DBuck42

My Feedback: (3)

I was looking to purchase two HPI Nitro MTs for my son and I to bash around, but decided to purchase the Ultra MBX Pro instead. Just purchased a brand new older version of the Pro with the P4 .25 engine off bay for $299.00.

I am seeking input as to what should be done to the buggy prior to running. Please post any recommendations.

What should I locktite on the buggy? What about diff oil, should I take apart and oil myself? If so, what type of oil should I use? Is it critical to replace the steering servo right away? Can someone provide me detailed instructions as to engine breakin?

Thanks for all the information all have shared through this forum. It has enabled me to make a purchase decision which best fits my needs. Keep it coming.

Nitroaddict

dbuck - welcome to the 8th scale world. to answer your questons....

lock tight everything bolt that is screwed into metal. if screwed into plastic, a little ca will work.

diff oil - not needed at this time. u might want to upgrade to it once you learn how to drive well. when u do, any brand will work, and the wt will vary depending upon the surface.

a powerful steering servo is manditory, however, feel free to use the one u have until it breaks.

engine break in - just follow the instructions in your manual. take your time, and make sure you have used at least 4-6 tanks of fuel before u begin to lean out the engine for power

most of all - have fun!!!!

DBuck42

My Feedback: (3)

Please give your input. Thanks!

studysession

Listen to what Nitroaddict said - he knows his stuff. Especially the loc-tite and follow all break in procedures. You will not be disappointed.Nitroaddict

DBuck42

My Feedback: (3)

What type of locktite should I use on the hot engine parts? Thanks!

studysession

I use the blue for all everything. But after a while the loctite wears down and have to redo everything once and again. it is good to do anyway to check and clean parts.

Nitroaddict

Dbuck - NEVER USE RED LOCKTIGHT!!!! You will never get the screws out. Use any local brand of blue locktight.

Also - the ONLY screws on the engine that you should locktight are the actual engine mount screws.

DBuck42

My Feedback: (3)

I once purchased a brand new engine and started it without taking it apart and cleaning it. The first time I started it the engine froze up because of a metal shaving was inside the engine. When I get the new Ultra MBX Pro and 9.5 RTR should I take the engine apart and rinse it clean?

Nitroaddict

Dbuck - that would be totally up to you. I have never heard of what you described in 12 years of RC racing. So i would assume that it was a one time thing, and wouldnt expect it to happen again.

studysession

On a new engine - I have never taken them apart. Only take them apart when there is a problem.

Razoo

My Feedback: (2)

I also locktite the cooling head screws. Other than that Nitroaddict covered all the bases. I highly recommend a fuel filter and failsafe

Nitroaddict

Do not, i repeat, do not locktight cooling head screws.

Maxxer

My Feedback: (1)

why should you not locktite the cooling head screws?

Nitroaddict

due to heat expansion, if the screws are locktighted, they will almost never come out if left in for a good period of time.

DBuck42

My Feedback: (3)

Thanks for everyones help. Any recommendations on fuel to run in the .25 and .26 engine? I am thinking I would us the OFNA recommended Byron 20%. I used Trinity Monster fuel 20% with great success in the TMaxx I just sold.

ShOzz

30 % in that buggy is a blast...
i have tried about 4 or 5 fuels and decided i really do like odonalds, i saw more speed from it over the others i tried and very low temps at 30% nitro.

studysession

Yeah as for the temps - you can get lower temps with the higher % of nitro. The higher % fuels are designed for that some how they do it. I don't care how, I just lvoe that they do.

I run Model Technics 25% race blend myself. I used to use Blue Thunder 20% race blend in the US and this gives me more boost and lower temps. Can not go wrong there.

DBuck42

My Feedback: (3)

Thanks again!

Which glow plug works the best in the .25 engine?

Which glow plug works the best in the .26 engine?

The Ultra MBX Pro that's in the mail is not coming with a glow plug. This bubby is coming with the .25 engine.

Also have the 9.5 RTR coming from Nitrohouse as part of their moving liquidation. I am assuming this buggy is coming with the .26 engine installed. Does it come with a glow plug?

studysession

It is supposed to come with one - But mine did not for some reason. OFNA says you need a long glow plug for those engines. After all the trouble I recently had I believe they are right.

I got it started with the OS #8 but not reliable enough. I put in a long plug from Fantom now it is easier to start. The fantom plug is a gew mm longer.

DBuck42

My Feedback: (3)

Any other recommendations as to glow plugs to use with the .25 and .26 engine? Can the same plug be used in both engines? Happy Thanksgiving to all!

p.s. I read an update on the OFNA website about the .25 engine. It says that some people have had problems with the engine backplate coming loose. They recommend taking the engine apart and locktighting the backplate screws and start cover screws. Has anyone had any experience doing this? What type of locktight should be used? Is it hard to take out and put back in the engine? Any recommendations from the experienced crowd wouyld be greatly appreciated. Thanks!

studysession

Can you post a link for the update? That is good info. Next time I take my 9.5 apart I will check my back plate.

As for glow plugs - I called Nitro House last night and ordered 2 different kinds of glow plugs.
I wanted to compare, one was McCoy #9 and forgot the other. They work in both the .25 and .26 engine.

DBuck42

My Feedback: (3)

Here it is studysession:

http://www.ofna.com/recall.html

The manual of OFNA's website for the 9.5 RTR and Ultra MBX Pro says Not to use McKoy 5.9 or O.S. # 8 plugs. Have you tried the OFNA/PICCO plug recommended in the manual?

Thanks!

studysession

I am using a plug that came with my Fantom engine at the moment. I called Nitrohouse and just asked them what do they use in the Force engines. I have hard time getting it started with the #8. I would not receommend it either.

I might be worng on the McCoy #9 - I did not write it down. I only wrote down the prices. They said same thing about the OS plugs and using them in the Force engines.

I read that recall - I saw in another post where a guy was pissed because that is what happened to his engine. The back plate came off.