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Discussion Starter #1
Hey guys I have an 04 preddy 500,I'm having trouble getting it started 99% of the time. I HAVE to hold my hand over the carburetor until it spits back some gas then remove my hand and it tries to fire sometimes it will start up and run and other times I just have to repeat those steps. I've cleaned the carburetor thoroughly, put new piston rings in it, and a new choke cable and just cant figure it out. Would anybody know what it could be? I know I set the timing right, i have a sneaking suspicion it's the valves.
 

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I was going to suggest checking the valves - you are already thinking it - wasn't it done when or before the engine was rebuilt?
 

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Discussion Starter #3
Unfortunately not my valve spring tool did not fit as it was for bigger engines wo I could not even attempt to lap the valves. I can get it to run and it runs great when it is warm, and will start easy when the motor is warm but if it hasn't ran that day it's a pain to get started.
 

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Unfortunately not my valve spring tool did not fit as it was for bigger engines wo I could not even attempt to lap the valves. I can get it to run and it runs great when it is warm, and will start easy when the motor is warm but if it hasn't ran that day it's a pain to get started.
I don't think latebird was talking about lapping the valves. It sounds like you may need to ADJUST the valves because they're too tight.
 

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Sorry OP, I haven't had any dealings with the Predator engine so I did a quick look. I didn't realize those valves use shims for adjustment. The symptoms you describe sure sounds like valves too tight though.
 

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Discussion Starter #6
Okay thanks guys I'll see if I can get some shims found and keep you posted if it works or not. Would anyone know what size of shims are needed? It has hotcam in it, not sure if that matters.
 

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You're outside of my knowledge base on this one OP. latebird might be able to help more.
Here's a list of the different thicknesses of "adjusting pads" as Polaris calls them. If you don't have a service manual you probably should be looking for one.
Good luck and let us know how it goes.

6 3087988 Pad, Adjusting, 1.450 4 USAGE
6 3087989 Pad, Adjusting, 1.500 4 USAGE
6 3087990 Pad, Adjusting, 1.550 4 USAGE
6 3087991 Pad, Adjusting, 1.600 4 USAGE
6 3087992 Pad, Adjusting, 1.625 4 USAGE
6 3087993 Pad, Adjusting, 1.650 4 USAGE
6 3087994 Pad, Adjusting, 1.675 4 USAGE
6 3087995 Pad, Adjusting, 1.700 4 USAGE
6 3087996 Pad, Adjusting, 1.725 4 USAGE
6 3087997 Pad, Adjusting, 1.750 4 USAGE
6 3087998 Pad, Adjusting, 1.775 4 USAGE
6 3087999 Pad, Adjusting, 1.800 4 USAGE
6 3088000 Pad, Adjusting, 1.825 4 USAGE
6 3088001 Pad, Adjusting, 1.850 4 USAGE
6 3088002 Pad, Adjusting, 1.875 4 USAGE
6 3088003 Pad, Adjusting, 1.900 4 USAGE
6 3088004 Pad, Adjusting, 1.925 4 USAGE
6 3088005 Pad, Adjusting, 1.950 4 USAGE
6 3088006 Pad, Adjusting, 1.975 4 USAGE
6 3088007 Pad, Adjusting, 2.000 4 USAGE
6 3088008 Pad, Adjusting, 2.025 4 USAGE
6 3088009 Pad, Adjusting, 2.050 4 USAGE
6 3088010 Pad, Adjusting, 2.075 4 USAGE
6 3088011 Pad, Adjusting, 2.100 4 USAGE
6 3088012 Pad, Adjusting, 2.125 4 USAGE
6 3088013 Pad, Adjusting, 2.150 4 USAGE
6 3088014 Pad, Adjusting, 2.200 4 USAGE
6 3088015 Pad, Adjusting, 2.250 4 USAGE
6 3088016 Pad, Adjusting, 2.300 4 USAGE
6 3087988 Pad, Adjusting, 1.450 4 USAGE
6 3087989 Pad, Adjusting, 1.500 4 USAGE
6 3087990 Pad, Adjusting, 1.550 4 USAGE
6 3087991 Pad, Adjusting, 1.600 4 USAGE
6 3087992 Pad, Adjusting, 1.625 4 USAGE
6 3087993 Pad, Adjusting, 1.650 4 USAGE
6 3087994 Pad, Adjusting, 1.675 4 USAGE
6 3087995 Pad, Adjusting, 1.700 4 USAGE
6 3087996 Pad, Adjusting, 1.725 4 USAGE
6 3087997 Pad, Adjusting, 1.750 4 USAGE
6 3087998 Pad, Adjusting, 1.775 4 USAGE
6 3087999 Pad, Adjusting, 1.800 4 USAGE
6 3088000 Pad, Adjusting, 1.825 4 USAGE
6 3088001 Pad, Adjusting, 1.850 4 USAGE
6 3088002 Pad, Adjusting, 1.875 4 USAGE
6 3088003 Pad, Adjusting, 1.900 4 USAGE
6 3088004 Pad, Adjusting, 1.925 4 USAGE
6 3088005 Pad, Adjusting, 1.950 4 USAGE
6 3088006 Pad, Adjusting, 1.975 4 USAGE
6 3088007 Pad, Adjusting, 2.000 4 USAGE
6 3088008 Pad, Adjusting, 2.025 4 USAGE
6 3088009 Pad, Adjusting, 2.050 4 USAGE
6 3088010 Pad, Adjusting, 2.075 4 USAGE
6 3088011 Pad, Adjusting, 2.100 4 USAGE
6 3088012 Pad, Adjusting, 2.125 4 USAGE
6 3088013 Pad, Adjusting, 2.150 4 USAGE
6 3088014 Pad, Adjusting, 2.200 4 USAGE
6 3088015 Pad, Adjusting, 2.250 4 USAGE
6 3088016 Pad, Adjusting, 2.300
 

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Polman - you have it right - and adjusting the valves is critical - my CRF adjusts the same way

OP - all you need to do is measure the clearance, remove the cams, remove each lifter, inspect and/or measure the shim (size is usually laser etched with the size, but it's not always legible on a used shim) record the shim size currently in the machine (do not mix up the lifter buckets and shims), subtract the desired clearance, install the calculated shim size, install the cams & torque the holder, recheck the clearance - if correct, the job is done - if not repeat operation until valve clearance is correct. The service manual has a handy chart displaying shim selection.

This operation needs to be performed periodically (routinely) - since I replaced the titanium valves with stainless steel valves in my CRF, I only have to check the clearance twice a year and adjust them about once a year. I believe the Predator engine (which is high performance, but not a race engine) has steel intake valves as they only cost $29 ea in the Predator and $65 ea for the Ti valves in the Honda.

Normally I chastise owners for not reading their owners manuals and having the periodic maintenance performed, but I just read the owners manual and the service manual for the 04 Predator. If there is any reference to periodic valve adjustment I would like someone to point it out to me. I did not find it. For this reason, I sympathize with the OP, but valve clearance is critical for cold starting and needs to be maintained.

A shim kit is about $800 for 5 shims of each thickness. 6 kits are currently available; 7.5mm, 9.5mm, 13mm, 25mm, 29mm and 29.5mm diameters - I have all but 13 & 29.5mm - I have not yet had to work on an engine with those sizes, but factory shims may be of any thickness. i.e. aftermarket shims are typically available in .05mm increments (1.50, 1.55,1.60 etc) - factory shims are available in .01mm increments (1.55, 1.56, 1.57 etc)

Shops invest in things like shim kits so they don't have to order shims 'as needed'. Individual shims from Polaris are $14 to $17 each - on the after market they are less than $4 each. I don't concern myself with what diameter I need - I find out when I take one out and then just grab the kit I need. Certain Honda's have 7.5 on one side and 9.5 on the other side. Very handy!

It might be cheaper to take the vehicle to a dealer or repair shop to get the valves adjusted - some shops (like mine) don't charge for the shims, just exchange them. The only time I charge for shims is when someone just wants the shims and does not bring in their vehicle for service.
 

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Yeah I knew the Honda crf's were that way but the boys around here either don't adjust or take them to the dealer because they haven't brought any to me lol.
 

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Discussion Starter #10
Well i have another question aswell for some reason when I went through my carburetor and put the new choke cable and cleaned it it developed this high idle problem. It happens randomly but quite often it just revs up out of nowhere it's not sticking either anybody know what it could be?
 

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you did a compression test? b4 ring replacement? hand over cab is a force chock. will it run after getting it started? drivable? after hand chock? if so you may still have a carb prob

there is a problum with the cam lob in the 500's on the exhaust side you may need to look into the cam.. the exhaust lob will round out. Symptoms of bad cam exhaust lob...

starts but has no power/loss power
hard start back fire..boog
when bad you would think its a carb problem. starts but rev ends in a stall out... or a bogged down feeling..
with all the work you did it opens more options.. so we need to go back to the first prob and work forward..
 

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Just for everyones info the predator uses the same shims as the honda trx450. So you can buy the Hotcams valve shim kit anywhere online for around 50.00 bucks.
 
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