Mike's XS new 750cc kit

midnrider · Posted: February 2, 2008, 1:09 am Post subject: Mike's XS new 750cc kit

I just ordered one of Mike's new 750 kits...can't wait for it too arrive...anyone else onboard for this great (or at least seems to be) new XS product from our good friend Mike?
Very Happy

mo650chopper · Posted: February 2, 2008, 9:48 am Post subject: Re: Mike's XS new 750cc kit

I'm not quite ready to tear into my motor that far Sad

If I was I would be buying that kit now as well. That's a nice price. I like the additional cooling fin area.

I'm waiting until my motor starting to wear out enough, or breaks to justify a rebuild. Then maybe a re-phased 750 will be created. Let us know how it goes.

royfisk · Posted: February 2, 2008, 12:08 pm Post subject: Re: Mike's XS new 750cc kit

I like the sounds of it but wouldnt use it because of the fin area. DOESNT MEET Vintage Road racing requirement that you cant alter the exterior oem design of the motors appearance. Street guys will benefit more heat sink however, mayby at some point my street bike will wear a set of these barrells.

BiffTirkle · Posted: February 2, 2008, 12:10 pm Post subject: Re: Mike's XS new 750cc kit

im chompin at the bit to get one of those kits. last weekend i went and picked up 2 engines, 3 sets of forks, 2 boxes full of misc parts, and a set of mag wheels with the drum brake rear hub!!! all for 80 bucks!
i got the engines to rebuild, so i have a starting platform, but if i am to put a kit that nice on an engine, id want to rebuild the entire engine. im having a hard time convincing myself that i dont need that kit! besides it will be a while before i get that engine completely rebuilt, and money certainly doesnt grow on trees!

midnrider · Posted: February 2, 2008, 1:53 pm Post subject: Re: Mike's XS new 750cc kit

80 bucks, man I'm envious...and yea it will change the engine profile, but to me that's a good thing I think it will look 'beefer' and keeping it stock looking is way not an issue (good thing to as much as I am moved from it...lol) I'm going to lap the valves...wish I could afford porting...maybe next year.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

You can clean the ports up yourself using a Dremel. They're just terrible from the factory with many casting flaws in the ports themselves and bore ridges in the valve pockets. Take a good look at them and you'll wonder how they flowed at all. Cost would be about $20 for a few assorted Dremel bits.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

That is one SWEET kit.

It is really a deal at 500 bucks right now too.

Imagine how angry you'd be if you'd just installed your regular 750 kit at 450 bucks, not even gettin the cylinders.

It says it's a special introductory price so you know it's gonna jump soon.

I really would like to get one but I'd want to have new rods put in and go all the way if I was gonna do that.

My question for anyone is this: I have heard rumors of 750 kits having power enough to crack the aluminum around the output shaft. Has anyone had any experience with this? Is there precautions I could take to prevent it when building the 750?

royfisk · Posted: February 2, 2008, 8:15 pm Post subject: Re: Mike's XS new 750cc kit

TT ive seen that on 750's but with road race cams and high rpm's big old carbs, lots a gas.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

royfisk wrote:

TT ive seen that on 750's but with road race cams and high rpm's big old carbs, lots a gas.

Oh no.......that sounds like something I'd be building too.

kingwj · Posted: February 2, 2008, 9:34 pm Post subject: Re: Mike's XS new 750cc kit

Can the stock carbs, exhaust and cam be used with the kit or will you be suffocating the motor? If not it gets pricey pretty quick, especially for a 30 year old bike.

midnrider · Posted: February 3, 2008, 2:22 am Post subject: Re: Mike's XS new 750cc kit

man ya read this and you hear that, but I have read that cams don't play as big a role as some think and that properly jetted stock carbs (esp. the pre 1980 ones) can flow gas just as well as VM's...I think lapping and cleaning up the valves and up'n the cc will be pure plus, and I am jammed over the purchase, hell, I can't wait to take that first ride!

royfisk · Posted: February 3, 2008, 10:30 am Post subject: Re: Mike's XS new 750cc kit

midrider if you dont think carbs and cams dont play a role in the way your bike performs your sadly mistaken. Carbs dont flow gas either, they mix gas and air, they actually flow air and yes they will flow the air as will any other 38mm carburator its the way they work that makes the differance. If your theory had any potential at all everyone at the drag strip, and road course.s would be running the same ols carbs and winning but but that dont seem to be the case now does it??? Also note that porting is the biggest power boost you can get from a 650. I'll bet you a stock 650 carbed and cammed ,ported, and free flowing exhaust ,would kisk a 750's with stock porting , exhaust, carbs but ALL DAY LONG. If your going to big bore its not a cheap date. its a waist of money to go part way. The heads cant flow enough through the exhaust to begin with and thats stock. Heck if you were to save your big bore money and just port, cam, and carb yyou would find a tottaly differant beast more then you bargained for.

royfisk · Posted: February 3, 2008, 10:46 am Post subject: Re: Mike's XS new 750cc kit

tt I left out a little factor, compression ratios. Those are a little higher compression engines then what mikes is selling and you probably wont have to much problam . I know you dont need schooling on the rest of the engine building process, so go get um.

grizld1 · Posted: February 3, 2008, 12:04 pm Post subject: Re: Mike's XS new 750cc kit

Yo tt, got those flywheels tacked to the pins? Don't know the cure (if there is one) for the tranny output shaft support--be a bit hard to reinforce it without a risk of deforming the bearing boss, I'd think. Michael Morse would be the go-to guy on that. But some racers have gotten a lot of seasons of out of 750's. The only prevention I can think of offhand is to make sure the bearings on that shaft are in real good shape so the boss takes less of a hammering.

kingwj · Posted: February 3, 2008, 12:07 pm Post subject: Re: Mike's XS new 750cc kit

Looking at the dyno curve 1 it looks like you gain around 7.5 hp with the camshaft, pod airfilter and exhaust modification, mostly above 6000 rpm. I'd consider this a 'cammy' engine, you wouldn't want to use the extra power most of the time because you are winding the crap out of the engine. The 25 hp gain is bought for around $2000 and includes cam, valve springs, carbs, exhaust, big bore kit and much labor. It appears the power comes on around 4500 rpm, a more reasonable number and much more streetable. They also state the 750 kit is worth about 7.5 hp alone. In reality in today's world 2 grand isn't that much for this kind of gain but it is a hard decision regardless for a 30 year old bike.

www.mikesxs.net/parts/...0750_1.png

www.mikesxs.net/parts/...0750_2.png

Mikesxs · Full Member Joined: Feb 06, 2007 Posts: 134 Location: FL

Dyno Chart 1 shows the 43HP that the stock engine puts out (Rear Wheel). Dyno chart 2 shows the increase (about + 21HP at the Rear wheel) that the engine puts out with the XS Performance Big Bore Kit, Cam and Pod filters (but with the Stock rejetted BS34 CV Carbs).
NO porting work of any kind has yet been done!
We have more XS Performance parts to come including a 2-1 Exhaust that is street legal yet added an amazing + 8.5HP over using a stock system.
This has been Dyno developed again by our Dutch distributor, Jerry Heiden of Heiden Tuning. The free flowing aftermarket mufflers used on this bike added a lot also but not as much as this 2-1 pipe coming later this year. We also have further tuned the Dellorto's and will later offer additional bits so the pumpers will offer more power than the +3 HP shown on the dyno chart attached to the Dellorto Listings. Who says these antiques can't be made to dance ! Also New Tranny Bearings and about 300 more new parts are still in the Pipeline. Mike Lalonde Mikes XS

kingwj · Posted: February 3, 2008, 3:20 pm Post subject: Re: Mike's XS new 750cc kit

Mike,

Thanks for keeping us running. I think I speak for around 2400+ other XS owners in the group. Make sure to keep Mr. Heiden happy, seems like an amazing guy.

royfisk · Posted: February 3, 2008, 3:41 pm Post subject: Re: Mike's XS new 750cc kit

This is respectable considering that the 2007 triumph 900 scrambler is advertised at about 47hp and 43 ft pds of torque. cycle world may 2006 pg 50. And thats a air cooled parralell twin at 860 cc's .4 valve per cylinder engine. Why cant yamaha produce something like this? So mike do I smell 60 plus horsepower comming? And higher torque numbers???

Mikesxs · Full Member Joined: Feb 06, 2007 Posts: 134 Location: FL

See Dyno Chart #2 attached to Site Big Bore Listing. Almost 64HP at rear wheel already without the Dellorto's or Porting. More lower down power being worked on also. New cylinder Head design is Not a problem either but I doubt many would put up the estimated $600-$800.00 price. All our items are produced in Large quantities. Small runs of anything are a waste of time for parts makers. OEM's get all the production time these days and old bits just get fitted in when they can (often a long wait).

Mike Lalonde Mikes XS

royfisk · Posted: February 3, 2008, 4:50 pm Post subject: Re: Mike's XS new 750cc kit

mike I see 81mm pistons listed but no 80mm pistons. I see both ring sets. Is there a reason there are no spare pistons available? I beleive that the cam profile of the web cam 59grind would get the low end out along with extended intake manifold.

Mikesxs · Full Member Joined: Feb 06, 2007 Posts: 134 Location: FL

80mm. pistons are in stock if a kit purchaser needs them but we are not offering them alone for now as most of the first production of forgings has been reserved for the Big Bore kits. We also have 533 big bore pistons for our European distributors and will run more when we need them. Performance parts are being done as a promotion for the 650 and prices are being kept down. Hundreds of thousands $$$$$$$ has already been laid out so I need to pace things out.

Mike Lalonde Mikesxs

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

Mikesxs wrote:

See Dyno Chart #2 attached to Site Big Bore Listing. Almost 64HP at rear wheel already without the Dellorto's or Porting. More lower down power being worked on also. New cylinder Head design is Not a problem either but I doubt many would put up the estimated $600-$800.00 price. All our items are produced in Large quantities. Small runs of anything are a waste of time for parts makers. OEM's get all the production time these days and old bits just get fitted in when they can (often a long wait).

Mike Lalonde Mikes XS

I would gladly put up with the estimated 600-800 dollar price.

I like the 750 kit you've put out a lot. Looks like a sweet deal. Honestly though, if you had the head for sale as well that'd be what I'd buy first.

Regardless, I'm real excited to see all the new stuff in the works. I appreciate all your hard work and great service over the years. Thanks.

royfisk · Posted: February 3, 2008, 6:29 pm Post subject: Re: Mike's XS new 750cc kit

How about a tottal package, head, big bore, carbs,and cam. Now novice builders have a package that will perform out of the box. asummeing they can put it together.

Jack · Full Member Joined: Mar 15, 2005 Posts: 411

Mike...........what would it cost to get the lobe separations ground to 104 both intake and exhaust on the billet cam? I'm building a long rod motor and want to move HP and torque peaks lower in the RPM for broader power band. At the moment I'm porting ahead for a member using your billet cam,etc using VM36s,it'll be interesting to see outcome after a few dyno pulls................Jack

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