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Old 06-13-2008, 09:26 PM   #1
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Default Need HELP with V-Spec

Just picked up a freshly rebuilt (by O.S.) VZB V-Spec from a local guy the other night. Im getting ready to put it in my RC8 and have a couple questions that I could really use some help with.

1) Does this motor not use a return spring on the carb slide like some other motors do? And if it does...where does the spring attach to? Pictures would be great if anyone has some.

2) What are the factory needle setting on this motor? I need to break it in, and since I bought it from somebody else I have no paperwork for the motor.

Thanks in advance....Please reply quick. I'm excited to get this thing broken in!!!
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Old 06-13-2008, 10:35 PM   #2
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Mo boost, there is no throttle return on the v-spec carb.There are several ways to create your own, use of a rubberband, losi makes a nice kit, or even an oring that can be found at a plumbing store. Which ever you choose just make sure that there is just enough resistance to close your carburetor in the case of lost power or failed servo.

As for the needle settings I cant help you there but I would advise the use of a heat gun before the first few initial starts to take some stress of the connecting rod and just keep your settings on the rich side while keeping your throttle inputs very small and short little bursts. Avoid going wide open and just slowly keep leaning the motor out and at the same time introduce more throttle to the engine. You will get a lot of different answers on break in because we all have a method that works for him/her , but just be patient and take the proper precautions and you should be fine. Hope this helps.
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Old 06-13-2008, 10:45 PM   #3
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High Speed - (see pg 17 of manual) 3 turns OUT from fully closed
Metering Needle - (see pg 22 of manual) Head of screw is flush with
ball link body
Mixture Control Valve - (see pg 22 of manual) Head of screw is 1 full
turn IN from flush with carb body
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Old 06-13-2008, 10:51 PM   #4
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imaxx21 hit it on the head

My motors are around 2 1/4 out on top.... flush in the middle and 3/4 in on bottom..... I'm at 4,000ft with a 6mm restrictor

for a return..... pick up a package of hair ties, the ones I have are like 1" dia and made out of a silicone like rubber band.... a couple bucks at the store ad they'll last forever, put them around the ball link and HSN

Also - rebuilt? meaning what? P/S P/S/R
One thing I do is prime the motor everytime I start mine..... plug the exhaust on the starter box for a few seconds, that keeps the rod end of the crank from going bad as quick
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Old 06-14-2008, 12:47 AM   #5
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As I stated before I have no paperwork for the motor, because I bought the motor off of someone else.

Rebuilt as in P/S/R and new bearings.

Thanks for all the help guys!
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Old 06-14-2008, 02:23 AM   #6
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Running in the new boy on the block as posted by Jon dell in the UK he does all John Hazlewoods Motors and pit work at National level upwards so he knows his stuff.

In being asked to write about how to run-in engines, I found myself with a bit of a problem, there are quite a few different opinions on how best to do it. In the end the answer was with the Editor, he wanted to know how I did it and was there any advice I could pass on to the readers.

Over the past 3 years, I have been mechanicing for Jon Hazlewood and between us, we have had a high degree of success with our racing. One of the key aspects of our set up is to have a reliable engine. I have always believed that IC racing is about endurance and not necessarily about being the fastest. At the end of the day, an engine which does not continue to run all the way through a final is not going to win you many prizes.

Running-in an engine can effect how reliable an engine is throughout its life span. Choosing the right ingredients for your engine package will also affect the life span of the engine, but hopefully you would have chosen them by now. If not, then try to stick with the manufactures recommendations or ask other drivers at your club that are using the same engine of your choice.

When I need to run-in an engine I do try to plan ahead and not run it first time at a big race meeting. This isnít always the case and is a difficult thing to control and unfortunately I have been seen to run-in an engine the night before a big race. End result is that the engine needs to be perfect for the practice so that effective car set up can take place. The best situation is to run-in the engine before you get to the track and have that first run at a club meeting or even a practice day.

My method is a well tried and tested and learnt in the main from other racers that I have had the pleasure to have met at race tracks. Successful running-in can be made easier well before you put the car on the starter box. Removing the engine from the box I will bolt on the engine mounts, fit a flywheel that has a good knurling on its edge. This is important as the engine is going to be tight at its top dead centre (the point where the piston gets stuck in the liner) and the starter wheel will need to grip on to the flywheel in order to rotate it. The knurling can be refreshed with a triangle shaped file. Just re cut the edges into the flywheel, takes some time to do, but save money and running-in frustration.

Fit the clutch system and ensure the clutch bearings are in good condition. New exhaust gaskets/joiners, fuel pipe, and air filter should be fitted to ensure leakages donít occur and that everything is clean, free from dirt. It might be worth cleaning out the fuel filter and flushing out the fuel tank as well. Itís possible you are running-in an engine because your old engine failed for some reason. That reason could be something outside of the engine components, such as the items I have mentioned, so check them with care.

Bolt the engine into the car and set up the throttle linkages. I always set up my linkages so that the horn is north to south of the servo, and the carb is always full shut with a 1mm or gap before the servo can open the carb (see picture). Failure to do this may mean that the engine could stop when applying the brakes as the idle would fall to low as the carb fully shuts.

Yet another important issue is does the starter wheel actually turn the engine flywheel. You can check this with the starter box unplugged. Push down on the car, so that the flywheel touches the starter wheel. Check to see if the starter wheel is touching the chassis. If it does this will slow down the starter wheel and it may not transfer its energy to the flywheel. You can file the underneath of the chassis to allow for more access for the starter wheel to flywheel.

Now fully charge the starter box and the glowstart and go find a nice spot to run in your engine. With all the prep work done this is now going to be easy. Here are the bullet action points on running it in:-
ē Put a few drops of after run oil down the plug hole, just before you attempt to bump the engine. This will add lubrication and help turn it over.
ē Prime the fuel into the engine by blowing down the exhaust pressure fuel line. If you open the carb as well, carb will fill up with fuel again adding lubrication where itís needed.
ē Turn the main (top end) needle out by one full turn, this will ensure the engine will at least run rich first time.
ē Open the carb fully by moving the servo by hand. Running in using the radio ties up your hands and makes it harder.
ē Clip the glow start on and leave for 5 seconds to full warm plug.
ē Now dump the engine down onto the starter wheel. If your lucky the engine cranks, fuel pumps through and hopefully fires. If not the engine locks. This seems brutal, but you now need to take a screw driver and leaver the flywheel around from underneath the chassis.
ē On the engine firing, close the carb, but not fully. The goal is to have the carb fully open but running dead rich, the wheels should be turning but not fast, the engine tone should sound very flat, smoke and lots of oil should be coming out of the exhaust. This is achieved by now opening the carb and turning the main (top end) needle out. If you go too far and the engine is starting to stall, quickly pinch the fuel line to the carb. This will lean the engine out so you can quickly adjust the settings.
ē There is a balance between running the engine rich enough and hot enough. To be honest this balance canít be taught, but learnt by doing it.
ē Run 6 tanks through the engine on this rich setting. Before opening the tank lid to re fill, shut the carb, and quickly fill. Then slowly open the carb. You may have to pinch the fuel line again to ensure the engine does not stall.

Sometimes you will find as the fuel goes down in the tank, the engine gets leaner. This it sometimes due to air leaks in the tanks that arenít noticed during normal running. As it gets leaner, the revs will increase. Adjust the settings to keep the engine running rich at all times.

After 6 tanks, the initial running in is complete. Now wind in the main (top end) needle back to around where it was out of the box. Tuning is another issue, but for now run the car up and down a tarmac strip or dry track. Different engines may require more than one tank to fully run in, but for the engines I use one extra tank on a flat bit of ground is enough. The car should accelerate smoothly with plenty of smoke from the exhaust. Monitor the engine temperature, making sure that itís not too hot.

To finish off I would run the engine for a race meeting with a rich setting. This is not so rich it doesnít perform, but rich enough so that it does not run hot. After using the engine always add after run oil down the plug hole to avoid rusting of internal parts.
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Old 06-14-2008, 09:42 AM   #7
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Add this step: Preheat the engine with a heat gun before starting every time for the first gallon.
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Old 06-14-2008, 01:14 PM   #8
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Thanks guys!
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Old 07-12-2008, 05:49 AM   #9
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Originally Posted by HighPowerHobby View Post
Add this step: Preheat the engine with a heat gun before starting every time for the first gallon.
+1 Which any new tight motor will more than likely need.
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Old 07-12-2008, 09:47 AM   #10
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Although it's not terribly helpful, here's the manual:


There are very few legitimate products that don't have an online manual on the manufacturer's website. I have the V-Spec too - enjoy that beast!
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