Why do I bother taking my bike for routine maintenance? :banghead:

2006 Husqvarna smr510
JD jet kit:
Red needle 5th clip i think
180 main
leak jet provided with kit
45 pilot
thick oring
Akrapovic full ti

i jetted and piped that thing when i got it and i had it dialed in almost perfectly. put off having recommended valve check because it always ran so great. within the last year the popping on decel got pretty bad so i figured i should mess with my jetting now that the motor has broken in. i dropped it at a local shop to have valves checked and mount tires. figured while it was there they could see if they could get rid of decel pop. figured i might have to go up one on pilot jet. anyhow when i went to pick the bike up it was hardly running. goose the throttle and it pops, blows flames and stalls. (never did that before) they said they didn't touch anything except my fuel mixture screw. they said they checked valves and they were perfect so no adjusting. spent five hours at the shop ripping carb apart and checking everything. still didn't fix it. at the end of five hours they think that the rubber manifold is sucking air right where it bolts up to the head. i'm gonna now order that and hope that's what it is, but i have a feeling that's not it. pretty pissed off that my bike was running so good and now after routine maintenance i can't even ride.

any thoughts?

rover7 said:

Airleak sounds plausable:
Let bike warm up- if it idles fine- check for air leaks around carb by spraying WD40 or something at the air bell and manifold- push on the carb lightly- if the idle changes look fourther for leaks. Check that the crank case vent is hooked up to the manifold and has no leaks- or if (was rerouted to a separate filter (after market) make sure that the manifold is still capped/sealed).

Make sure pilot jet is not clogged and make sure the fuel screw has the spring, washer, and oring. Verify how many turns out you have.

Also check that you have

DRZnXJnWI said:

thanks,
spraying around carb was one of the first things these guys did and we didn't notice any leaks. however the bike was idling fine and i'm wondering if the air is getting in that manifold only when throttle is cracked open and the carb and rubber manifold move. the rubber manifold where it mounts up to the engine can be pealed back and it does look like there may be some cracks where the rubber and metal meet. i ordered this manifold and i am praying it is the weak link here. i'm just real frustrated that my bike ran damn near perfect before i dropped it off at the shop and now i can't even ride it.

what exactly is the crank case vent?

as far as fuel screw, that is an after market and it has spring, washer and oring. when bike was running great the fuel screw was basically all the way in and hence the first thing the shop tried screwing out a bit to help with my decel pop.

at this point i just want to get my bike running like it was and then i will worry about my decel pop

Check for an exhaust leak in regards to the decel popping. Either at the header/motor junction or header/midpipe section.

Tear the carb apart and inspect it. Look for loose and/or missing jets and make sure the o-ring is still on the fuel screw.

If the bike bike ran best with the fuel screw all the way in they you're too rich on the pilot jet. Lean it out one size and test. Fuel screw should lie somewhere between 1 and 2.5 turns out from fully seated (closed). If it runs better under 1 turn out then you're too rich. If it runs better at more than 2.5 turns out then you're too lean on the pilot circuit.

Pincushion said:

thanks guys,
right now i'm going to put off worrying about pop on decel and if i was running to rich or lean on pilot. i just wanna get this thing running again. what the hell could have happened in a couple of days sitting at the shop to make the thing run like crap off idle? i had that thing running off idle like a 2 stroke. it was so snappy. i'm hoping that this rubber manifold is leaking and that the new one on order fixes this issue. strange that it would just go when it was at the shop for a couple days.

could anything get knocked out of whack while doing just a valve check? this is the only thing that they really worked on and they said valves were in spec and they didn't need to adjust.

If it ran fine before they touched it, then whatever they touched is most likely the problem. If what they touched was valves, I would check em.

Sounds like they may not be telling you the whole story.

JustTroItIn said:

totally agree with you, but if they didn't adjust the valves is there any reason to think it has anything to do with them checking the valves? i haven't personally done a valve check, but from what i know, i believe they would have just taken valve cover off checked clearance and put valve cover back on. don't know if anything could get messed up in that process that would cause severe off idle issue of popping and stalling???

the only other thing they said they did was to turn fuel screw a little bit out to richen it up. we put fuel screw back in and no change to problem.

only thing we didn't do at the shop is take apart top of carb. maybe i should try that next?

The crankcase vent hose goes from the valvcover (the thing you take off to check valves) to the air manifold or airbell on yours. So that could have been disconected and not reconnected- causing an airleak (adding unmetered air to your fuel mixture)- this would also vent your motor to the atmosphere and air would be unfiltered and unprotected.

May not be the case but you should check- and know what the importance and function is of that hose- its significant.

DRZnXJnWI said:

wow that sounds like a very likely cause of this issue being that the valve check was the only major thing they did. i'm pretty familiar with the my bike but the crankcase vent hose is not something i am familiar with. will i see this hose coming off the top of the valve cover? is it easier to see from one side of the bike or the other?

thanks

rover7 said:

its on the right side of the valve cover- but make sure its a good seal on both ends. if you take the seat off its real easy to inspect by the air manifold- it looks like a 1/2" piece of auto heater hose.

does it start ok? if you have managed to run it enough to warm up, does it start the same when it is warmed up? any other plugs that could me missing, as in if you have plugged an emissions port?

motometal said:

it definitely doesn't start as easy as it did before this issue. before this issue all i did with a cold motor was choke it, give the throttle two whacks and hit the start button and it would start instantly.

i don't believe this new problem was any different while starting with a warmed up engine, but at this point i was so frustrated after 5 hours of sitting at the shop that i can't say for sure. i haven't had a chance to mess with it since saturday so i have to go back with a fresh head and see if i can find the cause. i really think it's something stupid causing this problem.

how much do you trust their word? Any chance they messed with the valves and they are now too tight? I doubt it but...

I"m guessing it is something they did to the bike that they don't think would cause a problem and/or "failed to mention" to you

motometal said:

at this point i have to trust their word. they worked on another bike of mine when i was ready to junk it because nobody else could fix the problem and they got it running like new and charged me less than quoted...so like i said i have to trust what they are telling me.

they insist that all they did as far as engine or carb was check valves which were fine and turn fuel screw out about one turn. now it's up to me to solve the riddle. i'm going to fill the tank up with fresh gas, check all hoses, install new rubber manifold when it arrives and hope that one of those things fixes my issue. if none of those things get my bike running back to the way it used to, then i suppose i will go back to ripping apart carb. my last resort would be to take it to a reputable husky dealer and see what they think. maybe have them check the valves.

in the middle of a long ride, I once had the pilot jet spontaneously plug up. The bike wouldn't idle and there was a lot of decel popping. I took the carb apart, no dirt in the bowl, I ran something through the pilot jet (but couldn't see any dirt), put it back together and it ran perfect again. It doesn't take much to plug the pilot jet.

motometal said:

cleaned the pilot jet out on saturday during my 5 hour vacation at the cycle shop. also cleaned and blew air through main, leak, accelerator pump...

Check the diaphram on the accelerator pump. Compressed air may have torn it or dislodged something. That circuit is delicate and finicky.

skydabber said:

yeah we checked the diaphram for tears also.

Success!!!

Well almost. I removed the old rubber manifold and it was shot! It was hard to tell just how bad it was when it was on the bike. When hitting the throttle the carb and manifold would move back and forth like a speaker cone. I thought this was normal. Once I put the new manifold on there was no movement.

And the most important part, was my issues went away. I can't imagine how much air was being sucked into the engine. Anywho, there is basically not decel pop and no flames or popping when revving the bike at a stand still. Unfortunately I now have to mess with my jetting now that everything is sealed up. I'm sure my jetting was on the rich side to compensate for all that extra air intake. I going to start by checking the AP squirt and probably go from my 45 pilot to a 42 as recommended in my JD jet kit. Surprisingly the bike doesn't run too bad, but I'm getting that bog and stalling when I crack the throttle. Hopefully nothing that a little jetting tinkering won't cure.

I'll keep you guys posted and thanks for all the help in figuring this one out.

Congrats!
Hey by the way didn't you say this shop took 5 hours and couldn't find the problem- I don't own a shop, but I don't think I would have given you the bike back like that for you to return it to diagnose. I would have called you and told you of the problem and had it fixed the first time. I don't think I would have missed this... Just saying-

I am happy you have it resolved- yes a 42 pilot sonds in order- if you have a JD kit just follow the recipe and go from there- I wouldn't blow air into the carb circuits anymore- you can take out jets and do whatever you want to them- let them soak overnight whatever- but be careful with that carb. :thumbsup: