Rainy Day Project - Mugen MBX 4

[shredder]

Well, with the rainy days and no work, I decided to pull my 8th scale nitro buggy off the shelf and dust it off (at least thats what I thought). My kid has been bugging me to get both of our nitro buggies working so we can take them to Lake Forest.

I have a Mugen MBX 4. I know this is an old buggy, probably 10+ years old (I don't even remember), but I have really enjoyed it and have not thrashed it. I especially like the Nova Rossi Motor, maybe because its Italian....who knows.

After taking a closer look, I decided that after a decade+ it should probable be gone through. So I basically, did a complete tear down to clean all the grime, replaced 8 bearings, etc.

Here are a couple pics after getting it mostly back together. I need to clean up the engine and retune it, connect and adjust all the servo linkages, and correct the steering. This last one puzzles me as the sterring was dialed in before I took it apart and now the wheels are not straight. Makes me feel like I missed something. Will have to look into this some more tomorrow.

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[Darkstar]

Nice buggy, it was my first 1/8 scale back in the days of good old Ranch Pit Shop in Pomona

[shredder]

Cool, I always wanted to race, but after they closed Mile Square Park, I just didn't want to have to drive to Hemet to practice, play and race. I think I saw recently that there is a track now in Temecula, but I don't know where. And I'm not sure how competitive this buggy would be anymore anyway.

[shredder]

Well, I got my buggy back together. I had to paint the outside of the body as the old inside paint was cracked and peeling. I'm not sure how this will hold up, but it seems to work ok for now. It took several weeks to get the engine running decent. When I first started it up it acted possessed as the idle and throttle were all over the place. It would seem that these were caused by air leaks. Sooooo, I took the engine apart (again), replaced all the fuel lines and o-rings (which were very difficult to find), and applied hi temp silicon to the carburator base and the rear plate. That seemed to correct that problem, but then the servo gave out. Not sure if the gears are stripped or what, but the throttle just became unresponsive. So finally after installing a new one, I have been able to start driving it. It has been fun the last week or so. Now I just need to drive it and fine tune the engine. When I drove it on Sunday, it ran well enough but I only got to 201 degrees (optimal for this engine is 220-240). I know I can lean it out some more to get a bit more performance, but if it runs well enough rich, then I should be able to make the engine last a bit longer...although I will go through more fuel. Here are a couple pics of the finished project.


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