paulfitipauldi

Thanks for the tip,, that will not look pretty good, but that can cost you the race ,, I was running in first position, after I visit the board at the end of the straight, nothing was wrong with the car but the engine couldn't spit out all his power, the bend in the stinger cost me lost some positions back until I decide to retire the car from the race,, I can't drive a car , that just damm slow

InitialD

Yes, the pipe will not have the looks anymore. That is why I took the picture without that epoxy thing behind the stinger. I took the picture because I can then look back and remember how it first look like in pristine condition

bt

thanks for the reply InitialD

markp27

Amazing isn't it! You get yourself a stock of spare bits and then go a break one of the few parts you don't have!

It was my own fault: I was pretty keen to get to the track on Sunday and didn't check my setup too carefully. I thought I'd checked the tweak was ok, but as soon as I tried to break on the circuit, the car would try and spin.
This meant I couldn't break as much as I would have liked to and caused me at one point to roll the car. It didn't seem to bad, but when I checked the car, the rollover hoop had broken right where it goes into the aluminium brace

Oh well, send of another order for some more parts

The driving is getting better, I'm really able to enjoy myself on the circuit now, and that's the main thing.

Cheers, Mark.

InitialD

Glad to know despite all that has happened, you still enjoy driving

Yup, the rollover bar is the only thing shitty about the 705 I think somehow or another, everyone breaks that and exactly where you have decribed.

When you can't get the part, you improvise... In this case, you get a better part than the one for 705.

If you can get a 950 or an MRX-3 rollover bar, then that will be great. I use the MRX-3 rollover bar myself. Just think of it... If it can withstand the impact and speed of the 1/8th scale with an open and exposed Lola type shell, the rollover bar should be good for the 1/10 scale I prefer the MRX-3 rollover bar because the bendings are about the same as the original. You need to cut it shorter and perhaps bend the rollover bar forward a little to make the height lower.

Mind still holds up from day one. Well, I notice that some Holland team drivers do not use the rollover bar at all on their 705. Still OK I guess. Just that you need to use the bodyshell at all times...

markp27

Thanks for the tip!

Yeah, still enjoying the driving :-) Only frustrating that I never get to have a long run due to some problem or other - just been bad luck, nothing to do with the car.

After how many litres of fuel should I service my engine - I've no idea how many hours it has run (not that many), but I know I've used about 4 litres of fuel.

Cheers, Mark.

InitialD

I make a habit of opening up the top of the button head / heatsink to inspect the top of the piston head to see if there are any pitting after every weekend run. After about a gallon or so fuel, I take the backplate out and check the conrod bushing where the crankshaft is connected for any signs of wear and play. Check also for any rust.

I suggest that if you're gonna open the engine in and out many times, do like what I did. I changed the pathetic screws of the heatsink to allen type cap screws. It's M3 type screws and I use a 2.5 mm allen to lock and open up the screws without problem or fear of stripping the screw head !!

I do the same also for the backplate.

markp27

Are the backplate screws also M3 - do you know what length they are? Thats a good tip!

I started to get my mixture problem sorted out - althought the bottom end is a bit rich now. In the NovaMega manual, it says to open the throttle for 2-3 seconds and the release it. When I release the throttle the revs continue to fall for about 4 seconds - according to the manual this means that my low end mixture is too rich.

I don't have any misfiring any more after rolling though a corner.

Cheers, Mark.

InitialD

Can't remember off my head... But I think it's either M1.5 or M2. I know for a fact that I use a 2 mm allen to tighten those screws at the backplate. I'll go back and check. Heheh, will post a pic of it if you want

What you could do is bring a sample of the screws you need to a nearby hardware store. I use to buy quite a lot of these screws, especially the ones used on the 705. Handy to have extras around. Cheaper that way than going back to Serpent for these screws. I also replaced the Phillips engine mounting screws below the chassis to M4 allens. I do that because I take the engine out from the chassis often either to inspect or to mesh the spurs and pinions properly. I can loosen or tighten the engine screws easily with a T wrench and not afraid that the engine mountings will come off loose and strip your spurs and pinions

Yup, sounds like it. After 3 or 4 seconds idling, does it bog down or make a gurgling sound trying to rev up? If that's the case, the low end needle is indeed on the rich side. Another way to test is to use a pinch test. Press / pinch the inlet fuel into the car when the engine is idling. It should idle 3 or 4 seconds and then die off. If the engine dies almost immediately after you pinch the fuel tubing, then it's your low end is lean. Longer than 4 to 5 seconds and your low end is rich.

markp27

Yep, exactly, it gurgles and splutters and then cleans up. Thanks for the tip with the fuel pipe, I'll try that too.

Cheers, Mark.

serpentracer1

Hey Initial,No I havnt come from the HPI threads I used to post on thier thread years ago when they first started the thread but Ive been on so many threads in the past I really dont remember.I talked with yall a month or so back and told ya I was getting a new car and was undecided on which one to get that I had 2 impacts and the original impulse spec car and enough parts to make another.Its been 3yrs since ive been racing and in the month or so that I decided to get back in the hobby Ive started remembering things go figure.yea the side belt does fit on the car with the 25 pulley on it,its abit snug but with the washer on the front layshaft it works fine Im using my spec impulse as a test car with the different things before I go and build the 705 Im just waiting for a few more parts to get here so I can start on the car.Looking forword to it.I got a newer kit the date on the update page is 07-02-03 which is great.about the belt on the side yea I went thru all my losi stuff and got close a few times on the belt I wanted to run one of their belts(high perf blue, or green) cause they really dont stretch to much.The belt on the serpent is 120teeth if you say a yok belt will fit the car Id like to get the part number so I can try it out .Hpi used to make a 122tooth belt at one time and now it is only in the micro which is not wide enough so Id like to ck the yok belt out.Yea its great to be back in it again cant wait to fire the car up once its built

modellor

The Yokomo Side Belt is part number ZE-351. Should be around $3.50 - $4.00 at Speedtechrc.

Another problem with 705 is that the steering rods tend to rub the belt and can give a bad tendency to upset the steering at times in high load corners.

There are many different ways of dealing with this but the best I have found so far is to use the Yokomo servo saver and steering rods. They fit straight on with having to modify the plastic eyes or mount the servo from the top of the radio plate (which raises the CG). The part numbers for these parts are ZE-006W and ZE-200.

serpentracer1

Thanks for the part numbers and the tip about the servo.Have you tried to lower the servo more or can it be done.

modellor

Most servos sit too low already. They are rubbing on the lower side of the belt. I believe only the JR servos fit without any problems.

Some people mount the Serpent steering rods on the top side of the servo saver and cut away a bit of the plastic end to allow them to fit. We tried this here and found that it makes the plastic part a bit weak.

The Yokomo steering rods fit straight on top without any modifying and they are the ball cup type which I prefer. They also bolt onto the steering arm instead of popping on.

serpentracer1

Yea I use JR digitals in the cars I have I'll have to take a good look at the servo saver and see never had the problem on my original spec car..Thanks for the advice