Topic: Engine swap 500 ---> 550

[winnipeg550guy]

Ok here's my dilemma, Up here in Manitoba, Canada insurance rates are calculated based on engine size and we only have 1 choice for insurance, Provincial government monopoly MPIC.
 I was running a 74' cb550 for awhile ran good shifter seal leak problem was about it. Priorities shifted and could no longer afford to insure my 550, cost approx. $1100.oo cdn per year. Again this is due to engine size brackets used here.
 1-100cc=cheap, 101-500=reasonable, 501and up = Rip off.

 So I decided to look for a cb500 motor to swap into my 550 frame(custom hardtail) which would allow me to insure it at a lower cost approx. $700.oocdn.
 I ended up finding a motor locally only problem was that a complete bike came with it. Just needed clean carbs and fuel tank which I quickly swapped over to it since I was just finishing a carb rebuild, dropped my 550 tank in, fresh gas, VROOOM bike runs fantastic no leaks nothin'
  Easy enough to just swap engine to 550 but I could sure notice the reduced CC's . at the top end.
 Here's my main thought, I'm thinking Big Bore kit 555cc or 605cc kit have a line on a 605 in town bit more $ than the 555 kits, but how big of difference would I really notice between the 2 in the way of performance.I like the high top end speed for the highway and 500cc just doesn't do it, whats and average cost in getting the heads bored etc.

 I'm really unsure if I want to risk disturbing a really good running motor, sure I could have someone do the work for me and set up properly but of course that costs $$.  Have 4 more months of winter before rinding season resumes so times not an issue.
 I'd like to hear the opinions and experiences from others who have gone with a BB kit. on a cb500.
 

[mkramer1121]

Sorry I can't help you on the question, but know that as soon as you start modifying the engines beyond stock, you lose out on the reliability.  BTW, couldn't you just swap the head and jugs from the 550 to the 500 case?  I thought they both used the same lower end....

Oh, and sweet bobber, got any more pics?

[winnipeg550guy]

Thanks, A few more, it's been striped down to bare frame again awaiting engine swap & repaint, picked up clubman style bars and different rear fender/tail light set up.

[TwoTired]

The 550 and 500 lower end are NOT the same in all regards.  Different primary ratio for one thing.

What are you using for drive chain sprockets?  The 500 used 17-34T, the 550 17-37T.  This might explain your loss of top end.

Cheers,

[FunJimmy]

First, you live in Winnipeg and the motorcycle riding season only 6 months.
Second you can’t transfer you motorcycle insurance to your snowmobile for the balance of the year.
So the prorated difference is closer to $200.00 and for that you are considering the use of a smaller and more problematic engine?
Boring a 500 to a 555 is easy enough but the 605cc kit will require larger sleeves and more money.
Add to that the desire to port the head and run a nice cam (you’re there anyway) and the cost continues to rise.
Honda’s CB500 engine has clutch problems that become more acute with the added power of the 555/605 big bore kit.
What do you do and how much does it cost? More money!
Insurance companies don’t usually probe into your engine, but heaven forbid you get caught fraudulently representing yourself when you
need the insurance coverage.

Remember, there are only two kinds of motorcycle riders.
The ones that have crashed and the ones that are going to.
As a surviving member of the latter group, I’m grateful for the insurance coverage I had/have.

Keep the rubber side down!

[winnipeg550guy]

First, you live in Winnipeg and the motorcycle riding season only 6 months.
Second you can’t transfer you motorcycle insurance to your snowmobile for the balance of the year.
So the prorated difference is closer to $200.00 and for that you are considering the use of a smaller and more problematic engine?
Boring a 500 to a 555 is easy enough but the 605cc kit will require larger sleeves and more money.
Add to that the desire to port the head and run a nice cam (you’re there anyway) and the cost continues to rise.
Honda’s CB500 engine has clutch problems that become more acute with the added power of the 555/605 big bore kit.
What do you do and how much does it cost? More money!
Insurance companies don’t usually probe into your engine, but heaven forbid you get caught fraudulently representing yourself when you
need the insurance coverage.

Remember, there are only two kinds of motorcycle riders.
The ones that have crashed and the ones that are going to.
As a surviving member of the latter group, I’m grateful for the insurance coverage I had/have.

Keep the rubber side down!

 Thanks for the reality check, I'll have to check on the insurance transfer idea, have a couple old sleds and 1 is finally running good enough to license. And as far as gears go I've got part under control, I picked up an 18t front sprocket and run the 34t rear when I plan to go for a long cruise but I normally run a 17t - 37t set up in the city.  Big thing for me I guess is reliability nothing worse than breaking down many miles from nowhere with no cell phone.
 I'm not a speed freak just want to lower the rpm's at highway speed and to have a little extra if needed. I sadly realize I could gain a little speed by dropping 30 - 40 spare pounds, at 6-2" 250lbs I feel like I'm on a scooter at times
 I remember the 550 Trans was good ( bit clunky ) and the 500 isn't always easy to find neutral

[chippyfive50]

don't go backwards!!. ...  I went the other way from a 500 to a 550. The 550 is a FAR superior motor, i will third that.
perhaps you could get a 500 frame / tag and register it with the 550 motor, that's where I am.
Sounds like somebody up there doesn't like motorcycles eh. Discourage fuel conservation...??  That is a disturbing expense.
Of course down here in OHIO my historic tag wont expire for another 46 years, and ins is $78.00US

[TwoTired]

And as far as gears go I've got part under control, I picked up an 18t front sprocket and run the 34t rear when I plan to go for a long cruise but I normally run a 17t - 37t set up in the city.  Big thing for me I guess is reliability nothing worse than breaking down many miles from nowhere with no cell phone.
 I'm not a speed freak just want to lower the rpm's at highway speed and to have a little extra if needed.

Sure seems to me you are working at cross purposes.  These engines are Horsepower engines, not torque engines.  They need RPM to make HP.  When you want to scoot, drop a gear or three to get the engine in the HP making band of operation.  Over gearing the engine may make you feel better.  But, it isn't doing the engine any favors.  At higher speeds, the HP requirements go up with the square of the wind resistance.  If you are turning the engine in an RPM band where it does not make enough HP to overcome the HP requirements, you are over geared.  If you can drop a gear and actually achieve a higher top end, you are over geared (sprocketed).  Honda's sprocket selection was not arbitrary.  They went to a great bit of trouble to find optimum sprocket ratios.  What engine mods have you made that changes these optimum ratios?  What rear wheel/ tire size do you use? This factors into the final drive ratio. FYI.

I remember the 550 Trans was good ( bit clunky ) and the 500 isn't always easy to find neutral

This symptom is indicative of a dragging clutch.  This type of issue frequently leads to bent/worn shifter forks and drums as the clutch does not disengage properly.  The clutch in the 500 was based on 350 clutch design, btw.  The 550 revamped the clutch design among other things.  The 550 trans was far less clunky than the 750, unless the clutch was knackered from mis-adjustment, abuse leading to warped steels, or oil selection issues (the fluid is an integral part of clutch operation).

Cheers,

[FunJimmy]

How about keeping the 550 engine and using a bored out 500 cylinder. Tell the insurance company it's a 500 and show the casting marks on the cylinder to confirm it.
Best of both worlds.

[bryanj]

Insurance companies dont normaly like "altered" vehicles in any shape or form and load the premium so that defeats your object

[DarkRider]

what i cant figure out is this...you are going about the more expensive way of doing things...but then again im on an entirely different insurance system here...i think it comes out to not much more then the 500 there for my VF750 and thats a sports model..but anyways...going to all this work to achieve the same effect as having the 550 would be more expensive in the long run then it would be to fix the 550 engine and pay the 550 insurance...or as said...take your 550 engine and drop it into the remaining 500 chassis if you are that worried about insurance.