Maximum bore/stroke for a 1200?

[jeffro]

Odds are he thought his was an 1800 since the gen 2's are almost 1800's.

Sean

I explained that very fact to him at purchase, but he said no and he was insistent that it was modified. I'm with you guys on this one I still think he's full of sheet but since I have it apart somewhat, Been cleaning spiderwebs ,grass and waspnests out of it I'll pull the valvecover and check the cams. Any obvious way to check stock vs. aftermaket camshafts? Thanks again,

Jeff

 

[one2dmax]

All aftermarket cams are "weld up" cams. So, look at the edge of the lobe for the fresh layer of metal since it will be a different color. Typically around 1/8" thick.

Sean

 

[Rusty McNeil]

All aftermarket cams are "weld up" cams. So, look at the edge of the lobe for the fresh layer of metal since it will be a different color. Typically around 1/8" thick.

Sean

I think those cores must really make the rounds; the mega cycle cams we bought had some old PCW engraving on one of them...They all miked the same...

 

[RaWarrior]

An engine supposedly that big would need bigger carbs no way it would run worth a damn on the stock ones. If it has the stock carbs chances are it's a stock, or at best mildly modified motor.

People try to BS having built motors in stuff all the time....mainly because it sounds good, and is difficult to verify/disprove. I swear about 99% of Honda 400EX's out there for sale have the 440 kit installed.

 

[wildweasel_pt]

What would you use to measure the expended oil volume? some kind of burette or beaker?

If you use a clear 5/16" hose with a threaded insert for the plug thread with a 5/16" nipple fill the hose completely and oil won't drip due viscosity. Fill the cylinder like i said before and when turning the crank make sure the hose adapter is screwed on the plug thread and hose is full to the tip. As soon as you turn the crank oil will be exiting the hose (valves are closed on compression stroke). Keep turning till no oil exits and starts to revert back to the cylinder (you can check that when you see air getting inside the hose from the exiting tip) That point is TDC. The oil volume that have left is the displacement of that cylinder. Then clean the remaining oil on the cylinder. For measuring you an use any measuring tool. Better to use narrow ones for better accuracy but if you miss by 1cc i don't see that a big problem.

 

[Rusty McNeil]

An engine supposedly that big would need bigger carbs no way it would run worth a damn on the stock ones. If it has the stock carbs chances are it's a stock, or at best mildly modified motor.

Mines running fantastic on the stage 7 Mikuni's. I'm sure there is some HP being left on the table tho.:bang head: I was tapped out on the bike budget and couldn't afford another $2k for carbs.

Smaller carbs are more than capable of supporting proper a/f ratio all the way to top end, the problem is air flow and hp become restricted up there....Driveability is not, if anything undersize carbs will improve general "drive friendly nature"......At the sacrifice of top end HP.

PCW 1500 tourmaster is regularly sold and run with Mkuni/stage 7 and dynos around 165 rwhp in that configuration.

I'm expecting well north of 170 with my setup even with the Mikuni's.....

Now for some flatslides,,,,:biglaugh:

 

[wildweasel_pt]

Are you interested in some FCRs? I have a set of 41s that i want to fit but time is passing by and i have too much stuff on hands

 

[Rusty McNeil]

Are you interested in some FCRs? I have a set of 41s that i want to fit but time is passing by and i have too much stuff on hands

I will be eventually. It'll be the next big thing I do to her.

Right now tho I'm just looking forward to getting my oldest daughter out of college in the spring and trying to get all these medical bills from Ryan's accident taken care of.
Putting my oldest daughter thru away from home college out of pocket with no loans or grants has been quite the task. I could make two house payments a month on what it takes (I live in a cheap house) I'm gonna feel like a lottery winner when that expense goes away.

I AM going to be working 7-10's for the next few months tho', How much you want for them? Is it a whole vmax "kit" with manifolds etc?

Maybe in the spring if they're still around.

 

[wildweasel_pt]

First things first mate. Im refurbishing them along with some other things im taking care of. Im preparing them to fit them to my bike but it might be too much carb for a stock bore engine. Its a inline 4 setup that im modding for the max. I have a template of the vstacks that Sean loaned me for geometry purposes and i'll be machining a set of 4 intake manifolds but i need help from a friend in order to do that and he has been really busy.

 

[jeffro]

If you use a clear 5/16" hose with a threaded insert for the plug thread with a 5/16" nipple fill the hose completely and oil won't drip due viscosity. Fill the cylinder like i said before and when turning the crank make sure the hose adapter is screwed on the plug thread and hose is full to the tip. As soon as you turn the crank oil will be exiting the hose (valves are closed on compression stroke). Keep turning till no oil exits and starts to revert back to the cylinder (you can check that when you see air getting inside the hose from the exiting tip) That point is TDC. The oil volume that have left is the displacement of that cylinder. Then clean the remaining oil on the cylinder. For measuring you an use any measuring tool. Better to use narrow ones for better accuracy but if you miss by 1cc i don't see that a big problem.

Thanks I'll try it...

 

[jeffro]

An engine supposedly that big would need bigger carbs no way it would run worth a damn on the stock ones. If it has the stock carbs chances are it's a stock, or at best mildly modified motor.

People try to BS having built motors in stuff all the time....mainly because it sounds good, and is difficult to verify/disprove. I swear about 99% of Honda 400EX's out there for sale have the 440 kit installed.

Yeah, the carb's are stock ,or they look stock appearing to me.at presant their aren't any other vmaxz around to make a comparison would it help if i took a pic?

 

[Rusty McNeil]

Maybe.

Look for steel head gaskets, they will be pretty obvious plus they'll have some metal tangs sticking out where a normal yammie gasket does not.
(Although a standard PCW 1500 uses yammie gaskets too, at least the two I've seen did)

Engraving on the block and heads, centered dead in the middle up near the cam chain tensioner?

Stage 7 installed, individual filters? Hose to the oil fill location?

Carbs themselves? no way to tell without opening them up.

All the above are just clues, I wouldn't believe any of it without build sheet and matching numbers. If he doesn't have the sheet then he should at least know who he bought it from and put you in touch with them.
If he's hesitant on that then a little skepticism would be in order and the bikes worth only what it would've been worth had engine work not been done. Then you might find later it does have a lot of work and you got a great deal.

Or it has a lot of BAD work and its a screwing.

This is why people like to build their own or at least have it built.

 

[Hopefuldave]

Came upon this thread a bit late, sorry guys...
Interesting, as my Max is going to need a full teardown and rebuild of the motor after a combination of.enthusiasm and stupidity (both mine, all mine!) and a rebore's a definite part of the repairs..
So... While it's apart I might as well go the big-bore route, I'm planning to (and capable to) make up a set of steel cylinder liners and bore the cylinders to match, but unsure of the maximum outer diameter of the liners before I'd*hit the water jacket - is there a magic do-not-exceed? In case it makes a difference, mine's an 88 model, Canadian spec. full-power. If I were to hit the water jacket I imagine there would be Lots Of Problems, not least pressing the liners in straight and getting 'em watertight...

 

[Blurr]

Download Sean spread sheet. Should give you an idea of what you can do. I fall asleep each night going over the numbers. Also spreadsheets are really good for putting you to sleep. Who knew?

click here and download the Engine Builds 'sheet

 

[Hopefuldave]

Thanks, had a look at the spreadsheet, clear as mud! I'll spend an evening and see what I can glean from it...
I may buy a set of damaged cases/barrels to Experiment on - slice 'em up and take some measurements, then tell the family they're Modern Art

 

[Rusty McNeil]

Apparently getting new liners properly seated so they never drop that extra .0005 that makes the head gasket let go is a challenge. I think PCW and many others have had issues with this, perhaps not lately.

Whoever Sean used did a great job on my motor (knock on wood) in the machine work and liner work.

Sean was kind enough to coordinate all the machine work and "hard thinking" and let me have the pleasure of putting it all together.
I can't recommend him highly enough, if you're thinking about doing this at least talk to him and get some advice, he's good.

 

[Rauno Vekkila]

I have debated doing a seriosly big bore on the drag bike but I don't have a cooling system on that bike either. I think the math showed I could get 3000cc's or so with it. BUT, it's not practical.

The largest bore only is 1630 though 1570 leaves more sleeve thickness. The 1500 is far more practical for a street driven bike. We did do a couple of +9mm strokers but suggest +5mm as the biggest I would suggest.

The biggest bore without unshrouding the heads is 83mm (1428cc's) though I have seen (and done) with the stock heads.

We have stroked +2mm with a thicker head gasket on a stock engine/crank/rods. This created a higher compression engine without the cost of bore and pistons. The crank isn't cheap though.

Sean

Hi,

This +2mm stroker sounds interesting. What conrod bearings you have used with this conversion?

 

[one2dmax]

Hi,

This +2mm stroker sounds interesting. What conrod bearings you have used with this conversion?

We still use the stock yamaha bearings. Most of the time it's the Blue's we use regardless of the code that you would use.

 

[Rauno Vekkila]

We still use the stock yamaha bearings. Most of the time it's the Blue's we use regardless of the code that you would use.

Ok, thanks ! I thought that crankpins basic circle is grinded offset (and thinner) and used different bearing method.

 

[one2dmax]

Ok, thanks ! I thought that crankpins basic circle is grinded offset (and thinner) and used different bearing method.

We have the crank welded up and recut to maintain the overall diameter