PMA (kick only) + Rephase + Big Bore = Practical? (Cheney rigid project).

[Jeeter]

So, I've been doing the research on the engine. So far it looks like:

- PMA (kick only .. uh ... I think, I hope I'm up to kickstarting it).
- Rephasing.
- 750cc.

As well as the obvious such as Mikuni round slides, Pamco ignition kit, Ascot-style right-side-exit 2:1 pipes with some sort of Supertrapp on the end of it, other niceties like oil cooler, bla bla.

To me this configuration seems highly appropriate given the nature of the bike. I'm a little unsure about the kick-only decision, however even at my towering height of 5'6" and weighing in at an Army-Tank solidness of about 170 pounds soakin' wet I had no troubles kicking over my 1978 TT500. It's all a matter of technique and knowing how to feel what timing position the engine is in with your leg (I didn't need to use the sight glass after owning it for about a week). Just set up the engine, ratchet the kicker all the way up, and put some ass into it. Vroom every time. I'm hoping the XS650 will be a similar experience. I don't know what static compression I'll be running yet but I am hoping I'll be ok to start it if the compression is no higher than about 9.5:1 or so.

My TT was an actual TT, not an XT. So it had no provisions for lights. I had the dealer install a Preston Petty lighting kit on the TT to make it street-legal-ish. All the same drawbacks such as no lights when the engine isn't running, headlight flicker at idle, and a faked brake light (I had to turn on the headlight during the daytime to pretend I had a brakelight if the po-po was behind me). The idea of that dirt-simple setup like that for THIS bike appeals to me.

Ok, so how practical is all of this? Just to say it, I'm not concerned with turn signals (not required here, hand signals are fine). I plan on running only a tach and oil pressure guages, so minimal electrical issues there. Are there prefered PMA setups?

Oh and also are the Mikes big bore barrel kits made by Heiden Tuning? They sure look like Heiden stuff.

Any help on these ideas would be - um - helpful (I'm such an imaginative writer geez!).

PICS: Almost forgot. where can I locate various machined/deeply finned access covers like these on this engine/bike? This bike is a project belonging to a forum member, I got the pics from the gallery. Thank you.

 

[Jeeter]

By the way, I've seen this and a couple of others like it. Just so you know what I've been exposed to so far. (Sorry about the botched video attachment, even though I tried two different ways I can't seem to get the video to embed so you'll have to click on the link instead of viewing it here. It's just a Hugh's Handbuilt demonstration of his PMA setup).

 

[TwoManyXS1Bs]

Hi Jeeter! Just edit your post #2 and remove the redundant "http-youtube-watch-v=" part of your video URL. Then do a 'preview post', and see if that works for you...

 

[hotdog]

are the Mikes big bore barrel kits made by Heiden Tuning? - Yes they are..

The Heiden/Mikes/650Central big bore kit is a reproduction of the original VAM sidecarcross cylinders - see them here

Personally if you want a performance motor - I would stay away from the Heiden/Mikes big bore kit, there are far nicer piston assemblys available for the application i.e. - J.E., Venolia, Wiseco, Wossner, Ross...

 

[Jeeter]

Hi Jeeter! Just edit your post #2 and remove the redundant "http-youtube-watch-v=" part of your video URL. Then do a 'preview post', and see if that works for you...

Thanks, I'm usually a little more forum savvy than this. Must be age. Thanks again.

 

[Jeeter]

are the Mikes big bore barrel kits made by Heiden Tuning? - Yes they are..

The Heiden/Mikes/650Central big bore kit is a reproduction of the original VAM sidecarcross cylinders - see them here

Personally if you want a performance motor - I would stay away from the Heiden/Mikes big bore kit, there are far nicer piston assemblys available for the application i.e. - J.E., Venolia, Wiseco, Wossner, Ross...

I'd read some negative stuff on the Heiden barrel kits, but I wrote that off as a possible fluke.

I'll look into those other kits that you suggested. I'd prefer Wiseco piston kits mainly due to familiarity with them (however I am open to suggestions of something other than Wiseco). And the barrel kit interests me for not only the obvious reasons (greater power) but also the enlarged fins would be an asset in my area (low desert). The greater fin area along with an oil cooler are both good ideas for an air cooled bike around here. At least one would think so.

The rephase is for a couple of reasons. I've been made to understand that they vibrate less, and that the XS650 has a reputation for that numbing buzz in the wrists at freeway speeds. Ok, yea, see I really can live without buzzing hands, I've had bikes that gave me the buzzies for hours and I was hatin' life for a while. And that was in my 20's, now in my 50's I'm less willing to put up with that type of vibration if I can get away with it. So, if the stars align (money, practicality, and so on) then the rephase is on the list. And of course there is the "Ooo .... Ahhh" trick factor that guys like me tend to find appealing.

Also, is the XS650 any more difficult to kickstart than the TT500? Still deciding on whether or not to go PMA w/kick only or electric start with lithium/ion batt.

Not building an all-out race engine here. I may even start with a running engine on this project, and then build up a bad-ass engine on the bench while I'm riding the running stocker. It all depends on how things fall together over time. Right now I am attempting to educate myself on the nuances of the XS650 engine and the industry that is built around it. All this stuff that is old-hat to most members here is all brand new to me, so I'm trying to learn as much as possible while not wearing out my welcome around here.

It can be tough to do, especially for people that are question askers. Y'know the type, it's that one person that raised their hand in class with "yet another damned question" after the teacher had already said "If there aren't any more questions you are all dismissed". That one kid would raise his/her hand with a question, and the entire class would let out a collective groan because that kid was holding up the rest of the class from being dismissed for the day. Y'know, that kid? Well, I'm afraid that's me.

Once I learn my footing with the engine I'll be less of an annoyance. I'm just crash-coursing this engine. Come to think of it I don't know why, I mean it's not like I'm even to that point anyhow, I have framework concerns to get finished up first. I guess I'm keeping my mind busy, I have an 8mm kidney stone in me right now and an 18 inch long stent between my kidney and my bladder. I have to have that audio blast procedure done at some point soon (dealing with the VA, these things can take time with them). My sleep patterns are all messed up and the pain is kinda brutal. So I think maybe these engine concerns are conversational distractions for me.

What I really need to be working on is the front end dimensions and getting Spitfire and Cheney working together on the frame/fork package.

Wow, blabbing. Seriously.

Ok, so I'll check into those other engine kit companies. Thanks Hotdog.

 

[TwoManyXS1Bs]

Jeeter, you need more calcium in your diet.

If you can get your hands on one, the Australian hi-ratio primary gears should reduce kickstart effort tremendously. The threads/posts are in here somewhere...

 

[retiredgentleman]

If you want to spend a lot of money then, go with PMA, rephase and 750 cc engine. In my personal opinion, I don't see any value added for any of those. A rephase engine is not going to magically reduce vibration.

I use the stock alternator, stock 360 degree engine and stock 650 cc size engine. My engine is tuned correctly, so there is very little vibration at highway speeds. I have no trouble going 400 kms per day on 5 days trips into the mountains.

I recommend you stay with electric starter motor. Kick starting is more for the under 45 crowd. There's no need for an oil pressure gauge on these bikes. They run with very low oil pressure anyway. Just warm the engine up before driving off, as this thins the cold oil and prevents damaging the sump strainer.

Instead of an oil pressure gauge, install a voltmeter. The voltmeter is much more useful.

A pamco ignition is an excellent way to go.

An oil cooler would be a good thing in Arizona, not needed here in Canada.

 

[arcticXS]

Hotdog,
With my 750 kit from Jerry Heiden, I got Wossner pistons. Maybe different vendors supply different pistons.

 

[scabber]

I would keep the electric start. No way I will use the kickstart. At 9.5 compression 195 LBS on a compression gage no kicking for me.

 

[Jeeter]

If you want to spend a lot of money then, go with PMA, rephase and 750 cc engine. In my personal opinion, I don't see any value added for any of those. A rephase engine is not going to magically reduce vibration.

I don't want to spend alot of money, anyone sane doesn't. I want a well constructed, well thought out motorcycle (um, hence the participation in this forum). Odd, seems more than a few rephaser users have mentioned a change in vibration at freeway rpm, "less buzzy". I know my last two Harleys were that way, at 70mph they shook like paintshakers. At 73mph all was well with the Earth. I'd be interested to know how rephasing the engine will not affect the vibration of the engine at a given rpm. I'm always open to learning.

I use the stock alternator, stock 360 degree engine and stock 650 cc size engine. My engine is tuned correctly, so there is very little vibration at highway speeds. I have no trouble going 400 kms per day on 5 days trips into the mountains.

I'm not sure how state of tune has anything to do with mechanical balance. I'd like to learn more please.

I recommend you stay with electric starter motor. Kick starting is more for the under 45 crowd. There's no need for an oil pressure gauge on these bikes. They run with very low oil pressure anyway. Just warm the engine up before driving off, as this thins the cold oil and prevents damaging the sump strainer.
Instead of an oil pressure gauge, install a voltmeter. The voltmeter is much more useful.
A pamco ignition is an excellent way to go. An oil cooler would be a good thing in Arizona, not needed here in Canada.

Thanks for the helpful info on the oil pressure guage. Oil cooler is a must in these parts on air cooled engines. The Pamco seems like the prefered stuffs. Clearly more research is needed on the kick-only issue.

 

[Jeeter]

I would keep the electric start. No way I will use the kickstart. At 9.5 compression 195 LBS on a compression gage no kicking for me.

Hmm, I'll need to think it over. My dad's last Brit bike was a Triumph 500 kick only and I had little trouble stomping that crap-fest of a bike to life (damned high-strung Triumph and those Amal carbs! ARG!). And as I've said the TT500 was candy once I got used to the technique.

So while I am open to the suggestions of folks and opinions of those that wish to help, I think it would be beneficial to hear from owners that actually have kick-only XS650s. I mean, doesn't that seem resonable?

I'm not ~set~ on kick only, but I am interested in it enough to research it's viability. Same for the rephase as well as the enlarged fin big bore cylinders, it's all on the table but can be removed from consideration just as easily.

Thanks!

 

[Jeeter]

Hotdog,
With my 750 kit from Jerry Heiden, I got Wossner pistons. Maybe different vendors supply different pistons.

So is it just the pistons that come with the Heiden kit that are less than desireable? If so, why can't just the cylinders be obtained separately and used with a Wiseco piston kit?

 

[troopthrowback]

As far as vibration goes my 1978 xs650 (stock everything except dual sport tires) shakes so much less than my rigid 1966 Triumph 650 that I can't even believe they're both 650cc 360 crank parallel twins. And that's at all speeds up to about 85. Above that (I've only gotten the Yambler up to about 90 and the Triumph's been clocked at 118) they're comparable = both suck but it's worth it...)

I run the stock style rubber handlebar bushings in both (yes, the Triumph pioneered the concept, but it's bushings are only 1/2' thick as opposed to the Yamaha's 1" +) and the footpeg bushings on the Yamaha (Not part of Edward Turner's design for the Triumph). I believe these help tremendously, as does the short stroke motor of the Yamaha.

 

[troopthrowback]

And of course, both bikes are kick only. The Triumph compression ratio is 9:1 as opposed to the lighter Yamaha's stock 8.5:1. That and the Triumph's been rebuilt, the Yamaha is tired. It's surprising to me how easy the Yamaha is to start. It iften fires on the first piston comression stroke, giving the "falling away" feeling at the kick lever as opposed to the second compression stroke of the Triumph (like the Harley you're used to).

 

[retiredgentleman]

Yes, these bikes are very easy to kick start. But I'm lazy, and I much prefer electric start.

Last year, someone on the forum here, asked how my bike was to kick start. I said "I don't know, I never use it, as the electric starter works perfect everyday". So, after going for 6 years without kick starting, I gave it a kick, on a cold engine, and it started right up easily.

I suggest you leave the starter motor and starter relay in place for the first riding season. Use only the kick starter for the first season, and see how you like it. If you like it, you can then remove the starter motor and save 6 lbs weight.

 

[XSLeo]

On the engine tuning, a properly tuned engine both cylinders pull the same from idle to WOT. This is mostly in the carbs. They need to be properly in sync.
When both cylinders pull the same the engine runs smooth.
If the cylinders pull differently, they fight each other. This causes more vibration.
I have Mike's 750 kit on my 75. The vibes on it are much different on a stock engine. On my 75 the vibes at low rpms, under 3500 are slightly more than stock. At higher rpms where the stock engine tend to get an increase in vibes, above 4000 rpms, Quite an increase on some, my 750 doesn't get more vibes. It's as smooth at the high rpms as it is at low.
I think the difference in the piston weight makes the difference.
As far as a kick only, I don't think so. As mentioned the 9.5 compression and 195 psi is a bit stiff. When you stall it at an intersection, it's much easier to pull in the clutch and push the button to start then fumble to find neutral and kick start it.
The extra weight of the starter and battery may lose a racer a few seconds per lap but on the street you hardly notice the weight.
I can't speak much on the rephrase, I don't have one yet, But a bit of searching and you will find a ton of info on it from Hugh, of Hugh's Hand Built, he's done a bunch of them.
Leo

 

[mrriggs]

So while I am open to the suggestions of folks and opinions of those that wish to help, I think it would be beneficial to hear from owners that actually have kick-only XS650s. I mean, doesn't that seem resonable?

I'm not ~set~ on kick only, but I am interested in it enough to research it's viability. Same for the rephase as well as the enlarged fin big bore cylinders, it's all on the table but can be removed from consideration just as easily.

Thanks!

My daily rider is a kick-only XS and I've never, even once, wished that it had electric start. They are easy to kick and, if tuned right, will always fire on the first or second kick. I do not have a big bore or high compression so your mileage may vary.

I also have run a 277 re-phase and found it far more "buzzy" than the 360 when going down the road. The 360 crank I'm running now is smooth by comparison. That's not to say that it is actually smooth, because there is no way to make a non-counterbalanced parallel twin run smooth. To me, the 360 has a rhythmic vibration where the 277 had a harsh buzzy vibration. That said, I still prefer a 277 motor to a 360 just because it sounds better.

I have never run big-fin jugs and I've never had the motor overheat. So, it's kind of like the solution to a problem that doesn't exist. I also don't live in the desert so, again, your mileage may vary.

 

[TwoManyXS1Bs]

...Last year, someone on the forum here, asked how my bike was to kick start. I said "I don't know, I never use it, as the electric starter works perfect everyday". So, after going for 6 years without kick starting, I gave it a kick, on a cold engine, and it started right up easily...

RG, that may have been in one of our discussion threads on the 'enhanced retard' feature of the new Pamco electronic advance box. Supposedly, that new unit retards the ignition timing to near TDC at starting speed, and we were curious about how well that was working for the kickstart folks.

 

[Jeeter]

RG, that may have been in one of our discussion threads on the 'enhanced retard' feature of the new Pamco electronic advance box. Supposedly, that new unit retards the ignition timing to near TDC at starting speed, and we were curious about how well that was working for the kickstart folks.

WOW! I too have the "enhanced retard feature" ... um .. wait.