Sasha Rudolfski

Big Bore and Stage 2 Hotcams Questions

13 posts in this topic

Now that my FCR mx 39 is running nicely I have been eyeing Cylinder Works Big Bore 94mm kit and Stage 2 Hot Cams.   

My DRZ400s has about 2500 miles on it.  

If I do the Big Bore using single base gasket and Hot Cams will I need to replace anything else to keep it reliable? 

- the manufacturer says its drop in/bolt on but I've read here on TT that may not be completely true for stage 2...

I've heard of at least one person here using stage 2 hot cams on the intake and a web racing cam on the exhaust for best top end performance.  

I know if I go that route I will need different valves and valve springs for sure but which ones?

What are the risks to reliability installing Big Bore / Stage 2 Hot Cams (assuming installation is done correctly)?

Any steps I can take to minimize risks or anything I should be looking out for after install?

For break in period after install; I live in a big city so I do not have access to a road without stop lights/stop signs/ traffic laws.

Do I need to load the bike on a truck after install and find a place where I can do the break in procedure correctly?

Does any maintenance change with these mods? 

For those who have done one or the other or both; How did your bike feel after install (can you rev it higher? power wheelie? more power in higher RPMS? more speed?)

Any insight appreciated! Thanks!

 

 

 

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5 hours ago, Sasha Rudolfski said:

Now that my FCR mx 39 is running nicely I have been eyeing Cylinder Works Big Bore 94mm kit and Stage 2 Hot Cams.   

My DRZ400s has about 2500 miles on it.  

If I do the Big Bore using single base gasket and Hot Cams will I need to replace anything else to keep it reliable? 

- the manufacturer says its drop in/bolt on but I've read here on TT that may not be completely true for stage 2...

I've heard of at least one person here using stage 2 hot cams on the intake and a web racing cam on the exhaust for best top end performance.  

I know if I go that route I will need different valves and valve springs for sure but which ones?

What are the risks to reliability installing Big Bore / Stage 2 Hot Cams (assuming installation is done correctly)?

Any steps I can take to minimize risks or anything I should be looking out for after install?

For break in period after install; I live in a big city so I do not have access to a road without stop lights/stop signs/ traffic laws.

Do I need to load the bike on a truck after install and find a place where I can do the break in procedure correctly?

Does any maintenance change with these mods? 

For those who have done one or the other or both; How did your bike feel after install (can you rev it higher? power wheelie? more power in higher RPMS? more speed?)

Any insight appreciated! Thanks!

 

 

 

Some thoughts........

at 2500 miles the motor is "fresh" and really doesn't need pulled down to have the piston and jug replaced.  That's a relatively involved job.  My thoughts are wait until its a bit tired then have a refresh with the Cylinder Works Big Bore kit. The cams (stage 2 hotcams) however are another matter.  Quite simple to fit flowing the instructions on here and with the cams.  Think really hard about top end power for a minute.  Is it possible that more midrange ride-ablity is a better option on a road / off-road bike? (it's not a track/race bike is it?)  Also not having to deal with valves and valve springs at this time, the motor not having seen to much work yet.  Not to put you off if your hell bent on spending $$$. Some stage 2 Hotcams will wake the mid and top end up quite a bit. What do I mean by that.  The bike rev's more freely from about 4000RPM to well over 7000RPMs (I have touched 8000rpms on the odd occasion) .  There is no the falling off in power at the 6000rpm mark (so yes more power).  I have found that the cams promote a more spirited riding style, you may want to shorten the recommended service intervals to accommodate (if your worried). I managed to break in the cams quite nicely riding from my home in local suburbia out around a 100km (60 mile) course of roads, mainly back roads and some higher speed limited areas.  There were a few traffic lights but judicious judgment meant no stops were had.  I used the recommended high zinc content oil and pre lubricated the cams with the recommended products on install.  It's also the perfect time to install a manual cam chain tensioner.   A Dynatek FS CDI (programmable) will make a difference on how the bike comes onto power (Ohiodrz400SM has a really sublime ignition advance map for this unit).  A programmable CDI will stand you in good stead for other modifications as well.  That's my 2 cents.

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Something to consider...

Stage 2 Hotcams reduce power below 4000 RPM.  

Clutch-ups need to be revved up passed 4k RPM just to lift the front end.

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2 minutes ago, Stuwy123 said:

Something to consider...

Stage 2 Hotcams reduce power below 4000 RPM.  

Clutch-ups need to be revved up passed 4k RPM just to lift the front end.

Not my experience at all. Very little difference down low.

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I went from the 2047 and 2048 cams which are basically the same as current stage 2's to the old stage 2 (2003-1In) and a Web 540 exhaust. This combo traded a little on bottom for a little longer pull on top. I went with this combo after reading old posts from the LTZ gurus on Suzuki Central.

 

As far as reliability, my stock valves and springs had 19K miles when the head went to Fast Heads for a Proactive rebuild. They reported that everything was in excellent condition. The stock springs are fine for all Hotcams and off the self Webs. What does lack of a decompression release do to the starter? I don't know how much of this is fatigue or due to the cams but I suspect it's the reason I tore everything apart on my bike.IMG_20180613_074133316.thumb.jpeg.4f0947acad4c6476755fafe917a7aae8.jpeg

 

 

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18 hours ago, Sasha Rudolfski said:

Now that my FCR mx 39 is running nicely I have been eyeing Cylinder Works Big Bore 94mm kit and Stage 2 Hot Cams.   

My DRZ400s has about 2500 miles on it.  

If I do the Big Bore using single base gasket and Hot Cams will I need to replace anything else to keep it reliable? 

- the manufacturer says its drop in/bolt on but I've read here on TT that may not be completely true for stage 2...

I've heard of at least one person here using stage 2 hot cams on the intake and a web racing cam on the exhaust for best top end performance.  

I know if I go that route I will need different valves and valve springs for sure but which ones?

What are the risks to reliability installing Big Bore / Stage 2 Hot Cams (assuming installation is done correctly)?

Any steps I can take to minimize risks or anything I should be looking out for after install?

For break in period after install; I live in a big city so I do not have access to a road without stop lights/stop signs/ traffic laws.

Do I need to load the bike on a truck after install and find a place where I can do the break in procedure correctly?

Does any maintenance change with these mods? 

For those who have done one or the other or both; How did your bike feel after install (can you rev it higher? power wheelie? more power in higher RPMS? more speed?)

Any insight appreciated! Thanks!

 

 

 

 

Skip the BB until the bike needs it and throw in a set of E cams or Stg. 2 hotcams and enjoy the nice fat midrange.

I am very happy with with my set up and did not notice any major drop in low end power (and I am not light at 240lbs).

My bike is now way more rounded as it has massive mid-range power/response while actually pulling in the upper rpms vs. just revving for nothing like before. All while no noticeable loss in low end with knobies/trail use.

 

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I have the old stage II cams 2003 in and ex.  I had the head rebuilt by APE.  I have an FCR39MX from TT, a full MRD pro exhaust, I love it the thing pulls from the bottom up AND I use it at the race track.  I put in an E CDI, rev limiter is about 9850 according to mister trailtech vapor.  I routinely bang off of it when riding and at the track.  Revs fast, very nice, also you can get the front up pretty easy at low speed.  I have an SM.  I also have a stock S, that may get a set of E cams that I have stashed.

As to breaking it in.  I do 3 heat cycles at idle.  Let it run until the fan comes on, then shut her down and cool back to ambient.  Then I go ride her like I stole her.  Never an issue, I have good ring seating.  I know this because last time I had a poor job done on my head and a valve spring failed.  I did learn via Erik that there is an exponentional increase in load on the valve springs for those extra few hundred RPM.  That said, when I pulled her apart, I replaced everything in the cases except the balancer and tranny gears/shafts.  I installed a new crank, rod, piston, and big bore kit.  I am happy with her now, I think my valve spring had been going for a while.  The motor now is awesome.  I should have listened to Erik, I should have done this rebuild the first time I did the big bore so I would know the condition of the engine I am about to modify/spank.

 

All that said, I did it the way I did it, so YMMV, I am just pointing out an alternate method which may not work for everyone.

 

I do recommend the big bore and cams.  I do not want to discuss break in, I am pretty sure nowadays there are several choices.  The plus on the current stage II cams is the decompressor.  My cams do not have that and sometimes it has a little trouble rolling the motor.  Of course it normally starts in less time than it takes me to let go of the button.  Be sure and let us know what you did.

 

P.S.  I used assembly lube and changed the oil at 100 miles.  I had zero metal and I put Royal Purple in if anyone wondered.

Edited by TLRDoug

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On 6/12/2018 at 8:21 PM, Stuwy123 said:

Something to consider...

Stage 2 Hotcams reduce power below 4000 RPM.  

 

No question my E exhaust cam gives more power from idle to redline than my 2048 Stage 2. Unbelievably better in the singletrack. :thumbsup:

Going to have to try the 2003 exhaust at some point. :banana:

DRZ-cams.gif

Edited by Bermudacat
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I installed the fcr39 at 2000km and did BB, stage 2 hotcams and single base at 5000km. I've put a hard 2500km on the bike and it runs great!

Do it. 

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