650 big bore

[Jspooner]

So I'm fairly new to the XS650 world, I'm into two strokes, specifically RDs and TZs. My dad however is into XSs, He builds about one bike a year in various configurations and always with stock motors for the most part. For his next bike I told him I want to help him build a big motor. I'm looking at going with the 750 kit and cam from Mikes and will probably get the head ported. Any input on this would be appreciated. Also looking for carb suggestions. I have Lectrons on my last RD/TZ that I built, how are these on XSs? Or is there something better for the XS? I've been reading a lot about Dellorto carbs, any input on these would be helpful as well. Thanks in advance.

 

[motormike]

Personally I prefer big bore kits with sleeves and pistons. The big bore jug kits alters the look of the XS engine that I don't care for.
If you want to make serious power... the cranks are suspect and will need weld'n. I've done 3 sleeve kits with slide carbs.. stock cams and never had a crank failure (street use).

 

[Jspooner]

Personally I prefer big bore kits with sleeves and pistons. The big bore jug kits alters the look of the XS engine that I don't care for.
If you want to make serious power... the cranks are suspect and will need weld'n. I've done 3 sleeve kits with slide carbs.. stock cams and never had a crank failure (street use).

Thanks for the input. It will be on a total custom bike so the different look will just add to the creativity of the bike. My dad is going on 80 so I doubt its going to see much abuse but I will keep the welded crank in mind. I was actually considering a phased crank anyway, so that would be an opportunity to weld it.

 

[motormike]

Only know of two fellows who did the phased crank.. and they stated besides the neat " potato potato " rumbling from the pipes... there was no performance improvement. Somewhere on the net there's a site that tells how to install a distributor cap system over the points which would be a nice touch for a chopper. Avoid the " peanut " tank... been done too many times.

 

[Jspooner]

Only know of two fellows who did the phased crank.. and they stated besides the neat " potato potato " rumbling from the pipes... there was no performance improvement. Somewhere on the net there's a site that tells how to install a distributor cap system over the points which would be a nice touch for a chopper. Avoid the " peanut " tank... been done too many times.

That's good to know about the crank. Sounds like a lot of work for basically nothing. Its not gonna be a chopper and no peanut tank.

 

[halfmile]

Before you make any decisions on your motor build talk to Gary Hoos. (Hoos Racing Specialties). He does this for a living and sells only quality products and offers a full service shop.

 

[Jspooner]

Before you make any decisions on your motor build talk to Gary Hoos. (Hoos Racing Specialties). He does this for a living and sells only quality products and offers a full service shop.

Thanks for the tip. I just called him. Lots of trick stuff, also really knows his stuff. Probably a better way to go.

 

[wolds]

Installed Mike's BB kit this year along with Hoos Shell cam and RD springs. Install was straight forward and gave me a nice perf boost. Warren

 

[Jspooner]

Installed Mike's BB kit this year along with Hoos Shell cam and RD springs. Install was straight forward and gave me a nice perf boost. Warren

That's good to know. After spending some time talking to Gary Hoos yesterday I am leaning towards going with him for everything. Mainly because there's someone there to talk to and that can answer questions.