MVVS .26 engine setup
 

I recently purchased an airplane that has a fairly new MVVS .26 engine on it. This is my first MVVS engine (I have all O.S. and Saito's in my fleet currently). I tried to start it last night and can't get it run/idle very smoothly (it won't idle at a low rpm very well). The manual does not do a very good job at explaining the setup. This engine has an adjustable "idle-running screw" on the opposite side of the carb needle valve. I kinda messed with it a bit trying to see if one spot was better than another, but had mixed results. Since I am unfamiliar with these engines I thought I'd asking some advice from anyone who could give it in helping me out before I spent lots of time trying to figure it out myself. I guess I'm just more familiar with my existing engines that for the most part didn't take too much tinkering with besides breaking them in and tuning the engine with the needle valve. Thanks and I look forward to any advice!

Trent

RE: MVVS .26 engine setup
 

A MVVS can take a while to run in. It is also likely to be a combat version if it was sold in the US and will have a BIG hole in the carb. Having said this run it in [ I would use castor min 20% ] Then establish a good full throttle setting on the needle. Set it to just below half throttle and apply the pinch test [pinch the fuel line and the rpm should rise a tiny amount before dropping ] adjust the slow running till this happens. If it is going to throttle it should do so now. Both the MVVS I owned had good throttles.

RE: MVVS .26 engine setup
 

Trent, I just picked up an MVVS .26 brand new. Haven't tried running it yet. I did see a post that said it was designed for low or no nitro, so got some 5% and will add castor.

Are you sure it's broken in, i.e., holds a just-lean setting without overheating? If not, no point messing with idle till it will. Are you familiar with pinch tests for adjusting high and low needle? Did that fail to work?

I suspect you won't find much direct experience with this engine, but there is a dealer or former dealer who frequents the Glow Engine forum, Dar Zeelon, who might be helpful. I'm going to follow along on this since I may need help myself!

Jim

RE: MVVS .26 engine setup
 

what is the caster for? i have a new .26 that needs to break in. what do you do with the caster oil?

RE: MVVS .26 engine setup
 

you drink it too help that sick feeling you will have in your stomach when you realize that you may have a bought a engine that ...............................")







Just kiddin

RE: MVVS .26 engine setup
 

Jim, Thanks for the note!

I worked with it the other night and finially got it going and running somewhat good......

I an using Byron glow fuel, 10% nitro/20% castor. With this small engine it was setup on the plane w/o a nose cone so I was chicken stick starting it. I think where I ran into some problem was when my chicken stick was bumping the needle valve on my up stroke and was leaning the carb. I had a buddy come in to help me figure this out and after quite sometime we got the engine going and it's running pretty good right now. I found out I can get my electric starter on the nut and washer and can spin it over w/o chicken sticking it. It still has a little mind of it's own and needs to get wound up quite a bit before it fires and gets going so I still ma need a little tweaking. The guy I bought this from said the MVVS's take a long time to break in and from the looks of it it's still pretty new. When I did get it up and running it was a big time screamer, esp. with my tuned pipe on it. I used my tach on it and got a 17000 rpm reading.

I have briefly heard of the pinch test but if you could explain it to me in detail it might help with the tweaking. Thanks again!

Trent

RE: MVVS .26 engine setup
 

Hi!
I've been servicing MVVS engine since 1992 and can assure you that MVVS engines do not need any longer running in time than any other modern engine (means no time).

Castor oil isn't needed either. Over here in Europe 15% all synthetic oil is what most of us use. But if you cannot get the oils we use, Motul "micro" and Aerosynt 2 and 3 then ...use at least 20% oil. Whether this is straight synthetic oil or Castor or a mix...doesn't matter.

The MVVS.26 engine with it's big golden top head is supposed to be used for Aircombat competition...but it could of course be used for sport flying too as the engine is just an ordinary sport engine, the only thing being different from the other engines in this series (.21, .25 and .28) is it's big head.

Carb functions as any other R/C carb with metering function. It has got two needles , one for high speed adjusting and one for low speed (idle).

All modern MVVS engines (with blue or golden head) could be run on 0-15% nitro fuel.

A good prop to start with is a 9x5 APC, provided the black mini pipe is used. There is a more quiet silencer made for the engine though for those that require a less noisy engine.

A good glow plug is a Nova Rossi 4 or 5.

Tank size 150cc . Best tank is a Tettra "Bubble less" or second best a ordinary tank set up with "Uni-flow" system (two clunks)

RE: MVVS .26 engine setup
 

Hi Jaka

Got to take exception to your comment on running in. In the UK the MVVS 20 is a popular combat engine. Based on my own experiences with those and a 26 and seeing another dozen or so engines most definitely need some running in [30 mins to 60 mins ] before they will hold full thottle for seven minutes. Some are really tight when new!

RE: MVVS .26 engine setup
 

Jan, thank you for weighing in. My engine has no large head and no anodization, and the muffler seems to be a rather small plain expansion type. Manual says it's a .26, which seems to be no longer made - I gather the .28 is the replacement - appearance is very similar.

What is the relative heat of those Rossi plugs? Will I be able to run a 10x4 on this engine, or does it need to rev more?

I may want a quieter muffler. Where would I get that? Thanks in advance.

Trent, I do the pinch test with a needle nose pliers near the carb. As the moderator said, you want a short rpm rise when you pinch the line. If it stops abruptly, it is lean. If it revs up for a few seconds then it is rich. For the high speed needle I just go by sound, but I find the pinch test very useful to set the low speed needle. Final test, if you let the engine idle several seconds and then quickly advance the throttle, it should accelerate quickly and smoothly. If it hesitates and produces smoke, it is rich; if it stops suddenly it is probably lean. If you have done the pinch test, it should be fine.

Maybe Jan will tell us if this is a good method for the MVVS.

Jim

RE: MVVS .26 engine setup
 

That 26 sounds like an older version sold in Europe and might be the same as the one I had. Std head and a small volume single compartment silencer. In the UK we have a fairly strict noise policy at many flying sites [ 82 db at 7 metres. ] there is no way I could get it anywhere near that with the std silencer and passed it on via fleabay. It was a good engine though.

RE: MVVS .26 engine setup
 

the one I have has the big gold head on it. Says not to run more than 5% nitro in it. Brand new. I haven't even begun to break in because I haven't gotten any fuel with 5%. I only have the 15% right now.