I wish I was able to bolt the engine down to something and put a prop on it so that I could start it that way.
I'm going to take my new truggy to the track today anyway. Someone up there will be able to help get it started for the first time. There's a proper heat gun / paint stripper at the track I can use.
Once I get it started, I'll use the suggestions in this thread to break it in properly.
Not much of an update, actually. I've continued to put oil in the engine and I'm still turning the shaft with the 5/16" nut driver. It seems a little easier to turn, but I don't know if it will turn over on the starter box yet. I wish I was able to bolt the engine down to something and put a prop on it so that I could start it that way.
I'm going to take my new truggy to the track today anyway. Someone up there will be able to help get it started for the first time. There's a proper heat gun / paint stripper at the track I can use.
Once I get it started, I'll use the suggestions in this thread to break it in properly.
02-14-2009, 08:39 AM
#26
Tech Regular
If its cold outside, wrap the head in tin foil, will help keep the heat in.
I'm currently running a novarossi in (very very tight, would not turn over unless heated), been very difficult to keep the temps between 210-230. Had to keep the heat gun on lightly, now its running around with load on its been keeping temps, whilst still being very rich (my garage floor is covered in oil).
I'm surprised your having trouble with your ofna box, its one of the strongest boxes around. I'd check the contacts on the switch, as they have melted on quite a few of my mates boxes. Its also worth re-wiring the box as well, the tamiya conectors melt after a while.
I'm currently running a novarossi in (very very tight, would not turn over unless heated), been very difficult to keep the temps between 210-230. Had to keep the heat gun on lightly, now its running around with load on its been keeping temps, whilst still being very rich (my garage floor is covered in oil).
I'm surprised your having trouble with your ofna box, its one of the strongest boxes around. I'd check the contacts on the switch, as they have melted on quite a few of my mates boxes. Its also worth re-wiring the box as well, the tamiya conectors melt after a while.
02-14-2009, 08:51 AM
#27
If its cold outside, wrap the head in tin foil, will help keep the heat in.
I'm currently running a novarossi in (very very tight, would not turn over unless heated), been very difficult to keep the temps between 210-230. Had to keep the heat gun on lightly, now its running around with load on its been keeping temps, whilst still being very rich (my garage floor is covered in oil).
I'm surprised your having trouble with your ofna box, its one of the strongest boxes around. I'd check the contacts on the switch, as they have melted on quite a few of my mates boxes. Its also worth re-wiring the box as well, the tamiya conectors melt after a while.
I'm currently running a novarossi in (very very tight, would not turn over unless heated), been very difficult to keep the temps between 210-230. Had to keep the heat gun on lightly, now its running around with load on its been keeping temps, whilst still being very rich (my garage floor is covered in oil).
I'm surprised your having trouble with your ofna box, its one of the strongest boxes around. I'd check the contacts on the switch, as they have melted on quite a few of my mates boxes. Its also worth re-wiring the box as well, the tamiya conectors melt after a while.
The truggy box is working good and it's very strong, it's just the pinch is too tight and the rubber wheel is smoking against the flywheel. The truggy box itself is every bit as strong as I expected it would be (it's new).
02-14-2009, 09:03 AM
#28
Tech Regular
Make sure the wheel hasn't got any oil on it, same goes for the flywheel.
I destroyed a fly wheel on the last RB I broke in, it was so tight it was unreal. I didn't lose its mechanical pinch till the 3rd gallon. Then it went for another 4 gallons after that before the gudgeon clip came out and killed the liner and piston.
I destroyed a fly wheel on the last RB I broke in, it was so tight it was unreal. I didn't lose its mechanical pinch till the 3rd gallon. Then it went for another 4 gallons after that before the gudgeon clip came out and killed the liner and piston.
02-14-2009, 05:47 PM
#29
Tech Initiate
also make sure te starter wheel isnt hitting the chassis and scrubing speed... 1 more thing, let the starter box "spin" up before you push it the rest of the way down to make contact with the flywheel.
Other than that, use a heat gun like these guys are saying, and make sure your glow igniter is strong..... so when it does get spinning it'll start. bump the idle screw up about a turn, the first tank is always the hardest
My GO EB Mod 5 port has about gallon on it and I still cant turn it by hand when cold..... these things have pinch forever it seems like.
Other than that, use a heat gun like these guys are saying, and make sure your glow igniter is strong..... so when it does get spinning it'll start. bump the idle screw up about a turn, the first tank is always the hardest
My GO EB Mod 5 port has about gallon on it and I still cant turn it by hand when cold..... these things have pinch forever it seems like.
02-14-2009, 09:25 PM
#30
Update #2:
I took it to the track and borrowed the shop's heat gun. It eventually started!
I let it idle two tanks and put the heat gun to it to keep it around 200f, while running it very rich. Then I ran it about 1/2 tank slowly around the track in my new 8ight-T, spewing smoke. It was running 165f, so I put some foil on it. Then I leaned it just a bit, still smoking the place up and burning my eyes and nose with fumes, and ran it slow again.
It's got about 3 tanks on it now. I'm going to take it to the track again tomorrow and break it in some more.
I'm thrilled as a pig in poo that it started up. Even running very rich, I can tell there's a pooload of power waiting to come out.
I took it to the track and borrowed the shop's heat gun. It eventually started!
I let it idle two tanks and put the heat gun to it to keep it around 200f, while running it very rich. Then I ran it about 1/2 tank slowly around the track in my new 8ight-T, spewing smoke. It was running 165f, so I put some foil on it. Then I leaned it just a bit, still smoking the place up and burning my eyes and nose with fumes, and ran it slow again.
It's got about 3 tanks on it now. I'm going to take it to the track again tomorrow and break it in some more.
I'm thrilled as a pig in poo that it started up. Even running very rich, I can tell there's a pooload of power waiting to come out.