Yamaha RX1 Engines

562 posts in this topic

Posted

I think the this biggest factor as far as starting is the prop diameter and moment of inertia. I don't have any problems starting on my trikes but Im running 68-70"  3 blade light propellers. I usually start with the enricher (choke) open and the throttle cracked open. When it fires I throttle up a bit and close the enrichener. Most important thing to remember, if it ever fires up but wont get past a really low idle just shut it down because it will just shake and idle really low. Enough shaking to possibly knock your airbox off or damage of stuff eventually.

Share this post


Link to post
Share on other sites

Posted

Thanks for the tips guys

Share this post


Link to post
Share on other sites

Posted

I managed to get a hour flight in this morning in the avid with the Rx1 engine,It ran nice and smooth and climbed at 800 ft/min at 7500 rpm without trying, I could easily cruise 6500 rpm @80-85 mph and stall without and flaps was around 50mph , was awhile coming but it seems worth it :BC:

rx1avid.JPG

rx1flight.JPG

1 person likes this

Share this post


Link to post
Share on other sites

Posted

stalls at 50?

Share this post


Link to post
Share on other sites

Posted

 Forgot to mention there was 2 of us in the plane , im not to sure what it is with me in there , too busy watching the ground lol

Share this post


Link to post
Share on other sites

Posted

That cowled out real nice Marshawk. Is that a Subaru Cowl? 

I got my Skytrax and C gearbox mounted on on my RX-1 engine this weekend. The instructions were staight forward and Teal was great about answering my many questions and providing input. I also recieved my wiring harness, exhaust flanges and engine mount parts. 

I would love to hear about what propellers have proven to be effective on this set up or what others are planing to use.

Share this post


Link to post
Share on other sites

Posted

   It is a kitfox 5 cowl, the same cowl that I used for the subaru, its a snug fit but it works. Teal was very helpful with me as well. As for prop I am using a 72" 3 blade warp drive , it seems to be working fine,I haven't started playing with the pitch yet it was still the same pitch from the soob engine, for some reason the last bit of throttle doesnt seem to do anything so were thinkinjg we need  to service the carbs,  so want to do that first,in the mean time it seems to fly fine at 7500 max rpm

Share this post


Link to post
Share on other sites

Posted

If you pull those carbs apart be real gentle with the needles. The plastic part that holds them in place is real easy to break if you push them down too hard and Yamaha doesn't sell just that part. Also don't forget the tiny o-ring underneath the carb cap.

 

 

Ken.............

Share this post


Link to post
Share on other sites

Posted

sure looks nice

Share this post


Link to post
Share on other sites

Posted

Thanks Tjay and thanks for the tip ken

Share this post


Link to post
Share on other sites

Posted

Just a word on your comment about the last bit of throttle not doing anything. Your kind of running the engine at a low max RPM. When you do this the throttle response changes. you might find that by increasing your rpm another 1000 (flatten the pitch) your throttle will behave a little different and you may even get better full economy. I know it sound counter intuitive. remember these engines develop their max HP at just above 10,000 RPM and the snowmobile racers are running them up to 11,000 RPM frequently.

Share this post


Link to post
Share on other sites

Posted (edited)

Thanks Teal, I'll try playing with the pitch this weekend and  get another 1000 rpm and see if that changes the throttle issue

Edited by marshawk

Share this post


Link to post
Share on other sites

Posted

Have the RX-1 engine with the Rotax C gearbox and Teal's cool adapter mounted and the header built in a Zenair  CH701 . I am after options for radiator choices and optional oil tanks. What have you used?

All input welcomed.

Share this post


Link to post
Share on other sites

Posted (edited)

I like the clean install of the  polaris razor radiator that teal has done!  Pic below is all I have.  It mounts to bottom of engine mount and does not penetrate out the cowl or into the airstream, rather it is flush with the cowl and presumably  gets flow (downflow) pushing through the cowl openings near the prop.  Maybe he can post how well it is working down in the AZ climate.

And i personally plan to use the rx1 oil tank because it incorporates the low oil warning and it is designed specifically for the rx1 (albiet a bit ugly)

20170121_165300.jpg

Edited by MN Kitfox 2

Share this post


Link to post
Share on other sites

Posted

I will have to look and see how much room I have under the engine ,alot cleaner than mine  hanging down an if it keeps it cool in AZ I should have no problem up here, I also used the Rx1 oil tank  for the same reasons

Share this post


Link to post
Share on other sites

Posted (edited)

Just so you guys know , some of the early rx1 snowmobiles experienced some kind of cracking on the oil tanks because of vibration. It may have been caused by all the bouncing around that a snowmobile goes through which shouldn't be a factor in a plane but I would mount them with some kind of rubber bushings between the tin and the frame. Check out this link.

 

http://ty4stroke.com/search/682690/?q=cracked+oil+tank&t=post&o=relevance

 

Ken.........

Edited by givemeaboost
new info

Share this post


Link to post
Share on other sites

Posted

I finally got a picture to load to this site. Apparently the app I was trying to use is not photo friendly. I have been posting on the Yamaha site on Facebook but was asked to post here. I bought a 2004 RX-1 with 1200 miles on it. It took my three evenings to pull it out of the sled. I purchased an adapter from Teal which I've installed with a new C gearbox. This week I have been gearing up to build the engine mount. I managed to get the side rails built and installed. Now that I can load pictures to this site I will start sharing my progress. This is not going to be installed on an Avid or Kitfox but I hope you can use the information.

20170326_144645.jpg

1 person likes this

Share this post


Link to post
Share on other sites

Posted (edited)

Thanks much Vance!

Posting all that you have on the Facebook site is a big job in itself!  I'll try and put a link to the Facebook group (created and administered by Greg Mills of Mohawk Aero) so anyone here who is interested can join up over there.

That may help so you don't have to double post everything!

https://m.facebook.com/groups/1251356951570824?ref=bookmarks

Brett (aka "Anatoli" as my Facebook alias)

 

Edited by MN Kitfox 2

Share this post


Link to post
Share on other sites

Posted

Those that do not use Facebook would appreciate the info being added here. Thanks

Share this post


Link to post
Share on other sites

Posted

 I took out one degree of pitch in the warp drive prop which brought it down to 10 degrees , it only gained about a 100 rpm on the RX1,WOT was 7900 rpm at the 10 degrees and 7800 rpm at 11 degress, so we are back thinking it maybe a  carburator problem.I ordered a sync pro carburator tuner  and also maybe  a jetting issue, we are at 3000 ft asl, The experimenting continues .:unsure:

Share this post


Link to post
Share on other sites

Posted (edited)

I think that 1 degree = 100 rpm static change is what the prior owner of my EA-81 and 3-blade Warp Drive told me.  EDMO

Edited by EDMO

Share this post


Link to post
Share on other sites

Posted (edited)

Hi Ed, I wish I had a better memory but I think 1 degree = alot more than 100 rpm on my EA-81 with this same warp drive prop. I had it set at 11 degrees for the soob so im thinking the RX1 with more horsepower would be at least equal to that. If I was to adjust the prop pitch to get the 8500 rpm on the rx1 I would be around the 4 degrees pitch in the prop if each degree = 100rpm , :bugeyes:

Well I got a fast reply back from G.T. Mills and he is saying he usually runs his 3 blade props around 6 or 7 degress on these yamahas so I guess my logic is out the window  and will take a bunch more pitch out :BC:

Edited by marshawk
1 person likes this

Share this post


Link to post
Share on other sites

Posted

As far as jetting, i know steve henry would be a good resource.

Personally I like teal's use of the O2 sensor to guage air/fuel ratio.

But for a quick check to see how it is performing, I think I would start with a simple thrust pull check once you get it pitched for rpm.  People with experience chime in, but as I understand, a well tuned and healthy  rx1 should pull a bit over 500 lbs.

1 person likes this

Share this post


Link to post
Share on other sites

Posted

Hi Ed, I wish I had a better memory but I think 1 degree = alot more than 100 rpm on my EA-81 with this same warp drive prop. I had it set at 11 degrees for the soob so im thinking the RX1 with more horsepower would be at least equal to that. If I was to adjust the prop pitch to get the 8500 rpm on the rx1 I would be around the 4 degrees pitch in the prop if each degree = 100rpm , :bugeyes:

Well I got a fast reply back from G.T. Mills and he is saying he usually runs his 3 blade props around 6 or 7 degress on these yamahas so I guess my logic is out the window  and will take a bunch more pitch out :BC:

I guess that the difference in prop pitch and rpm gain or loss may vary depending on where you are on the torque/power curves?  EDMO

Share this post


Link to post
Share on other sites

Posted (edited)

Regarding carb set up.  I've talked with Steve quite a bit about his and last we talked he was running somewhere around a 180 main jet.  Everything I read seems like running a small air box or just filters calls for a rich environment.   I do recall him speaking highly of the holtzman springs.  I very interested in what others are doing here.  I should have my motor up and running on a highlander in a month or so.   Really open to prop suggestions as well.

Jody 

Edited by Copro
1 person likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now