[Spockster]

Yes the shipping is going to sting.

Arctic Cat and Harley have the same carb. Should be able to find jets below $10 each pretty easily, haven't looked for a while.

Stock jets? Maybe someone here has a pair?

yes stock jets and the carb rebuild kit i ordered dont have them in it. Typical. 62 euro from the netherlands for the 2 of them. 😲. I might check for harley ones. Might be easier to get. Is there a specific model i should search?

Pretty sure Sportster used this carb. Go by our carb model. CVK36 or CVK38, double check me on that.

Can also look for biggest Arctic Cat in the final years to have a carb. Snowmobile or ATV.

There's also websites dedicated to the CVK carb.

 

[Will750]

Ok thank you spockster i will check it out

 

[Will750]

Ok so recent update:
Lots done to find the problem. Carbs rebuilt. All new gaskets, jets etc.
Compression check: Ok
Fuel tap rebuilt.
New plugs.
Valve check: Problem with front cylinder.
So far this is what was wrong. Opened the cylinder cover and cam cover. Took off the tensioners and removed cams. ( making sure it was tdc and marks aligned. (Turned engine by hand)
2 of the cam guides that sit on the lash adjusters had fallen off. It must have happened when i put the cams on the first time without me realising. So spockster you were right about the valves.
I have yet to fire it up as it was late last night when i finished putting it back together. The whole procedure was done with the engine on the bike. Took about an hour in total. I will post the outcome later.

 

[Spockster]

Thanks for the update. So you were able to pull the valve covers without pulling the engine.. Always thought that might be possible, but never confirmed it.

 

[Will750]

Thanks for the update. So you were able to pull the valve covers without pulling the engine.. Always thought that might be possible, but never confirmed it.

Yes only on the front. Was a bit tricky but i managed it. So went to start the bike today after work and nothing. Eventualy got it to run with a shot of starter fluid. It idled great on both cylinders but i was still not able to rev past 2k or it would bog and die. Lots of popping and backfiring. I wonder would it have anything to do with the exhaust system maybe? I have the gb removed so pipes are just straight from the head to the rear mufflers. Its all i can think of as im out of options. I think its time to bin this engine and try and find a replacment as my paitence have worn out with this one. Any last ideas before she goes for the scrap heap?

 

[Spockster]

If you use the choke while trying to rev it up, what does it do?

 

[Will750]

If you use the choke while trying to rev it up, what does it do?

the exact same thing. If i give it choke once it idles for a bit it will try to cut out

 

[Spockster]

It's still popping after putting the rockers back in place?

Any chance they could have fallen off again?

Did it pop out of the exhaust, intake, or both?

 

[Will750]

It's still popping after putting the rockers back in place?

Any chance they could have fallen off again?

Did it pop out of the exhaust, intake, or both?

yup still popping and backfiring. Even harder to start now. Im starting to think my timing might be off some how. Altho i made sure it was 305*. It has to be either timing or carbs. I will check the timing over the weekend

 

[Spockster]

Could you tell where it's popping from? Intake, exhaust, or both?

 

[Will750]

Could you tell where it's popping from? Intake, exhaust, or both?

just the exhaust this time around. Got something in mind?

 

[Spockster]

Just still wondering if the valves are right. The cam guides that fell off... The spring steel tabs that ride on the rocker arms? Kawi may refer to them as cam followers instead of rocker arms.


Not sure which part fell out of place, the rocker arms or the spring steel tabs.

 

[Will750]

Just still wondering if the valves are right. The cam guides that fell off... The spring steel tabs that ride on the rocker arms? Kawi may refer to them as cam followers instead of rocker arms.


Not sure which part fell out of place, the rocker arms or the spring steel tabs.

Sorry i should have been more clear. It was the rocker arms not the spring steel tabs. I deffo think it must be timing.

 

[Will750]

Ok so i found a small problem with the timing marks. I took off the front head cam cover to check alignment with the mark on the rotor. When i rotate the rotor to align with the mark on the outside of the rotor cover the 2 marks on the cams seem to be off a tad bit. One seems to be up a little while the other is down. From what i can see it looks to be off by one tooth. To give an idea of what i mean, if i turn the rotor an extra little bit to align the cam marks evenly with the head, the rotor cover mark is at the F instead of being at the line on the rotor before the TF.
I was able to lift the rear cam cover just enough to conform that all marks line up perfectly with the head surface and rotor marks.
Could this be the cause of my headache these past few weeks.
Would being out one tooth cause a no rev and hard start situation?

 

[Spockster]

Yes it can. Alignment has to be precise, the smallest opening of a valve at the wrong time means combustion goes past the valve and produces no power, but probably a backfire.

Same timing applies to the ignition, late or early spark usually kills power.

 

[Will750]

Yes it can. Alignment has to be precise, the smallest opening of a valve at the wrong time means combustion goes past the valve and produces no power, but probably a backfire.

Same timing applies to the ignition, late or early spark usually kills power.

ok. i am hoping to get it sorted tomorrow so i will post the results once i have them.

 

[Will750]

Ok so sorted the timing issue. Started fine, idled fine but still wont rev passed 2k. Pulled the carbs again, cleaned and made sure nothing was blocked. Sprayed cleaner in every hole until it came out somewhere else. Plugs are black with carbon. Also popping out of the front carb again. Also blowing a bit of gas and smoke out of the front carb also. Also when i turn the engine by hand i can hear air being forced out from what i think is the exhaust. Is that normal?.Im so sick of trying to fix this bike im thinking of just parting it out

 

[Spockster]

It's normal to hear some hissing when turning by hand. It's compression in the cylinders.

Might need a leakdown test to see if any valves are leaking. Maybe a compression test too.

 

[Will750]

It's normal to hear some hissing when turning by hand. It's compression in the cylinders.

Might need a leakdown test to see if any valves are leaking. Maybe a compression test too.

im midway pulling the engine AGAIN. Going to pull the heads and check the valves,maybe even reseat them. Im thinking of getting a rebore and new piston aswell. Im determend to get this bike going. I will keep updating as i go.

 

[Will750]

UPDATE
Got the motor out and pulled the front head off to check the valves. Iv taken out the 2 intake valves and one of them is hard the get in and out of the guides. I got to push it in kinda harder than normal. Its the same on the other guide aswell. The other valve slides in and out with ease in both valve guides as it should. It doesnt look bent at all. Im thinking of replacing it anyway just out good mesure. Also when i pulled the head off there was a good amount of oil on the piston and intake valves. Any ideas what could cause this?