LOSA4444

Aluminum Split Top Center Diff

This is no secret and if you have linkage issue you should get this, so you can stop trying to find that happy medium for the carb.

You can run your carb at the correct 90* angle for a straight pull from the servo without having to worry about your carb being to close to the center diff so that you tear your carb boot from hitting the center diff from chassis flex, or to solve that issue (which I had on all my engines) you run the carb at such a goofy angle to keep it away from the stock diff mount the linkage binds.

I run a Werks B7 currently and have 0 issue with linkage. I do have issues with my finger sometimes as the B7 is a beast of an engine in Buggy.

I also run OS engines and had the same issue with all of them and the stock diff mount. Either I ran them at a goofy angle and they were ok, but not as smooth on the carb slide, or I ran them as close to 90* as I could and replaced carb dust cover boots after a couple races.

I'm not saying you have to get the new diff, but it makes a huge difference. I was able to get all my engines running fine with 0 issues, but they were all at goofy angles and the carb slides weren't as smooth as they were when freed from the linkage, and I could have easily had an issue at any moment.

Hope this helps the Losi guys that haven't already got this or dremeled some of the stock diff plastic.

lol thanks for the suggestion

Naa it's not that. we were breaking it in ... in my car and i have that mount. It was binding on the bench and in the car.

i am gonna order one lets see how it goes for me.

I just re-read my post and I think that I came across as an arse lol, sorry about that! I was not trying to say that you were in any way shall we say unhappy with the service or anything. What I was getting at was that after you go through 3 brand new carbs and one that was used in Kortzs car and we new perfect, and you are still experiencing a carb sticking issue it's prety obvious at that point that the issue does not lie with the carbs but rather with something else. That was basically what I meant to say, just came out wrong!

On Placks engine if you could pop the linkage off and pull the slide open by hand and check to see if it moves smoothly. If it moves smoothly by hand with no stickyness then then take a look at the linkage as you might need to alter the snap ball position ( the one connected to the slide) as it is probably pulling at a slight angle which is trying to rotate the slide in the carb housing. The only thing that will stop the slide from rotating will be the side of the idle stop groove (which is machined into ths slide) being forced up against the idle stop screw. Needless to say any time you have metal being forced against metal with 100+ oz/in of toque something is going to stick.

If with the linkage disconected and moving the slide by hand you feel binding completely unscrew the idle stop screw. Now holding the slide in the same position as it was when the idle stop screw was installed, slide it in and out and see if there is any binding. If not then take a look at the idle stop screw to see if there is any burrs on it, if so you can remove them with a scotch brite pad or the edge of a xacto. Then pull the slide out of the carb and check the idle stop groove to see if there are any burs on the edge. Easiest way to donthis is to run a x-acto knife along the edge of the groove at a 45 degree angle, if there are any burrs it will catch. You can use the edge if the knife to de-burr any if these also.

If everything looks fine then put a couple drops of after run on the slide and re-insert into the carb body. Move the slide back and forward to make sur everything is smooth. If it is line up the idle stop screw with the groove machined in the slide and slowly screw it back in. I say slowly because if the idle stop screw is not lined up with the groove it will be forced against the slide which can result in a bent idle stop screw, so please watch this. Once the screw is starting to sit in the groove but before it is screwed in far enough to hold the slide open any move the slide back and forwards to see if there is any binding. If not continue screwing it in until you are holding the slide open the amount that you want and then test again to make sure everything moves smoothly. If it does you are good to go.

Now I think it is also important to point out to everyone that especially during brak in when you are running realy rich low speed needle settings it is possible to have the slide held open so far by the idle stop scre that it can bind. This is not unusual or I should say not a problem with the carb (as every carb will do this) it has to do with the angle that the idle stop screw ends up sitting against the slide when extended an extreem amount. Off the top of my head this is going to be around a 2mm opening on the slide or so. When you see this just back off the idle screw a half turn or so and it should go away, again as I said this is usualy only during break in where you are trying to run large air gaps. If you back off the air gap a bit as mentioned above it is not an issue, just lean the LS an hour or two to bring the idle back up.

Hope this all gives you some things to look at. Please let me know if this resolves the issus thT you were seeing with your buddies car.

Regards,

Ron

yep....stock restrictor. Should I expect more runtime than 10 min flat with the 2057? or is that decent?

Thanks 871

with it only running at 200 degrees i would think 10 min is really good. you could lean it out a little more to raise the temp and get better runtime.

I spent last weekend breaking in two B5's, one for my RC8B, and the other for my RC8T. My buddy Pete helped me break in the truggy engine - we ran into a few minor issues, but nothing major (we ran into the carb-binding issue that Ron mentioned a few post back by opening the idle gap too far - we were puzzled for a while, but we figured it out ). We used the 'Werks Recommended Engine Break-in Procedure (tm) by running the engine super rich for the first tank to flush it out, followed by repeatedly closing the idle gap and leaning out the LSN. Ran through 3 tanks doing this, followed by a couple of medium speed runs to see how the engine was doing. I think when we were done, the engine temp'd out at about 190....

I broke in the other engine myself (nervous, didn't want to fry the engine), but after getting the engine idling properly (was waaay too rich on the bottom end), I followed the same procedure as above. Worked out pretty well. Without doing any speed runs (just figure 8's), the engine maxed out at 175...

Both engines, by the end of the initial break-in, were starting to get reasonably snappy. I'm used to 1/10 on-road electric 'snap', but this was still impressive. Considering how much weight is being moved by these small engines, I was suitably impressed by how much acceleration you do get. I'm sure I'll be even more impressed once we hit the track and finish the break-in/tuning process...

So, while I don't have any previous off-road experience to compare to, I'm suitably impressed by the B5. I'm certainly not disappointed by my purchase!

Now, when can I hit the track?

You can do it like Mo, and finish the break in while racing once you get a few more tanks run through it. I know we were breaking in his engine this weekend and it is such a good engine that he was running away with the main and then that friggin Mugen wing problem lol. But I honestly don't think his engine is completly broke in yet. But he was doing VERY well with it still breaking in. Just to show you guys how good this engine really is.

after running 3 tanks through it on race day before the race it wasn't even 200... and honestly i'm not sure it was 200 after the 35 minute a-main and it was still performing VERY well... Very well could have won the main if it wasn't for those extra pit stops for me to shove a screw into a slot for his wing to stay for a couple of laps...lol

-DC-

Wow does that sound familiar.... I ran Losi for 2 years and all you Losi guys know about the issues with the throttle setup and binding carb slides but out of the blue one day I lost a servo due to a binding carb slide but I had that issue taken care of by dremelling the diff mount and adjusting the carb angle and I was good for over a year with it but my carb slide started to bind again....so I replaced my servo and re-adjusted my carb and I was good....put the car on the track for a few laps and brought it in for a check and wow binding again..took it to the trailer and yup it was binding when I pulled it by hand...re-adjusted and it seemed good, back to the track and the same story...well 2 servos and 3 different carbs later it was doing the same thing...but it would only do it when the engine was at race temp. I was lost......until two weeks later my race buddy who I race with every weekend lost his throttle servo and developed the exact issues as me...being we run the same fuel out of the same bottle we came to one possible conclusion that something was wrong with our fuel and we ditched what was left of our fuel stock and got a fresh batch of the same fuel and BAM....all our issues went away....I don't know what was wrong with the fuel...it was not old and the color was good...all I can assume is it was a bad batch and something to due with the oil mix but the point of my long story is if you tried everything possible trying a different batch of fuel might just be the answer although a rare one....good luck!

Question for Ron or anyone that has the answer.

My calipers are dead and I need to know the size of the Heat Sink/Head Button screws as the stock flat head ones have started to wear and strip a bit and I need to replace them.

Thanks in advance.

-RJ

Wow this is really funny.... This is no BS. I was running Odonnells 9% oil it hung up when hot. Changed over to Sidewinder 11% oil, didnt hang up once raced a whole day not one hang up hot or cold. Ran out of sidewinder and changed over to Werks 9% oil. Guess what it started hanging up again when it got hot. Maybe it does have somthing to do with oil content or type of oil in the fuel. Because like I said Ive tried everything possible..........

Almost got 2 gallons on my B5 and the carb never hung on me. I run Odonnells 30%, comes off the track at about 220F. I also run it in a Losi 2.0B rr. I did put oil on the barrrel and work it for a good 4 hours before starting. Borring, but something to do when watvhing t.v.

I was driving my car and the motor is running good but when it idles for about 5-6 seconds and i start to give it a little gas its starts to act like it wont to die and then if i give it more gas it will go.

might be just a tad rich on the bottom

Replace them with hex heads an your good to go. They are 3.5 x 16

http://www.tonysscrews.com/product.s...3&categoryId=3