'84 1200 engine for a '82 GW

[canuckxxxx]

ekvh » Thu Jul 30, 2015 5:08 am[/url]":2ynpv4ah]
Not sure, but I think the 1200 uses a combination of which gear you are in and vacuum to adjust timing via a black box. I think it had a few more degrees advance available this way.

Hmm, I'm using the 1100 ignition so I wouldn't get any extra advance. But the 1200 manual shows how to check timing so I'll follow that :read: and see what happens. Maybe 1100 timing is different that 1200. :headscratch:

Will report results :whip:
Brian

 

[slabghost]

ekvh » Thu Jul 30, 2015 7:08 am[/url]":3czaln7g]
Not sure, but I think the 1200 uses a combination of which gear you are in and vacuum to adjust timing via a black box. I think it had a few more degrees advance available this way.

Yes full advance on the 1200 is 45 degrees.

 

[slabghost]

Could just use contact adhesive or whatever and some cellophane or plastic wrap to cover the hole.

 

[joedrum]

lets make this clear ...the most important time about a motor is fire time that when the spark can make a motor come alive .... if this is off it matters not how good everything else is timed .... so fire time is the boss and main player in this thread

 

[joedrum]

also brian i have a motor in a 82 1100 running set up just like yours ...but it has never pushed a wheel yet ... so your motor is further along than mine as it has ran no load only so far ....the timing on 1100 and the use of 1100 heads and cam should make this jell .....

so it seems first thing to do is see if cranks are pinned in the same spot ...if so this should make iggys the same on both motors ..seems degree wheel you have will do that ...to find where its firing with light or something .....

you can also just run it like i did and play with advancing or retarding ignition with the vac advance canister is what i did .... been long time ..so cant remember much ....but it was doing this that got the motor running good as i remember but on mine the motor still has 1200 heads and cam so how this info applys to yours is another story also ... im sure your close to getting it ...

 

[canuckxxxx]

The ignition timing check for the 1100 is the same as for 1200 :read: ; with engine idling the "F-1" marks should line up with the marks on the case. But the "F-1" marks might be in a different spot on the 1200 flywheel than the 1100...so we shall see. :builder:

Later 1200s the ignition works off the crank at the front (or is it the cam wheels) so it will be a whole different setup.

Brian

 

[slabghost]

I'm betting ignition is off 10 degrees or more.

 

[joedrum]

the flywheel marks are different ..i could never figure out some of the marks on 1200 cranks ...but never dug deep just went on to trying to run it

 

[canuckxxxx]

OK, first of all I blew it on the gas mileage check. Filled up with gas and, for some reason, I reset the trip meter without noting what it was at :head bang:

Did compression test.

1. 150
2. 152
3. 148
4. 150

I glued the piece of lexan on so will just wait till that dries before I check ignition.

Brian

 

[joedrum]

gee getting milage complete ..has always been tough for me ..im always dropping the ball somewhere in the proccess

 

[canuckxxxx]

I checked the ignition timing with my timing light but it didn't turn up anything that would reduce performance. In fact the ignition was advance a bit due to the vacuum advance. When I first checked it I couldn't see F-1 at all but that was because it was idling a bit too high. I slowed it way down and the F-1 appeared at the top of the site glass but above the marks on the case. Disconnected the vacuum advance and plugged the hole in the carb and it went down to lining up with the marks. Revved it up and F-1 went up past the top of the window so centrifugal advance is working.

Brian

 

[dan filipi]

canuckxxxx » 27 minutes ago[/url]":dr3po509]
I checked the ignition timing with my timing light but it didn't turn up anything that would reduce performance. In fact the ignition was advance a bit due to the vacuum advance. When I first checked it I couldn't see F-1 at all but that was because it was idling a bit too high. I slowed it way down and the F-1 appeared at the top of the site glass but above the marks on the case. Disconnected the vacuum advance and plugged the hole in the carb and it went down to lining up with the marks. Revved it up and F-1 went up past the top of the window so centrifugal advance is working.

Brian

Seems like it might be good then?

You could also use the timing light on the cam marks.
I did this a while back just to verify it was advancing but might be able to see how much?

 

[joedrum]

hmmm brian so your saying the bike seems to lack power and your thinking rings are bad .. and this is with 1100 heads ans cams and iggy ...hmmmm...and it seems the comparison is the 1100 motor you replaced and was carb the same way .....you have been all over this motor and it seems to me your doing everything right ...

it seems as though maybe the 1100 cam might be a little narrow in its spread to cover the rpm zone good ...meaning the duration on open time of valves is to short maybe ... as it seems the early 1000 cams have duration long enough to contact piston ...it could be said from your figures that the 1000 cam put right by marks may have timing retarded enough to cause piston hit ...but not so on 1100 cams...this might be huge factor ..at this point there no comparing the two set ups one hits and wont work ..and the other 1100 cam motor will work here .... this might be why hooch runs different and has no bad spots ..of course this is after piston knoching ....im sure there is something we might be missing here but at moment i dont know what it is ... you really went after the numbers and it seems to me a good job of it ... :headscratch:

 

[canuckxxxx]

I think this 1200 has a bit more torque than the 1100 just because of the way it handles the tall top gear. Don't think the 1100 would have liked that. And with valve timing at 5 BTDC it has as good, if not better, top end rush.

Something that you mentioned, Joe, in the very first post of "the story of Hooch" is that you put the 1100 exhaust on and it completely killed performance. Seems like I read somewhere that the 1200 exhaust has better flow than 1100.

Then, of course, there are the 1200 heads and cams that are designed for more charge velocity which is supposed to boost performance. Also the 1200 head combustion chambers have more squish area which would match up with the 1200 piston tops.

So still some things to check out.

Brian

 

[Denver]

Lots to read since my last post. :read: Whats the old saying, timing isn't everything, its the ONLY thing? :headscratch: AS far as buffeting, stock wind shield has much more than Tulsa's does. :yes: Set mine to look through, & not over, but got mine a little taller than their standard height if memory serves, sheds water like a duck. :rocks: Over your head, just like the wind, you stay dry if you move faster than the wind, & rain, at your back while traveling. :smilie_happy:

 

[slabghost]

Check the vac advance port on the carb. It should be one that vacuum increases with throttle and is low at idle. It's possible you have one that is reversed.

 

[ekvh]

Good suggestion, slabghost. That would explain a lot and save re-ringing and complete tear down. When I first advanced my cams, mine was the same, dying out at 6500-7000, but advancing ignition took care of it. I am trying to shift at lower rpm, but it still feels like it's pulling hard at 8k.

 

[joedrum]

well i really dont get it .....ok id say the squish area on 1200 heads is just like the rest of the differences in the 1200 head verses 1000 or 1100 ....1200 cam is mild ..the intake valve is smaller ...and squish area is smaller to match to get good compression ...honda never got off the bringing the torque down lower in the rpm ... i didn't work in 78 1000 or any year after that ...to me they missed the whole ball game on low end torque playing with cams,heads and valves ... when its been proven to me its the cv carbs that kill the low end ... the earlyest 1000 carbs didn't even have a accelerator pump to help ... to be quite honest its hard for me to beleave they made it this way as final decision for production ... so to me none of the cams after 77yr have the numbers to cover rpm zone oldwings are capable of ...you just dont put mild cams and flow design in a high rpm motor and call this good engineering to me ...

personally the honda numbers mean nothing to me .. as they dont apply to my bike what so ever ... so what right and where to me is not a concrete issue ....the right cam timing is really just unknown .....it seems with my bike and carb dial in im just not having bad spots anywhere ...if there is ..its at idle .. but from just off idle there is not much to do but hang on ...its not the gearing ..ive had them all mostly and with the 1200 gearing ..hooch is still a rocket hunter ....

i seem to be in a good spot ... my single set up has no heat ....dosn't have any bad spots from idle to red line ....plugs look good ....so im having a hard time relating to all this so so running of this build and others close to like mine .....all the things talked about in this thread are quite small really even at 8 or 9 degrees ...sheesh the stock ignitions and dyna can fluctuate that much as normal ....so i think there is other factors going on here ... with eric i think its carbs and with brian id say it is carb too ... not being critical just opening the window some as i think the timing thing is getting to much credit as the only culprit....... opcorn:

 

[dan filipi]

+1, and well said Joe!

 

[canuckxxxx]

Well, Joe, if you stand back and look at it; I've replaced a tired 1100 with an even more tired 1200. It has the same heads, ignition, carb, and exhaust in the same bike. But 100cc bigger which is probably cancelled by the dismal compression. So how could we expect it to have way more power. :nea: :doh: oh2:

Brian