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Hole in outside of Rmx cynidler

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I have an 89 Rmx with a jug from a 94 model. I noticed today it has a hole on the side of the jug that exhaust is coming out of. It's a hole from the factory but has not theards. I'm having a hard time getting it started and I'm thinking it leaning out from this hole maybe.... anyone know what is suppose to be there?

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I have an 89 Rmx with a jug from a 94 model. I noticed today it has a hole on the side of the jug that exhaust is coming out of. It's a hole from the factory but has not theards. I'm having a hard time getting it started and I'm thinking it leaning out from this hole maybe.... anyone know what is suppose to be there?

A picture would help. But I imagine it is the power valve breather and the fitting the hose goes on has fallen out. But that's probably not your problem. Have you checked the compression with a gauge?

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Post a picture.  Or compare it to this exploded view of a '94 RMX cylinder:

 

2003_1.gif

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Thanks for the diagram. That helps. It the the hole above the power valves. So I guess I'm missing the fitting and the hose. As far as the compression I haven't checked it but there is no need to. I just built it 38 miles ago with a 2mm over bore Wiseco piston. It take a million kicks to start sometimes.... After its warmed up it fires right up. One kick. I just don't get it. I've tuned and tuned and tuned. I had a 60 pilot jet in it and I said well there's my problem put a 45 and put it in there and same deal with it starting but it definitely runs better. In fact it runs great! Idk where the needle should be but I moved it up 23 of the way on the screw out adjustment and it runs great. It had a bad studder with needle all the way down

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Hose #24 is just a breather, it routes to just below the engine cases and is open to the air.  Also, you really shouldn't be getting any exhaust out that hose (port), if you are then that's a sign that you need to inspect your power valve assembly.  Also, the RMX carbs were never that great, they were adapted from the RM's and the needs of a MX carb did not cover the needs of a endure carb.  That said, compare your jetting to what FMF or the factory posted and go from there.  Not sure if that'll fix your cold start issue but it's a start.

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Ok did a Compression check and it's only at 135ish.... shoukd be alot higher I think with the recent build I did. Wierd thing is the gauge didn't go up every kick.. only every couple of kicks. I have carb off and it is pushing alot of air out of the reed cage. Is this normal? Reed were recently replaced by previous owner with boyeson reeds. I took the out and they looked ok except there weren't setting flush

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yeah, compression is low. head gasket/o-ring isn't seated right ? I was also going to suggest air leaks, i.e. crankshaft seals, base gasket, crankcase gasket, read gaskets, etc... 

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I thought compression was way lower than it should be for a fresh build with a 2mm overbore and a thinner head gasket than stock but..... it should still start easy...

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Was the bore fresh or did you just put a new piston in the old overbore? Also did you have the throttle wide open when you comp checked it? Just dumping a new piston in a worn out cylinder will make it hard start cold, easier once things get up to operating temp and expand. Dont ask how I know....Did you check ring end gap, bore taper, etc.? It will also rapidly decline in the hot start ease once the top end "breaks in". In fact the more I read your posts the more I'm pretty sure you have a new piston in a worn cylinder, in which case tuning it properly will be impossible, and you run the risk of a broken piston ruining your bottom end as well.

Edited by ickfinger

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