I want to broaden my knowledge

[GLoweVA]

Alright, somebody please school me,
I thought the (78-82) XS11/XJ11 were the only 4 cylinder bikes of the yamaha era, but I just saw a pic of an XJ650 that is also a 4 banger.

What other Yamahas of this time frame (78-84ish) are in-line 4's?

Has anyone looked at wether the header pipes from these other in line 4's will fit or not?

[natemoen]

all the XJ models were 4 cylinders and then the XS11s

[GLoweVA]

all the XJ models were 4 cylinders and then the XS11s

Aren't the xj650s twins?

[GLoweVA]

Oops I supposed I errored there. The xs650s are twins.

[Cuda 69]

xj 650 was a 4 cyl.I had one,they called it a maxim.550's were also 4 cyl.I do believe they made a 750 maxim 4 cyl.too.

[TopCatGr58]

all the XJ models were 4 cylinders and then the XS11s

Right you are Nate, but that statement could make one believe that the XS's came after the XJ's. Yep, after Yamaha's success with the 750 triples and then the XS11's quad, they found success with the 4's and made several smaller engine versions...the 550 and 650 and 750's for 82, 83, but dropped them all in 84 for the FJ 600 and 1100, and the Virago V-twin series!

T.C.

[natemoen]

I see your point TC. I did not mean my phrasing in a chronological time sense, I should have used "also" rather than "then".

[rpgoerlich]

Had quite a few of the XJ's myself.
The XJ650 came in 1980
The XJ550 came in 81
The XJ750 came in 81

[MaximPhil]

In the same time period SECA used the "same" inline 4 as the Maxim.
Phil

[b.walker5]

Right you are Nate, but that statement could make one believe that the XS's came after the XJ's. Yep, after Yamaha's success with the 750 triples and then the XS11's quad, they found success with the 4's and made several smaller engine versions...the 550 and 650 and 750's for 82, 83, but dropped them all in 84 for the FJ 600 and 1100, and the Virago V-twin series!

T.C.

Not quite correct TC. The XJ600/900 went from 83 to 94, then came the Diversion inline 4, and the XJR came along in 90, first in a 400, and then 1200 in 95, and 1300 shortly after until present day. Also in the middle was the YX600 Radian, from 86 until 90, and the FZ. The Radian motor was initially designed for the XJ550, and pretty much all of the above engines are based around the original XS/XJ design, with the only real departure being the XJ diversion series which used an inclined cylinder as apposed to the more vertical design of the others.

[GLoweVA]

Cool. So, the XJ line from 82ish on up are all 4 bangers.
The earlier ones were MAXIMs and also SECAs then came the Diversions and the XJRs.
Whereas, on the later ones, the engines started slanting forward more and the bike transitioned from a cruiser to a sport bike ride.

Basically I was asking to better understand what's out there.
I so much love the in-line 4 on my G and SG and wanted to look for another older yammy cruiser type that was also an inline 4 too.

Thanks guys.

[Schming]

Here's a pic...

...of my '83 XJ750 Mid. Max. , which is a quick, little, good around the town go getter or a one up criuser, but the brakes, dual disc in front and drum and shoes in the rear, are not that great trying to stop a 400 plus lb. bike two up. One good point is the valve shims are the 29mm, so I adjusted both the XS11 and XJ 750 at the same time, allowing me to swap shims between the two

The XJ 750 is the little brother to the XJ 1100.
Although the charging system mimics the Elevens , I do like how Yamaha put the gen/alt up behind the jugs on the XJ 750, making a narrower profile

Day I brought it home





And semi-restored





I did a quick check on the O.D. of the stock down tubes of both the XS11 @ 37.75 mm and XJ 750 @ 37.50 mm , so they're close but I'd have to pull the pipes off of the XJ 750 to see if the head, which I beleive, is smaller than the XS11's

Maybe someone has a head from a XJ 750 in their stash they can measure.

Now I'm curious also, I may just loosen number one on the XJ 750 and test fit the XS11's down pipe

[Schming]

Downtube Comparison

Has anyone looked at wether the header pipes from these other in line 4's will fit or not?

GLoweVA, your query has sparked my interest and curiosity so I did some comparing between my XJ 750 & XS11 downtubes.

XJ 750 on top of XS11



Head side - XJ 750 on top



XJ 750 flange too small for XS11 head



XJ 750 pipe on XS11 head with XS11 flange ( pipe is a little loose radially )



side veiw of XJ 750 pipe on '80G



side veiw of XS11 pipe on '80G



XS11 muffler end



XJ 750 muffler end



XS11 head end



XJ 750 head end



I beleive one could make the XJ pipes work if absolutely necessary but IMHO the smaller pipes will radically inhibit the flow creating higher exhaust valve temps.

I wonder if these would work:

http://www.ebay.com/itm/YAMAHA-FJ110...cd431c&vxp=mtr