+4mm crank questions

[jamebo]

Hey guys, I should have my other quad payed off in less than a year, at which time I'm planning to do some motor mods to my Shee. I've decided to go with a +4 crank and play/dune porting, but have a few questions about what all is involved with these mods so I know what I'll be needing to do. It's a little in the future, but I want to get an idea of what I'm looking at.

 

My current mods are:

FMF Fatty's

K&N with modded airbox lid. (EHS outerwears lid)

Nosshead with 21cc domes

 

The questions are:

 

1 Can I have the special domes made to avoid the stroker plate alltogether?

 

2 I know I'll need to get another o-ring kit for the Nosshead, but is there a specific gasket kit for this certain type of modding, or does one rebuild gasket kit cover pretty much everything.

 

3 Will my stock carbs be sufficient for this application?

 

4 And lastly, am I leaving anything out that is necessary for the mods I'm wanting to do?

 

I appreciate any info being this will be my first time doing this. I tried to search related topics but It's not working at the moment. Thanks in advance for any input.

[HammerShee99]

Hey guys, I should have my other quad payed off in less than a year, at which time I'm planning to do some motor mods to my Shee. I've decided to go with a +4 crank and play/dune porting, but have a few questions about what all is involved with these mods so I know what I'll be needing to do. It's a little in the future, but I want to get an idea of what I'm looking at.

 

My current mods are:

FMF Fatty's

K&N with modded airbox lid. (EHS outerwears lid)

Nosshead with 21cc domes

 

The questions are:

 

1 Can I have the special domes made to avoid the stroker plate alltogether?

 

2 I know I'll need to get another o-ring kit for the Nosshead, but is there a specific gasket kit for this certain type of modding, or does one rebuild gasket kit cover pretty much everything.

 

3 Will my stock carbs be sufficient for this application?

 

4 And lastly, am I leaving anything out that is necessary for the mods I'm wanting to do?

 

I appreciate any info being this will be my first time doing this. I tried to search related topics but It's not working at the moment. Thanks in advance for any input.

 

1. Yes, you can get milled domes so you won't need a stroker plate.

 

2. All you'll need is a new O-ring kit. That should cover it.

 

3. They should be. Just depends on whether or not you think it has enough power with the stockers.

 

4. I could be wrong here, but I'm told that porting is absolutely critical to bringing the life out of a 4mil motor, and porting couldn't hurt anyway, so that should be on your list of mods, too.

 

I could be wrong on any one of these actually, so if anyone comes along who's more knowledgeable about this than I and thinks differently, I will stand corrected.

[jamebo]

Thanks for the input, HammerShee99. I'm trying to find out everything I can on this beforehand. I plan on a play/dune port to go along with it, should really wake things up with the motor. I've got to get my other quad payed off and then I'll have a little money to work with! It's definitely in the VERY near future!

[Wildcardracing]

Thanks for the input, HammerShee99. I'm trying to find out everything I can on this beforehand. I plan on a play/dune port to go along with it, should really wake things up with the motor. I've got to get my other quad payed off and then I'll have a little money to work with! It's definitely in the VERY near future!

It will be a whole different bike once you go to a ported 4mil. A standard gasket kit will do just fine, you will also need a seal kit and some 1194 threebond sealant because you will be splitting your cases to do the crank. Oh, and a flywheel puller so you can get to the stator plate, which comes off to split the cases.

[dajogejr]

1. Yes, you'll get stroker domes cut. The pistons will travel up into the head 2mm. A LOT of people do this.

2. As answered, yes, standard run of the mill Oring kit for the pro design or noss head will work.

3. Yes and no. Since you mentioned a dune port, my advice would be get a set of 33 or 35PWKs. They will give you more mid and top end than stockers. They are NOT critical, but they would enhance the motor package overall. Same thing could be said for the pipes. They are great trail pipes...but a set of CPIs would be better down the road.

4. You must get the cylinders ported to match the stroker crank's added stroke to make it worth it. You MUST tell whomever is porting them you plan on running cut domes and not a spacer plate. That is important.

 

Ok...it's not that you 100% HAVE to get it ported to run with the stroker crank, it's just that if you're gonna spend the money on the crank, make sure you get it ported to match the crank.

Get the long rod stroker crank, and make sure you get the correct 795 series pistons to compliment them.

[Leadfoot350]

the critical thing about porting is that the guy who ports the cylinder will do it to match the pipes you are running or atleast thats how it should be done. fattys are a ok pipe but some shearer inframes will add maybe another 6-10hp. They are dune friendly too. I have them on my 7mm stock cylinders that are pretty much a drag port. I dune a lot too!!!!!! Cpi's are good I hear but I have never ran then because they cost so much more money.

[jamebo]

Thanks guys I really appreciate all the information. When I start to do this I will contact David Noss and explain what I'm doing and see if he will make the domes, and order the o-ring kit along with them.

 

I've never had portwork done but from what I've read on here the dune port should be what I need. I usually ride in open places with my Shee. I'm probably going to go with F.A.S.T. on it. I've heard alot of good things about them. And I'll let them know about the 4 mil crank.

 

If the stock carbs will do for now I'll probably use them at first, then as money permits get some bigger ones a little down the road.

 

I'll also get some sealant and look into getting a fly-wheel puller. I hope I'll be able to do this on my own, and I plan to try, but if I get a little nervous about it I may look into a builder around this area.

 

One last thing, when I order the long rods kit with the special pistons are the 795 series the ones with the pin moved up 5 mill? I heard that no case mods are required with this set-up, just wanting to make sure.

 

Thanks again guys for all the help.

[jamebo]

the critical thing about porting is that the guy who ports the cylinder will do it to match the pipes you are running or atleast thats how it should be done. fattys are a ok pipe but some shearer inframes will add maybe another 6-10hp. They are dune friendly too. I have them on my 7mm stock cylinders that are pretty much a drag port. I dune a lot too!!!!!! Cpi's are good I hear but I have never ran then because they cost so much more money.

Well I should clarify that I don't actually ride in the dunes (man I wish!, but there aren't any close to where I live) I checked several different builders and they usually describe their ports as woods/dune/drag so I'm just looking for a basic all around application. I have another quad I use for bottom-end woods and trails, and I'm not looking to build a full on drag bike, so I figured the dune port would be the best overall porting.

 

Your right about the pipes, and I didn't realize that the builders matched their ports to them, but I'm probably going to keep my FMF's. I'm partial to them because they were a special Christmas present to me from my wife.

[2bzy2p]

1)yes 2)no 3)no...more then likely once you port your cylinders it would be helpfull to run bigger carbs.I would get rid of the fmfs as well and go with either toomeys or cpis for a dunner or trail/play port.

Edited June 14, 2008 by 2bzy2p