Honda Spree and Elite 50 Forums

I'll see what my compression is tomorrow and install my wideband o2 while I'm at it. I'll let you know what i find.

Didnt get time to do the wideband install but got a new compression gauge and i think i found my problem. Dont have the electric starter hooked up, Im almost at 200psi, tried it quite a few times, right around 200, guess ill be making a thicker head gasket.

Greetings:

Thanks for sharing. Hollowing out the head for a few cc's worth of metal shaved is another option to a double-or triple-thick head gasket. The base stack should result in the piston crown clearing the bottom of all the ports at BDC, then adjust compression as above. If you drag-race on pump Premium, 135 may be OK. For a daily rider, shoot for around 120.

I could hollow out the head but it wouldnt be pretty, i figured making a thicker gasket would be the better option.

you can buy the thicker paper gasket material from cragen or schucks for the base and you can use 2 head gaskets.yes around 120psi will be the area you want to shoot for.

cut the head only if you have a metal lathe and cut the squish band the same angle if possible. you will also have to open the combustion chamber too,the combustion chamber should 50% of the bore size and the squish should be 25% of the combustion chamber. so the combustion chamber on your 51mm bore will be 25.5mm in diameter and the squish wil be 12.75mm at a 14 or 15deg angle.measure the cc of the combustion chamber so you know how deep you have to cut in. if you going to cut it by hand,expect to have tunning issues or it blowing up.

Got compression down to around 115ish. Still seems to be running hot. Head temp got around 300 and it's still running rich. Have a 105 main jet in there and with my wideband I'm still seeing around a 11.5 afr.

Paul604 wrote:Got compression down to around 115ish. Still seems to be running hot. Head temp got around 300 and it's still running rich. Have a 105 main jet in there and with my wideband I'm still seeing around a 11.5 afr.

the 300deg is pretty good. remember this is a aircooled 2 stroke not waterccoled 4 stroke. the 11.5to1 air/fuel ratio is rich. ideal is 14.5to1 so around 12.5 to 13.5 to1 is really good both for cars and 2 stroke engines. do you have larger jets than 105? are you also premixing some?

300 degrees was after a short 10 min ride. No hills part throttle. I have up to a 120 main. I'm going to lean it out a bit more. Try to get it around 12.5 afr. Just don't want to overheat it again. Shouldn't it run cooler being so rich? I'm premixed at 32:1 with 94 octane.

up your oil to fuel ratio to like 28to1. 300 deg is good for a cast iron bore. are located in the US? is that race gas or pump gas? if your still using the stock carb,switch to a larger carb like a 24 or 28mm carb.the pilot on the stock carb is way to small and you can seize that setup quick if you let off from wot to closed throttle.

I'm in Vancouver canada. I'll try adding a bit of oil. Gonna get another new plug. Running a bpr8hs right now. Stock carb was a 16mm. Switched to a 19mm keihin. Pilot is a 42 right now. 94 octane pump gas. I can get race gas but I'd rather run pump I think.

Paul604 wrote:I'm in Vancouver canada. I'll try adding a bit of oil. Gonna get another new plug. Running a bpr8hs right now. Stock carb was a 16mm. Switched to a 19mm keihin. Pilot is a 42 right now. 94 octane pump gas. I can get race gas but I'd rather run pump I think.

the pump gas will be fine since you lowered the compression.canada uses a different octane rating system so thats about 91or92 octane here in the states. are you using the stock airbox or pod filter?try a b8hs or br8hs plug.

Running a small cone filter right now. Ill get the jetting right and see what kinda temps I'm at

you might have to play with the pilot too if your getting heat spikes on off throttle.if your getting a slight bogg when you get off the throttle then get back on it then the pilot is too small yet.if you don't have pilots to play with,you can oil the filter if it doesn't already have oil on it.

Just got home from work and swapped in my 42 pilot, and a 89 main, feels really good, ill check the afr tomorrow. Took it out for a good ride, max temps i hit were 275ish

Have to check for leaks, my afr isnt right. Its roughly around 13.5-14 right now which should be quite lean. Rode around quite a bit today and temps are maxing out at 300. Gonna ride it to work tonight and see how it is. Seems a lot slower than it was before when it was high compression but thats expected. Have to find out what the gearing is in the af24, im not getting much for top end. Maybe 40mph at most, doesnt seem right. Have 7g rollers in there now, maybe i have to try some heavier ones? Im like 6'3 250lbs though so im not sure what ill need to do in the way of rollers.