what's up with my 780

F

fordsrx

Member
Joined
Jan 10, 2005
Messages
52
Location
Hay River, N.T.
last year i put a 780 cpr in my 00. after i finally sorted out my electrical,(new wiring harness) it was time too put it away, well besides of a couple of high speed passes. that was with a heel clicker, Bender clutch set up, and i still could only get 190km/h on hard pack. this year i put in a H.H. from simon's and I'm now close to 8500-8700 but only 140km/h and feels like when it's getting up to mid range something is holding that motor back. it was pulling harder when the sled was stock(taking f7 and all 800). i'm going too double check (valves and carb setting agian)the sled has a ripsaw and mostly like to do 660 snow drags. do you guy's have any suggestions greatly app.
 

Mine works great, but the jetting specs he gave must have been for 500ft drags because it wouldn't have lived very long otherwise. My midrange is a touch lean but accaptable. Mabee your not getting enough fuel??
 
idling the sled below 1000 the servo pulls the valves open. i set my valves using a gauge, I was going to manually set them by pulling off the exaust and using my finger to adjust 'till flush. as far as jetting. I'll try 155 across all 3. I have 152.5 in there now. I still don't know what this thing will do agains other big bore sleds
 
I had to add alot of weight to the tip of my HC's to hold it at 8500. I was running my 98SRX at 8300 and added 3-4 grams to hold it at 8500 after the BB, it sure feels strong. I came up with 155's and 47.5 pilots to work the best. As for the power valves, I adjusted mine with the manifolds off so I knew they were perfect. ;):D
 
Do you have bored carbs,what's in your secondary for a helix.Check the pwoervalves and add some tip weight to bring them down to 8500 max.
 
thanks guys for your replys. yes the carbs are bored to 38 and the helix is 52/44 i was actually trying to take weight off too bring it up to 8500-8700 it seems like i have to remove quite a bit of weight to get it up there. can't remenber the weight i'll let you know after i come back from the shop. hey cacsrx1 i was told to run 55 pilots. maybe that has something to do with it????
 
I was running 45's but my idle would hang, with 47.5s it still hangs when its cold, I just blip the choke and its fine. I m running stock carbs at 1300 feet with Variflow, so what Im running for brass may be far from what will work in yours.
 
My buddy has 55 pilots in his 01 cpr big bore with bored carbs.Get ahold of mrviper he will get you running right.
 
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