is fitting an 1100 motor to a 900, worth it?

Posted: Mon May 14, 2007 12:41 pm

as the title says, is it worth it?
what is the difference in power/characteristics?
my bike isn't a standard one, it is a Harris Magnum powered by a 900 aircooled motor. i have seen an 1100 motor for sale, but can't decide it it's worth it or not. i believe my pipes and carbs [mikuni slide carbs, as per GS1000] would probably fit, exterior dimensions and mountings? is that the same?

Posted: Mon May 14, 2007 12:48 pm

Of course it is worth it to put an 1100 motor where that little itty bitty under powered sissy la la 900 motor used to be. Twisted Evil

I do that kind of thing all the time but I put 1100 motors into 750 frames.
900 and 1100 motors mount up the frame in identicle ways, there are no differences in the mounts at all.

Posted: Mon May 14, 2007 12:54 pm

well that's the rub - is the extra 200cc going to very noticeable?
genuine question, i haven't ridden an 1100, there are hardly any of them here. the bike is probably 20kgs+ lighter than a standard 900, so it isn't underpowered by any means, but i always wondered about the upgrade if i ever saw a motor for sale, i have seen a motor for sale....

Posted: Mon May 14, 2007 12:58 pm

markw wrote:

well that's the rub - is the extra 200cc going to very noticeable?
genuine question, i haven't ridden an 1100, there are hardly any of them here. the bike is probably 20kgs+ lighter than a standard 900, so it isn't underpowered by any means, but i always wondered about the upgrade if i ever saw a motor for sale, i have seen a motor for sale....

595 pounds and 86 hp is undewr powered by any standards as far as I am concerned. To pull the front wheel on a CB900F you have to tach it out and dump the clutch because they are so friggin heavy and under powered. My CB1100F when she was still 1062cc, I could roll the throttle and pop the front wheel off the ground. My black CB900F was slow in comparison and has no respect from me since I have built two CB1123 Super Fs with over 125 hp each

Posted: Mon May 14, 2007 12:59 pm

what hp is a standard 1100?

Posted: Mon May 14, 2007 1:04 pm

markw wrote:

what hp is a standard 1100?

108crank but about 98 rear wheel horse power which is what counts.
My bikes are over 125 hp each

Posted: Mon May 14, 2007 2:32 pm

You DO have a Harris Laughing

It'd be very nice with an 1100 engine. Pipes and carbs will fit though you'll have to redo the carb setup to get it jetted right

Upside is a little more power and torque, downside is that you'll have to get some engine rebuild parts from the America's or Europe [DSS do have an 1100F section]

You can equally go big-bore on the 900 to same effect [on performance , if not reliability]

"Is it worth it"...now you have the thought in your head I'm guessing you won't be satisfied until you've tried it

Posted: Mon May 14, 2007 3:43 pm

Your Harris deserves no less. Hit the BIN and pull the wrenches out. You will not regret it one bit.

Posted: Mon May 14, 2007 3:55 pm

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

Posted: Mon May 14, 2007 4:11 pm

It's worth it. The mounts are not allways the same, if you have a frame with solid mounts, then they will be the same. I'm busy with a rubber-mounted 11R engine in a 9F frame.

Posted: Mon May 14, 2007 4:13 pm

pontiacstogo wrote:

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

Hmmm... Now that wasn't very nice. I am sure when you crash you would not like people to poke fun at you.

Maybe I am wrong here and should mind my own business? Confused

Posted: Mon May 14, 2007 4:35 pm

markw this is what my bike looks like she has an 1123f in her and I love every moment on her

Posted: Mon May 14, 2007 4:40 pm

Cb900SS wrote:

pontiacstogo wrote:

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

Hmmm... Now that wasn't very nice. I am sure when you crash you would not like people to poke fun at you.

Maybe I am wrong here and should mind my own business? Confused

Don't get your panties in a bunch - Ray knows me well enough to know when I am messing with him.

Posted: Mon May 14, 2007 4:42 pm

pontiacstogo wrote:

Don't get your panties in a bunch - Ray knows me well enough to know when I am messing with him.

I hear you man... I just hate hearing jokes about people crashing. Sorry. Wink

Posted: Mon May 14, 2007 4:58 pm

Some observations from the drag racing.

The BORE size was the fast decider,stroke meant nothing. The stroke was just "adjusted" by gearing,the short stroke (750) versions just spun faster but the ET was due to the bore size.

Only the 1100 combustion chamber that covers the 70mm bore is the fast shape. Either the 750 or 900 head combustion chamber really resticts anything that looks like "flow".

Bottom line 750 is 62mm bore,900 is 64.5mm bore(only .100" bigger). The stock 1100 is 70mm bore a giant increase in area.

Much more important is the 17mm wrist pin conrods in the 1100. The little 15mm pins in the 750 and 900 are a failure waiting to happen,the rods are really a poor shape really a weak design.

Bottom line is build big. This is not possible on 750 or 900 BECAUSE of the cooling holes in the cylinder. Only the 1100 and 1000C have this desirable solid block since aftermarket "big blocks" have been out of production for 15+ years.

Posted: Mon May 14, 2007 6:54 pm

pontiacstogo wrote:

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

And I crash them good too goddammit Twisted Evil

Posted: Tue May 15, 2007 1:29 am

The 1100 had several things going for it over the 900: a lighter alternator rotor for quicker revs, rods that could actually handle more power, bigger sleeves and bore in a block that could handle it, better head design in several regards, and it actually had cams that made some power. The difference in power between a stock 900 and a stock 1100 is night and day, and the 1100 will handle further mods with less work and without breaking as easilly.

Posted: Tue May 15, 2007 1:53 am

Ray, what is the advantage of an 1100 motor in a 750 frame? I thought that other than rubber engine mounts, all these frames were the same. Thanks.

David

Posted: Tue May 15, 2007 1:57 am

txscbf1100 wrote:

Ray, what is the advantage of an 1100 motor in a 750 frame? I thought that other than rubber engine mounts, all these frames were the same. Thanks.

David

I do not know if the frame tube dimensions are exact between sizes or not but the 750 has the sharpest rake of the three for better handling. I want the solid mount frame and 750 rake. I think the 750 frame weighs less than the 900 or 1100 frames.

Posted: Tue May 15, 2007 1:58 am

fasterspider wrote:

pontiacstogo wrote:

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

And I crash them good too goddammit Twisted Evil

STOP!!!! your F'n killing me here!!!!!!!

Posted: Tue May 15, 2007 2:11 am

crashnfool wrote:

fasterspider wrote:

pontiacstogo wrote:

fasterspider wrote:

I do that kind of thing all the time but I put 1100 motors into 750 frames.

...and then I crash them.

Wink

And I crash them good too goddammit Twisted Evil

STOP!!!! your F'n killing me here!!!!!!!

I have to admit that you do a better job at crashing than I do. Wink

Posted: Tue May 15, 2007 12:49 pm

Midnight wrote:

It's worth it. The mounts are not allways the same, if you have a frame with solid mounts, then they will be the same. I'm busy with a rubber-mounted 11R engine in a 9F frame.

i asked the seller, apparently the mounts on the 1100 motor are the rubber ones - how will this make the transplant difficult?

Posted: Tue May 15, 2007 12:55 pm

markw wrote:

Midnight wrote:

It's worth it. The mounts are not allways the same, if you have a frame with solid mounts, then they will be the same. I'm busy with a rubber-mounted 11R engine in a 9F frame.

i asked the seller, apparently the mounts on the 1100 motor are the rubber ones - how will this make the transplant difficult?

The transplant to a 900 frame from an 1100 frame is too simple, there are no differences in mounting unless you have a solid mount 900 frame. Then you will have to alter the two lower rear motor mounts to make them fit but it is done with a grinder or a hacksaw and is finished in 5 minumtes.
Swapping motors is a breeze and it does not matter what mount is in there, soft or rigid. The hardest part of the job is lifting the motor from one frame to the other because it is so heavy.
Simple motor swaps are fun.

Posted: Tue May 15, 2007 1:00 pm

I just put a rubber mounted 985 engine in my solid mount 750 frame, very easy to put in, just turn the rubber bushings around on the engine so the steel tit points into the mount and it drops right in

Posted: Tue May 15, 2007 3:28 pm

now, my problem is that i am not using a honda frame, my bike is a Harris, and there's no way i'm going to modify the frame any. i will have to look at this motor and see if it will mount up in my frame. all the mountings are solid on a Harris, but the motor mounts up from underneath, it isn't easy, but it's probably easier than the standard frame. this engine is for sale for £375/$750 - with 30000+ miles on it. i think it's alittle expensive - what do you think?