• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

Need clutching help....Silber Pro rmk spiking rpm at throttle stab

wellfed777

Well-known member
Lifetime Membership
Dec 1, 2007
2,226
412
83
Oregon
that's not hitting the rev limiter that's a stutter or bog
i remember that guy posting but can't remember what he figured out
not sure what year kit that is
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
I've recorded mine go above that 8600 and make the same sound. The rev limiter sounds different than this? Mine sounds like this only on the intial stab of the throttle from stand still or from hard on off stabs.

Sent from my SM-G920V using Tapatalk
 
Last edited:

diamonddave

Chilly’s Mentor
Lifetime Membership
Apr 5, 2006
5,569
3,866
113
Wokeville, WA.




That was forum member Diehardpoo 2014 kit running low altitude in Alaska. It was a special 2863 set up not the 2860 sold to the masses. I purchased that kit from him and it's been a perfect dialed set-up since install.

It's hard to tell from that video if it's a lean (or possibly a rich misfire) or rev limiter.

At the time of install, I made some minor clutching changes, exhaust valve spring change, intake mods, and BR9EYA plugs gapped to 0.015" and it's running 8 lbs on the gauge at 7,000 ft.

It runs perfect down to 2,200 ft as well.

We're not sure if that vid was taken with the original 2014 Silber reflash or the mid year updated reflash. Because when I got the kit, the stock map was loaded. This was/is a special hacked ECU which allows the end user to change maps.

I have a lot of goodies left to install now on the motor that have me curious.
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
This is before the goat 6 flash. There is a vid also after the goat 6 flash where it difinitely runs better, but still does it. My ecu was flashed in like december of 15 so that should be the most recent flash? I found the post where others had the same problem and this vid is in it. http://www.snowest.com/forum/showthread.php?t=403146&highlight=silber+problem I checked my exhaust donuts today and they are are leaking some, engine was cold, so I will have to make a boost leak tester and cover the donuts with that high temp silicone and retest. Diehard said he never got it figured out and sold it.
 
Last edited:

wellfed777

Well-known member
Lifetime Membership
Dec 1, 2007
2,226
412
83
Oregon
it's hard to compare sled to sled it seems
maybe because rider,conditions,sled setup etc etc........
as proved by Dave above :face-icon-small-hap
i would try the weight thing
also post a video of your sled if possible
and go over everything some top contenders for issues are

clutching meaning worn or broken parts
power valves
exhaust or boost leaks
wires loose or rubbing
bad grounds
spark plugs /wires/ gap
boost gauge is very handy

good luck man
in my personal experience when my pro hit the rev limiter it would go into full DET mode and i'd have to shut it off and restart
that's why that video doesn't seem like hitting the limiter to me again that was my sled so who knows
 
R

roni87

Well-known member
Feb 11, 2011
513
213
43
I Falls, MN
Pop bang.

I had same problem when trying the stock clutching at 1200 ft. Only had a 7psi spring for the first week and added all the weight I could to the rooster weights.
Droped the secondary spring to my black/purple I had and it nearly went away.
So yes droping spring weights is where I would start along with switching your helix to the 44-48 ramp. I now run a 150-310 primary spring too because I would get the Rev up pop you are experiencing when trying to clutch for 8100-8200 rpm.
I'm also running a 48-44 helix so the initial load is higher.
Since then I also have a 120-200 sec spring I run but might go back to the srock 800 or maybe the 160-240 black purple one.
At 8 to 10,000 I'm running a red, green, blue weight from heal to tip.
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
All good info. I see others had the same issue, so hopefully I get it figured out! So tonight I put in a straight 48 and black purple secondary spring and left everything else the same. Pink 180 320 primary, 80 gram rooster weights spread evenly and 7lb boost spring, 3/4 av fuel with a splash of 91. Same result. I will say when the sled was cold it seemed to do it less. Tried both eth and 91 settings. The clutches were hot making like 18 100 yrd runs on flat ground at 1500 feet. (Grass field on my place) I think the belt is just is slipping from the power. Both clutches felt the same temp, couldn't hold my hand on them. I did see it over rev during the pop. I have the heavy tungsten washers coming for the weights and a almond red primary spring. NO det but I suppose I can try the 5lb spring tomorrow. Let me know ur thoughts...
 

wellfed777

Well-known member
Lifetime Membership
Dec 1, 2007
2,226
412
83
Oregon
do you have a boost gauge ?
i wonder what actual boost you're making ?
others have said the boost made by a spring is actually more than set spring #s

with a 7lb spring you may be making 8-9 lbs ?
plus according to silber weight chart you would barely have enough clutch weight at that elv. ( octane is on the edge also)
try a 5lb spring easy test for the field

one more thing you clutches shouldn't be that hot from flat field drags or slip because of power
it should either spin or wheelie over backwards :face-icon-small-hap
something seems off there?

let us know how the 5lb spring acts
 
Last edited:

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
10 lbs boost it says for the most part. I never had the det light come on and they said half and half for fuel and I am more than that and its 30 degrees out. Its loose snow so it was spinning but hooking good and a 163 so harder to wheelie. I do maybe have a little light black marks 3/4 " down on at the top of the primary. It definitely pulled harder with the 48 helix. I have another belt, brand new though. Think it will go boom on those short runs if I warm it up a bit? Yeah for those short runs, the clutches should not be that hot. I know the weights are light, hitting 8400 but I had the 75 grams at 9000 feet and it was still doing the same thing. Those tungsten washers are on the way. Not hitting limiter or misssing at full throttle.
 
Last edited:

wellfed777

Well-known member
Lifetime Membership
Dec 1, 2007
2,226
412
83
Oregon
maybe i'm misunderstanding you ???

are you saying your boost gauge reads 10 lbs of boost
with the 7 lb spring ?
and your house/field is at 1500' elv. ?

sorry just trying to be clear
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
Yeah,sounds like a lot of them read high on the guage that came with. Other silber turbos I have read the same thing. Dont have a bench mark other than its supposed to be a 7lb spring. Yes, testing in Minnesota right now.
 
Last edited:
R

roni87

Well-known member
Feb 11, 2011
513
213
43
I Falls, MN
Primary spring

Try your stock primary spring in there. It will be little doggy on engagement to mid...lower engagement too thou. Shouldn't do the pop with it like that.

I'm not a fan of the super stiff pink spring or the coil bind associated with it. That's probaby part of your heat issue

Where are you in mn? I have the 3,5,7 psi springs and assorted springs in northern mn.
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
Thanks Roni, yeah, Im way south. I put in the 5lb spring today and ran perfect. The 7lb was quite a bit stonger suprisingly.
I am pretty certain I just need more weight. I put in a 140 330 in the primary and same pop. The power did feel a little smoother. I watched today and every time the rpm got high on the stab it popped. If my belt is slipping in the primary, lower start rate or higher finish is more imortant? which Im liking the 48 helix and black purple. I think it has helped some to load the motor but wonder if that is too steep for out west and will create a lot of heat? So I should add more weight where on the weight profile for the throttle stab and hard acceleration to prevent that spike? Its 8200 on top and doesnt pop holding it wide open. Plugs looked good today.
 
Last edited:

wellfed777

Well-known member
Lifetime Membership
Dec 1, 2007
2,226
412
83
Oregon
good news ! sounds like your figuring it out

keep in mine all sleds are a bit different so you need to tune
to your sled
maybe your sled runs hard/better at a different
top rpm than a buddies or pulls more or less weight etc...
 
R

roni87

Well-known member
Feb 11, 2011
513
213
43
I Falls, MN
Swapped my clutching around tonight. Was too much lag for my liking on last trip out west on 7psi spring and I was over reving with same weight at home with 3psi spring.

Primary spring 150-310
3.5, 5, 4 gram weight heal to tip.
48-44f helix
160-240 black purple.

I think putting some weight in the middle and tip can help with the spike as they are so biased to the heal the way they're cut.
Pulls harder than my lower secondary spring rate and less primary weight setup. No pop when stabbin. 7950-8100 peak. Will probably take the .5gram washer from tip weight when I have some time.
 

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
Were u getting much heat in the clutches with that setup? Thinking about keeping the straight 48 in with the black/ purple spring and still pink primary. The 140 330 was only engaging at like 3900. That primary spring felt like it was accelerating longer though. I see some guys with the steeper helix run the black/lime green in the secondary which has a lot higher finish rate which would grab more and maybe help the spike.
 
Last edited:

Spiderman

Active member
Lifetime Membership
Dec 1, 2007
220
41
28
Mn
Just an update...I got the heavier washers and added weight to the middle of the clutch weights and noooo more pop. The straight 48 seems to be helping too, but I will see how it acts on the hill. Hardly any snow left to test here so im glad its fixed. I appreciate all the help!
 
Premium Features