Morspeed

I have had a few defects from new in my Zen 260 pum, one serious, and a few troublesome manufacturing/assembly issues, all good now and am still reasonably impressed with engine, however I have heard about a BM260 copy motor, can anyone tell me who makes and sells these and are they any good, I am building a couple of 52" mono deep vees at moment and am looking for reliable powerplant without breaking the bank.

Also I am heading to LA for a few days in October and ask if any one has any contacts for dealers in LA for these motors (Zen and copy BM 260) as well as hardware suppliers (drives,rudders etc..).

Thought I might like to do a little shopping while in the US.

Any help much appreciated.

Cheers.

STEVE MARSHALL

These guys have them, I got the stage 2 mod for $300au. Might be worth the postage. I haven't run mine yet.
Steve

http://www.rcjets.com.au/rcjets_catalog/index.php

TIA

When in October will you be here?

Full mod Zens are about $500.

There will be a huge gas race in Las Vegas on the 27th I believe.

Artie

Morspeed

Steve, cheers for that, would be great to hear how your BM stands up when you get it wet, do you know if piston,rings, head etc are interchangeable.

Artie unfortunately I will not be there for the Las Vegas meet, love to be there but have to get back to work in NZ.

Only in La from 10th - 16th Oct.

Cheers

Gary

STEVE MARSHALL

dreamwakes, as far as I know everything is interchangible with zen parts, the stg 1 and 2 motors have a bit of porting work done. If you look at the engine pages he has all rebuild parts.
Steve
PS hows the fishing up there? Bay of Islands is a beautiful place. We used to stay at Sand Spit as kids, go from there to the hole in the rock.

Earth Surfer

A word of advise. I have never seen a "copy" of anything that is actually better quality than the orgional. The reason is, they are not smart enough or too cheap to actually make a better product--so they just copy it. Short cuts are taken, and quality suffers.

Morspeed

Hey Steve, cheers for the info, good to know, I have a handful of new spares for my Zen and it would be useful to be able to interchange, Do you know where these are made..China???.

The Kingi fishing up here has been great the last few years, had trouble landing any decent Snapper but plenty of Marlin coming into the Russell wharf last season, try to get out every few weeks over summer for a fish but usually too busy taking tourists out around the Islands.

Used to stay at sandspit myself a fair bit - nice part of the world down there.

Earth surfer..I hear you on the quality issue,someone out there must have first hand experience on the spec and quality issues which is why I was trying to find someone who could give a unbiased qualified report before I commit.

As I said I my thread starter , I have had a few issues with my Zen so can't really say they are a top motor either.

STEVE MARSHALL

I just had a look over my motor and the box it came in, No markings at all, From memery they are made in china. Good to here the fishing is still good up there, I will have to con Dad to tow the boat up their next time i am over for a holiday
Steve

TIA

MMMMMMMmmmmmmm...... What issues did you have with your Zen that would be inherent to all Zens????

Morspeed

Whether the problems are inherent to all Zens I cannot say, but I have had a bad run thats for sure. When running sweet it is a excellent motor and I would buy another, there are just a few things I would check before starting out of the box.

The most damaging fault was when after about five or six runs (from new)she stopped dead in the water.

Could not get her to turn over at all, thought I had a seized engine on my hands, stripped it down and found a very small (and squashed) grub screw jammed between bottom of piston and cylinder wall. The screw was the one that secures the throttle butterfly to the throttle shaft- it had clearly worked itself loose and been sucked down the intake port, fitted a new screw (with threadlock) and machined the damaged internals to get it running again.

However, way before any of this I was having trouble getting the engine to run at all and after alot of head scratching found the two bolts that secure the venturi and carb to insulator block are about 1/8" too long and jam into cylinder head when tightening meaning the carb does not secure firmly onto head therefore allowing for a very small air leak.

And then after all this (and replacing the Cyl head gasket) a small leak became apparant between head and crankcase- not much but enough to allow loss of crankcase pressure and fuel/oil mix to escape.

On closer inspection discovered that the crankcase/ head join surface was not a perfect machined surface on the exhaust side (right where the two halves of crankcase join)- I had noted this from new but did not think much of it as it did not seem to present a problem. This was allowing for the leak and requires a tiny smear of gasket cement to remedy.

As I said , still like the motor- just would run thru this checklist before giving it the message for the first time.

TIA

LOL! I've heard of those screws falling out a lot. I think thats the first thing you do when opening the box is locktite those baby's in.

The other I've never heard of before. Maybe you're just lucky?

Morspeed

Yea mate, didn't seem so lucky at the time, looking back it all seems so easy to prevent but instruction manuals don't mention these things happening.

MrMikeG

The case halves are machined as one so if yours were uneven you may have had a motor built from spare parts. Carb screw is a carby problem, not really a Zenoah problem but I would still be alerting them. I'm sure they don't have time to check each one but they can go back to Walbro and alert them. Another common occurence is the flywheels not done up tight and the key shears after a few runs. Just normal things to check with any new engine. Heck I have seen new nitro engines with shavings still in the case from machining, way more $$ than a Zen. [8D]

Morspeed

Mike, if your brand new car sucked a peice of carby down its neck and you threw a piston, how happy would you be to hear its not the car manufacturers fault or problem, I have not alerted Zenoah to this issue however if you have a good quality control sytem in your manufacturing arm as well as OEM part suppliers, this would not happen.

Don't get me wrong , I really like my engine, It would have ben nice however to know these were potential problems that should be checked before running, In a way doing a prestart check up (from new), and therefore managing the quality control for the manufacturer .

bermudaguy

from running nitro i KNOW to pull down any motor i buy before running.
its not the same for a street car cause 'they' start and drive it before u get it so if its gonna break on start up its on them

thevirginian

I herd about almost all of these problems before I ran my Zen for the first time. Checked my motor over and found nothing wrong. Only thing I did to it was I machined a relief on top of the piston to prevent it from seizing up- a common problem with new Zens. I love my Zen.[sm=cool.gif]

bentley marshall

the old mans talking about selling the boat bro .......any way it would cost to much to tow it up there with the bedford

gofast53

I have tested both a stage 2 mod BM 260 and a stock Zen 260 in my AM Avenger to compare the difference. The Zen came out on top as the BM 260 did not seem to want to rev as high as the Zen, even tried changing the BM coil over to a Zen one, as I read some where that the BM coils restrict the revs. But this made no difference.
Parts on both motors are pretty much identical, apart from the magneto and the pull start.

Morspeed

Ok , so I have been at sea for the last eight months and have just caught up on this thread again, I went ahead a purchased another 260PUM while travelling thru the USA and will do some thorough checks before running up but the post from the Virginian caught my eye, "machining the top of piston to prevent seizing" could some one explain why exactly and how to go about this??, much appreciated.

Cheers........Gary