Ovation Mikuni Conversion

ovationpaul

New member
Joined
Dec 23, 2022
Messages
2
Age
43
Location
Helena, MT
I will start by apologizing for asking a redundant question. I have searched at length and have found much great information. However, I still have some questions. Thank you in advance:

I have a 1989 Yamaha Ovation Deluxe (Electric start). It has been in my family since new. My grandfather bought it new in '89, I bought it from him in '97, sold it to my Dad in '02, he gave it to my son in 2016. My son is now old enough and big enough to ride it. All of that said I have been working to revive it.

I would like to install a VM series carb on it. I have the Enticer manifold, carb flange, new genuine VM32 carb, and a snow specific UNI air cleaner.

I would really like to retain the oil injection. My first question is: How do I control the carb and oil pump? I thought I could get a cable from a single carb sled (early 90's cat or similar) and use that. My second question is: Where is the best place to inject the oil? Continue to mix in the fuel or inject it separately at the manifold?

Any help is greatly appreciated!

Thank You!
 

You will need a split cable to function the oil pump. A cable off a cat or something similar might work. That is going to be the tough part of the project finding a cable with the proper end to couple up to the pump.

If you have the enticer intake manifold. There is oil injection spigots on the bottom side of the manifold.

I am running a 38mm VM carb on my Enticer with a snow filter. Removing the air box and bigger carb increased the rpm to 7700. I had to install a first gen Phazer primary clutch and run the 8VO ramps to pull rpm down.
 
What is the advantage to going away from the stock carb and airbox, aside from gaining some peak HP?

I always thought the run quality was quite good on those machines.
 
Performance mainly. I find throttle response is better. No lag time between pilot jet and main jet. They will cold start better with a vm carb as well. The choke circuit is richer.
 
Last edited:
Thank you for the info. I have ordered a split cable for a cat. Hopefully I can modify the oil pump end to make it work. Through this process I have discovered I only have 60 lbs of compression in each cylinder. I'm assuming that I should have north of 100? I feel like I should correct that issue before I go much further with the carb swap.

Thanks again for the information!
 
Yeah it should be 120ish with throttle wide open
What did you end up with for carb settings.
Needle jet.
Main jet.
Cutaway.
Jet needle.
Pilot and main I've always found to be the easy part, it's finding the right needle jet on any given engine.
 
Mine is a 38mm. It won't be calibrated for a 32mm.

38mm
350 main jet.
50 pilot jet.
6dh2 needle. on center clip position.
247 Q-2 nozzle.
3.0mm cut away.
1.5 turns out air screw.
1700ft here.
 
Mine is a 38mm. It won't be calibrated for a 32mm.
I don't have any carb yet. I just thought if I ever attempted this I was curious to your settings.
I have an AEM A/F digital guage. I would probably mount the O2 sensor in the exhaust to monitor and make adjustments from there. I can't think of a more accurate way than that.
 


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