spurdy

The connecting rod between the web is moved outward by 2mm. This changes the top dead center by 2mm as well as the bottom dead center by 2mm giving you 4mm of increased stroke. However far you move the piston at the top position is also done at the bottom position. Therefore no spacer plate is needed unless you increase the rod length as well. Please correct me if I am wrong, but I think I have this correct.

You can use stock pistons with a 4 mill crank if it isn't a long rod crank. Then all you have to do is run cut domes. You should only have to run 795 pistons and cut domes if your crank is 4 mill and long rod. I am pretty sure this is correct, and I believe this is what Kevin runs in his bike and offers as a 4 mill set up.

Same thing happened to me. Coil tested bad. It is hard to check the coil accurately without it being under a load. I bought a coil and still no worky. Checked the stator and it tested good, however, I did find a broken wire in the harness. Now I have a spare coil and that is what I use to test with to see if my original coil is bad!

I have a Pro Design Cool Head and just picked up a Modquad Cool Head off of ebay. Does anyone know if one or the other offers better cooling properties? I am building a 4 mil stroker and a stock stroke motor and would put the better head on the 4 mil if there is a difference. I am also running an oversized radiator with engine ice and a couple of cooling fins on the lines. I figured with the oversized radiator and the engine ice either head would do just fine. I also picked up a temperature probe from CRJ Performance. I built the last one I had, and I must say this new one is pretty cool. The thermocouple is housed in an inline aluminum body to splice into the return line and is connected to a 3/4" digital read out that clamps onto the handle bar. Pretty slick looking unit and easy to read while riding (unlike the thermometer style I have seen). What is a typical operating temperture range? More importantly, where would the redline be? Thanks guys!

I had a motion pro twist on my last bike and loved it. Took a little getting used too at first, but after that it was great. However, everyone else that got on it hated it (I thought that was cool too!). Currently running with a thumb throttle and it is OK. Debating on changing. Never had any mechanical problems with carb adjustment or engine trouble though. Same principle, moving a cable to open the slides.

I had a mild dune port with trinity stage 4 pipes and ran 35 pwks and hated them (hated trinity as well). They were too big and flooded too much fuel for the port job. Low bottom end but once it came on the pipe it was hellish. Too much like a light switch though. Dropped to 33 pwks and she was a totally different animal. That was a couple of bikes ago. Now running 34 mikuni flatslides and not looking to change. So far happy with them on a mild dune port. Upgrading to 4mil stroker with a play port and current CPIs (winter project) and haven't run the 34s yet with them yet. Hope they run as well but will go bigger if needed.

Sounds like coolant leaking into the cylinder. This should only happen at the jug i.e. head gasket, spacer gasket, crankcase gasket. Impellar can only leak into tranny and would not emit smoke from exhaust. Only thing that sounds amiss is "dark smoke"??? Water (with anitfreeze) is usually white. I hear "no spacer plate and cut domes" is the way to go! SP

Don't sand blast them unless you plan on finishing them. It will leave a rough finish as well. I did that to a head that I painted and sold on ebay. Looked great with paint. I also sand blasted my cases and jugs prior to painting from an automotive shop. Worked really well and was super easy to clean up. I wouldn't polish them because they require so much work to maintain (but that's just me, they look good polished, just alot of work). I would post a picture of it but I don't know how to reduce the size of the file. It held up really well to the abuse and the temp it was subjected to. Debating on whether to do my next motor the same or go with powder coating. SP

Oh shit! My bad. Guess I should look closer. Just got caught up in the "conversation"! Thanks for pointing it out. :ohmy:

Holyman. I have just tore down my engine to build a stroker. I have a good crank that is stock stroke. Trued and welded. 1.53mm small end play on one side and 1.56mm on the other. 0.55mm distance on the large end. Don't know what the shaft run out is due to lack of a dial indicator. Was going to build another motor with it and sell it on ebay but would part out the things I have if it worked better for me. Make me an offer. SP

Thanks again! Yeah, cases split, cleaned, sand blasted, cleaned again (boy is it a bitch to get all the sand out!), taped and ready for paint. Just need to figure out if I want the additional headache of the +4mm stroker or go back with stock stroke. I think either way I want to go with a new crank, so I figure might as well stroke it. I am the only one I ride with that runs a banshee and have only dealt with stock strokes up till now. With no one else around that runs one I am left on my own to choose. I guess I'll talk to Jeff and run my set up by him and see what he thinks. Thanks again for the advice! :smile:

Thanks! I just got off the phone with the local shop. They haven't ordered anything yet. I am picking my stuff back up from them and going another direction. I just tried to call Jeff and their shop is closed this weekend. I checked out his web site and his prices seem really reasonable! I don't mind spending the money as long as I get what I pay for. I suppose he will just have to look at my jugs and see if they can be reused for a stroker crank. I have a buddy that has a virgin set that I could pick up at a good price if I need them. A new set of stroker domes probably would be the way to go. I was surprised to hear that the work is done on the squish side! I figured the dome would just be recessed in the head farther. You mentioned having the bottom end done. I thought the only time the bottom end needed work was with a 10mm stroker? I've just split the cases and have them ready to go to the paint shop. If there is work to be done to them I don't want them painted first! Thanks for the input!

OK. Now I am getting a little concerned :ermm: . I am in the middle of a rebuild. Cases sprung an air leak and ran lean damaging the pistons and requiring bored and honed. I took it to a local shop that has done decent cylinder work for me before. I was discussing with them going to a 4mm stroker crank (my current crank is in good shape just showing some small end play close to service limits and is trued and welded). The jugs are already ported and we discussed the spacer plate and no spacer plate. We decided Hot Rods H129 crank with 795 pistons. He talked like this would be drop in and go. He didn't say anything about changing the porting or machine work to the domes (I am running a Pro Design Cool Head with 17cc domes). If they don't know what they are talking about I think I'll just take my parts and run. I trust them to do the bore and hone but, I am a little worried that this stroker might be over their head. Strange, because they have a really good rep around here. So, adding the +4mm crank to an already ported jug is going to require what? How do you recess the dome in the head? Remove material from the back side of the flange of the dome or remove material from the mount surface of the head? Any comments are appreciated. Thanks!

I thought if you ran 795 pistons you didn't have to cut the domes? Doesn't the wrist pin location take care of the piston travel issue?

I had a similar problem. I could tell on mine that I had one cylinder that didn't fire the same as the other. It ended up being a reed valve problem. The higher the RPM the better it ran. Low RPMs sucked. Once I got into higher gears i could keep the RPMs up to enough to run. I was running reed spacers to clear the clutch actuator arm. The v-force reed was falling out of the frame into the spacer which made it run like shit. Simply changing the location of the spacer to the other side of the reed cage frame was the solution. Don't know if this is your issue or not, but, if the reed valve does not "flutter" it does not perform its intended function. Good luck!

My thoughts exactly. +8 degrees sounds like too much timing to me. Not that this is the sole cause of the issue but possibly a contributing factor. Just my $0.02 worth.

I've seen this one before and got a laugh out of it.....He said boost bottle

Why WOT???? Compression is the same with or without fuel isn't it? Well.. maybe not....Is this the reason?

Where was it going to go through to? The crankshaft case is an airtight chamber (with the jugs on). This oil you put in there has no place to go and you sure don't want to put it together like that. What would happen to the oil. If it did start your crank has to slop through it every rev. and it would get into the cyl. I suppose worst case is you get allot into the cyl. and oil won't compress like air and fuel and it could cause a connecting rod to break. Probably unlikely but worst case. Best thing is don't get any sand or crap in it!

I don't think I have ever seen PWK's intergrated with TORS. Are you sure???

I am with Rare....What are you talking about???? Nothing that could have fallen in there will float in oil.....And if you did fill the crankshaft case with oil you can't leave it in there....This is where your air fuel mixture is pulled to before it goes into the cylinder....

What o-rings are you going to replace if you have a head gasket? I would say, based on the limited info given that you overfilled the tranny. Are you sure it is the tranny tube pissing?

I ride in the rain and water with K&Ns w/outerwears and no problems. No airbox at all. Gotta be fat though, more air, more fuel and oil!

Thanks, any other takers?

This is crude but it sounds like you're running out of options. If no access to a tig welder maybe try to smack the center with a steel hammer forcing the allen (or what was) to close up again. Now, drive, I think it is an M6, allen wrench 3/8 drive into the socket. You'll need and hammer driven impact driver at this point and your only going to get a couple of shots since the metal is already weakened, but smack the impact driver with a heavy dead blow and cross your fingers, if your lucky it will budge. Once it is moving yoiu could go back to the chisel method or whatever suits your fancy. Good luck!