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Apex engine gurus... Help needed...


Thanks again for the additional feedback! I hope everyone had a happy holiday weekend! I finally got back around to getting an update on where I am at. Over the weekend, I got the following items completed. Performed a compression check and didn't find anything out of the the ordinary ~190 psi +/- 10 psi. Plugs all looked about the same, the only thing I noted was that they seem to be awfully dark in color. I would expect that they would have been burning a little cleaner... Any comments on this? I replaced them with new EK plugs because I had them on hand already and took particular time to gap them to .029". So is this the current consensus that the EK plugs are no longer the thing to do when they were all the rage a couple of years ago???

I also confirmed the fuel pressure. That all checked out pretty decent. Fuel pressure was at about ~40 psi on my gauge and didn't fluctuate at all all the way through the powerband, so that looks to be working correctly, but this is with no load of course. Too bad there isn't a way to check the injectors...

Sooo, no smoking gun from the engine as of now. Based on the overwhelming feedback I have gotten so far, it looks like I should re-evaluate my exhaust situation and look into diverting the exhaust outlet out the side of the tunnel.

I am also going to walk through the service manual procedure and check out the stator.

I'm still not conviced about the engine though and I would still like a dyno run for a little bit of peace of mind, and I may still do this especially to see in a controlled environment what this thing is doing under a load... I've spend more money on dumber things... I'll keep you posted...

I also think I will have to consider reviewing my clutching situation as well because I am sure that it is not quite right either, but one thing at a time for now... :)

I forgot to bring my "custom" clutching spec sheet this morning so I could at least let you know where my setup is at to give you an idea of my baseline and how far off it may be... :( I'll get that up in the next post. What I can remember off hand is I am using 89A weights, 14.5 rollers and supposed to be swinging like 54.6 grams with the Y-P-Y spring, and I am actually down to closer to about 50 grams to get the thing to rev... TEAM Secondary is something like a 48-32 helix with the red-black spring, and 19 tooth top gear and stock drivers.
 
i suspect clutching - i'd verify all the parts in the secondary are healthy - i would check the spring and if that appears correct check the proper twist - sounds like the belt is getting burried in the secondary prematurely.
 
I think I found something!!!

I checked the stator last night! Here is what I found... This was all done with a calibrated Fluke meter...

Stator coil spec is .19-.24 ohms.
Mine tested at .3-.4 ohms.

Here is the big one though!

Pickup coil spec is 189-231 ohms.
Mine tested at 501.8 repeatedly!!!

Did I find the root of my headaches?!?!?

steve 05 RX-1, can you provide further elaboration as it sounds like you have had experience with this failure???

I'm kinda excited now!
 
My pickup coil failed completly on the yamaha, no warning. Its fairly common, only ever seen/heard the pickup coil go bad.Ive seen other sleds with rpms falling turn out to be stator, thats how I made my guess by symptoms.
 
Re: I think I found something!!!

Theicor said:
I checked the stator last night! Here is what I found... This was all done with a calibrated Fluke meter...

Stator coil spec is .19-.24 ohms.
Mine tested at .3-.4 ohms.

Here is the big one though!

Pickup coil spec is 189-231 ohms.
Mine tested at 501.8 repeatedly!!!

Did I find the root of my headaches?!?!?

steve 05 RX-1, can you provide further elaboration as it sounds like you have had experience with this failure???

I'm kinda excited now!

500 ohms is normal for the apex pickup coil
 
When my stator was shot in my old apex it was reading 38000 ohms. The working stator I put back in was reading 502 ohms. So I don't know if that is your problem. I suspect clutching and exhaust combined as the problem. Check the spring wind of your secondary.
 
Seriously??? WTF??? I give up... :o| 500 ohms is good? We'll have to see... Probably another $300 pizzed away...

2006 Apex Mtn for sale... :o|

The Stator should be coming in this week sometime and I should get that in early next week. I have been thinking lately as I have been waiting for the stator to arrive. Where do I begin with the clutching? Should I start over with the bone stock clutching? I don't know if that will work so well with the different gearing and etc... Should I start off with the "custom" setup??? Here is that setup... Y-P-Y spring, 14.5 rollers, 89A-10 Weights, 10.3 inner, 13.3 outer, 54.6 grams. Recommended secondary setting for the team is a 58-42 with the red-black spring. Gearing is at 19-40... I'm kinda thinking a combination of both, custom primary with the stock secondary... But that is just one idea, I guess I've never been overly impressed with the stock setup, but I am open to suggestions... Thanks everyone, I'll keep you posted!

Corey
 
Start with stock , make it run right , only then add clutching. Your secondary is set up wrong from the info.

Stator is not the issue.

For clutching call Allen Ulmer !
 
I agree get that exhaust out of there and get the clutching back to stock. There is nothing wrong with the stock clutching. Make sure the sled works then start changing and modding.

Your pissing into the wind 'trying' different clutching with no ryme or reason. Be more methodical about it and your baseline is stock.

I"ll buy your sled if going back to stock doesn't fix it :)
 
I would run a line to the airbox and when it wogs out, give it a little squirtsville of carb cleaner to see if it picks up. sounds like fuel blockage or water. could also run clear line from return to a can and see if it is returning when wogging out
 


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