1991 & 1983

[dna9656]

Will a 91 engine fit a 83 frame? Is it a good (worthwhile) thing to do? I think there a lot of modding to do...

[cowpuc]

Yep,, bolt right in.. The MK2's (91) had the diaphram spring clutch in em so the clutch cover is a little deeper but not to the point of interfering with anything.. TCI and carbs are different so you will want those from the donor bike. If I were going to do what you are talking about I would double check the frame on the 83 for proper gusseting - a really good buddy of mine had his fail ( @Venturous_Randy ) and others have too.. As far as modding goes - this is the only real essential modding necessary.. If you wanted to do some other modding you could do some modding to the front of the 83 - drop on a set of MK2 forks then add on some R1 calipers so the finished 83 would stop as well as it runs..

 

As far as being worth it,,,,, most of us 1st Gen riders around here sure seem to think so!! Mom Yam is the one who stopped building em,,, not us!!!

 

DNA - just did a quick search - take a read here,,, think you will find this VERY interesting!!!

http://www.venturerider.org/forum/showthread.php?66786-Rebuilding-and-Modding-my-83&highlight=engine+swap

 

:lightbulb:the advanced Yamaha Venture tech info floating around this place is nothing short of STAGGERING!!

[bongobobny]

Yup! And, the pickup coil for ignition timing is a single coil, not two. You are going to have to use the TCI from a 91 - 93, and you will have to change out, or at least modify the ignition harness. You will need a vacuum advance from a newer 2nd gen as well...

[Prairiehammer]

You will need a vacuum advance from a newer 2nd gen as well...

 

Huh? The "vacuum advance", AKA as the "Boost Sensor", or "pressure sensor" is the same on all First Gen Ventures. There is not a need for a Second Gen vacuum advance.

[bongobobny]

OK Kevin, you got me on terminology!! Hey, it uses vacuum and has a variable voltage output corresponding to the amount of vacuum...

 

EDIT:: NOW I see what you are talking about!! My bad, meant MK2 later edition. I was thinking there was a difference with the single coil one but I stand corrected!

[Yammer Dan]

What Bob was referring to was it just requires a different place to hook up the vacuum for the Boost. I think. Right Bongo??

[bongobobny]

Partially Dan, for the '83 the vacuum advance information is 180 degrees out of phase with the '84 up as to what the corresponding TCI uses, due to WHERE the vacuum is monitored. I wasn't sure if the sensor on later MK2 with the single pickup coil was any different, thanks to Kevin, and a little clearer thinking, I know they are the same. It was kinda late last night, I have a chest cold, and my brain is clogged up a little!

 

But Yes, the point being there is a difference between the stock '83 TCI AND where the vacuum is taken from, and the '84 on up, that and the fact the later MK2's have only 1 pickup coil as opposed to two and the TCI's are not compatible between the two, AND the '83 is not compatible with either!!

 

Thanks Dan! And thanks Kevin for setting me straight that the later MK2's used the same sensor.

[Yammer Dan]

Good luck with the cold Bongo. Warden caught it and its not nice. Probally from going with me to Doc's office.