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Discussion Starter · #1 ·
Looking for info onthese
Drop in piston kit
830 Big bore
840 Bigbore

I plan one doing one of these next season I have read the Dynotech report on the 830 and have been told one for the drop in kit is coming soon.
 

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Kooter said:
I think the drop in pistons would be better than a big bore. I have one of the big bores and well.......lets just say it has spent more time in the garage than on the snow
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Why? What happened to it?
 

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Discussion Starter · #6 ·
dm04REV800 said:
I have to say the SHR840 (Big John) I have ROCKS, no problems with the sled has run GREAT !!!! real STRONG !!!! it has been a blast "edit for bad language" off the new machZs

doug
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How many lenghts are you getting them by? I think its really going to freak them out when an old 01 800 beats them and by the lack of response of this subject my sled will be whipping a bunch of sleds!
 

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Discussion Starter · #7 ·
Kooter said:
I think the drop in pistons would be better than a big bore. I have one of the big bores and well.......lets just say it has spent more time in the garage than on the snow
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Which big bore kit did you use?
 

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Big Johns 840cc is dialed in, with out his help my RKT would be burned down long ago. I am running the same jet size as B.J. at 1700 ft. Thank you B.J. Kelsey is a good guy, it is just hard to give sea level safe spec. when you tune at altitude. Thank you also Kelsey.
 

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i have the drop in kit from rkt...I weigh 280lbs, ride with a 200lb friend with a new apex that beats everything around....except the rkt 800 drop in kit in my renegade...just my .02...this thing PULLS! (oh, by the way...mine is a 136" renegade with 162 studs) his is a standard track with 168 studs...
 

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Ski-B said:
Big Johns 840cc is dialed in, with out his help my RKT would be burned down long ago. I am running the same jet size as B.J. at 1700 ft. Thank you B.J. Kelsey is a good guy, it is just hard to give sea level safe spec. when you tune at altitude. Thank you also Kelsey.
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agree 100% cuz mines burned down right now, shoulda talked to b.j. more the altitude really plays a factor in tuning thses kits, both are very knowledgeable but bj has got the flatland setups... period. i'll be getting more timing put back in to hopefully cure the cold detonation thats happening under load and mid throttle . really rich off idle, and ok on the trails but when its gotta work it gets lean. the 600ho needles with a shim to start with and 500mains and work from there, 4corners seizes arent cheap to fix especially if it cracks the cyclinder
 

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I'm wondering what kit to get myself, I have an 01 at high alt.
Seems to me that the drop ins will get me to 152 hp and then port it for another 10 hp and you'll be right up there with the BB kits at 162 hp. Does this seem about right.
Would the 830 or 840 be worth the extra money?
 

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The biggest dif between the to kits is, Big John 840, 7950-8000rpm, RKT 827, 8200-8500, both make the same or similar HP. The larger cc does not add much more HP, maybe 3 HP. It is a matter of what RPM you prefer. Bondi Engines makes a ported 800 cylinder, with an air box mod that makes 157HP on the same dyno the RKT made 160HP with trail jetting or 165HP with super lean jetting. It is your choice.
 

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I need to jump in here and give more detail on the 840, I have held this thing wide open for 1-2 minutes powder sidehilling across a 1/2 mile hill. I sold the machine and heard that it has been trading high marks with a KK on NOS. On the hill, steep and deep. I can't say enough good things about the fun with the 06 Summit HMX and 840 combo.
 

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Ski-B said:
Big Johns 840cc is dialed in, with out his help my RKT would be burned down long ago. I am running the same jet size as B.J. at 1700 ft. Thank you B.J. Kelsey is a good guy, it is just hard to give sea level safe spec. when you tune at altitude. Thank you also Kelsey.
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What jetting are you running?
 

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Gotta LOVE all the MIS-INFORMATION that gets posted on chat rooms!

First of all.. the RKT 827 dyno'd at Dyno Tech Research late last year had 9,000 miles (not a typo) on the crank and 1500 miles on the top end kit and made 166.4 HP on the "Lean jetting run" and 163 + HP on the "SAFE Jetting" run

Hmmm,,, Since then this SAME sled has logged another 3K plus mile and had jetted DOWN 2 sizes from the "Lean jetting" main jet....

Hmmm So, how LEAN really was that... This engine is DESIGNED to run on 91 octane not 85 octane (although that is an option) and the DTR run was an 85 "SAFE" run... and like I said... over 4500 miles ont is top end and over 12K on the bottom with NO issues and LEANER jetting than the "LEAN Jetting" run at DTR....

The 827 with RKT porting and stock pipe and can will hit 170HP all day long!!
but the 166.4 with 2 sizes large main and 9K bttom end is still great numbers.. Keep in mind that kits porting is 3 revisions old and we have made improvements in power from that porting arrangement.> We also have an MPEM timing curve upgrade that adds some performance that was NOT on the DTR tested sled either..

The other "tweener" built 830 that made 163HP with an aftermarket can (that cost it power) at DTR is also RKT "tweeked" you can ask Tweener or the owner of the engine for more details is you feel you need more info...

Bottom line... 163 PLUS hp is obtainable ALL DAY LONG

1 Down 1 more (for now) to go...

As for somebody having raced in the steep and deep a RKT ported 800 drop in kit with a SHR 840... This is simply not true and has never been done... How do I know... Because there are only 2 RKT ported drop in kit in existence and 1 is in Alaska and the other is in Canada and is not even assembled as of today....So, how is is possible for a guy in Minnesota to have raced in the steep and deep either of these engines?? ANSWER: It is NOT and has not been done...

Does the RKT drop ins without porting make the power of the RKT ported 827 or the SHR 840??? Probably not... Should they??? NOPE!! Will the RKT drop in kit with RKT porting make the power of the RKT 827 probably not but I have not tested them directly yet so the REAL answer is" UNKNOWN" how about the SHR 840??-->>Same answer "UNKNOWN"
So to sit here and speculate make sound great and all but is NOT FACTUAL in ANY WAY SORT OR FORM!!

These drop ins have proven themselves WITHOUT porting to be a solid performer ...Since we have TONS of time on them and you can search for others running them on THIS forum and see that they are ALL happy and DID see a VERY noticable performance increase! So, they DO work as advertised.

The RKT 827 (really an 830) has also proven itself both in the field (over 200 of them out there) and on the DTR dyno.. Has there been people that has had issues with them.. YOU BET.... but this is to be expected when you put out that many kits.. Overall.... the satisfaction percentage has been WELL ABOVE what I expected and I am very happy about that..

The SHR 840 has also proven itself to be a solid package...It has not been on DTR but I am sure it would do well on there also...Has there been people that have had problems with this kit?? YUP,, Like I said,, this is to be expected and the over-all satisfaction has been very good... Has it been compared to a RKT ported 800 drop in kit on the hill (like posted on here).. ABSOLUTELY NOT!! (see above for proof) Has it been compared to a NON RKT ported set-up?? WHO KNOWS!! It may very well have been.... If this is the case then it should be posted as such!!
Like I said.. A lot of misinformation...

Kelsey
 

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Kooter said:
I have the 827 by RKT...Tell me about the 4 corner seizure....it's happened to me also and It's in the garage still
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Once again.. WRONG!!

You have a one of a kind 820cc SLEEVED VERSION kit that is the only one is existence!!

Should we go into WHY you have this one of a kind engine??? Sure .. Why not.... since you seem to get thrills by posting all this mis information...

So, why does Kooter have a SLEEVED 820 (not 827) kit??? and why is he having problems??

Let's dive into this a bit....

You may ask.. why would somebody opt for a sleeved kit from NikaSil cylinders??
Well, the kit was initially and NikaSil 827 kit and the person installing the kit was having problems with the cir-clips so they decided to take the pliers and "squeeze" them so they were smaller since they were not able to install them before... Well... this took ALL of the "Spring" tension out of the clip and the clip came out (as to be expected) in a short time and completely DESTROYED one cylinder.... So, Kooter asked what the options were and I told him either 1 new cylinder or sleeve both of your existing jugs.. He chose the sleeved version and went to the 83mm piston (per my suggestion) so he would have 1 over-bore left of there ever existed another problem... We can stop at this point (bit there is much more to this story and it would only make Kooter look very bad so I will choose to end it here and HOPEFULLY he will choose to due the same)

I HATE airing out dirty laundry on these chat rooms but what I HATE even more is MIS INFORMATION like this.. Bottom line.. This engine is NOT an 827 nor is it even a NikaSil plated engine... SO, keep that in mind when this guys speaks up about "his" engine...

Kelsey
 

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Ski-B said:
Big Johns 840cc is dialed in, with out his help my RKT would be burned down long ago. I am running the same jet size as B.J. at 1700 ft. Thank you B.J. Kelsey is a good guy, it is just hard to give sea level safe spec. when you tune at altitude. Thank you also Kelsey.
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LAST ONE FOR NOW! "edit for bad language" I hate doing this.. But misinformation is misinformation....

Ski B.. has an 820 NOT and 827 (1st part of bad info)

Second... He has a Decker timing curve which has WAY more timing EVERYWHERE than I recommend... (2nd part of bad info) Please correct me if I am mistaken! I do get people mixed up sometimes..

Third.. ANYBODY who knows how DPM works KNOW that people at 10K feet run the SAME main jet as the people at sea-level.... SO.... main jet jetting is the SAME for 10K as sea-level.... SKI B is running AT LEAST 5 sizes (420's if I recall)(More like 8 sizes) too large of main jet and for sime reason does not choose to jet down (his choice and I have no problem with that) MY instrcutions STATE to richen up the mid-range via needle clip change or shim.... This works excellent for controlling midrange lean but when you have MORE timing in the middle (like the Decker curve has programmed into it and like Ski B has in his 820) then there MAY be more needed to control mid-range heat..... IF ANYBODY has the RKT curve programmed in the MPEM then the needle adjustment is MORE than sufficient to control mid range heat.. Other curves????? Don't know.. RKT Curve...> Proven safe!

But you are correct in stating that Big John is a great tuner and is always willing to help... I consider BJ much more than just a "customer" I consider him a good friend and value his tuning knowledge. We talk quite frequently and compare notes.. he and I are working very hard TOGETHER to provide PROVEN and Reliable DOO engine upgrades.. I hope we are succeeding in that quest..

But,having said all that.... I can, honestly, say that I have more tuning experience with my kit than ANYBODY (hmm. hard to imagine that one... LOL) Having said that... EVERY engine responds different to mods.. Most of the time they all respond in a similair manner. but there are always a few that respond WAY different or not at all.. I have had a few engines that the kit would flat out not make the BIG power on or have reliability issues and require all sorts of strange set-ups to work at all.. BJ has witnessed the same with his kits...this is a strange thing that is very hard to explain... Hopefully yours is not one of "those" engines....

I just got back from meeting some customers with drop in kits and 827 kits in Wyoming and Colorado and riding with them all week... No problems The 827 is an 04 as is the drop in kit. equipped sled. The 827 is running stock needle in stock position and running 350 mains and is still rich.. It is also very fast! We also tested both MPEM curves on both kits and the new curve does add performance (switched them out right on the mountain so we could have a DIRECT comparision (the ONLY way to REALLY tell what is working and what is not)

I am REALLY not trying to come on here and be arrogant (even though it might come across as such)... But If you are going to post statements that are supposedly "FACTUAL PLEASE include all the facts about your set-up... and the FACT is.. you have not got the set-up I recommend with the kit... You have "other" additions/changes.. These things REALLY make a difference..

These chat rooms are great for getting information but MANY times the information is not entirely accurate and wrong information can cause problems...

That is the whole point..

Kelsey
 
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