300cc tuning and performance - Page 2

kilo0195 · 09-18-2017, 09:38 PM

So I'm @ 2300 miles on the build now. Still ride it like I stole it. Think I'm going to be replacing a clutch this winter. It's starting to chatter a little in neutral until I pull the clutch lever in. Granted with the way I've been riding it I'm surprised that's the only problem.

Vegas Street Rider · 09-19-2017, 01:31 AM

Stay safe.

kilo0195 · 09-22-2017, 04:35 PM

Will do. Just really wanted to see what I could do to and with this bike without it just giving out. I must say I'm impressed so far for a "250" thumper. I'm really considering getting an s40/ls650 thumper at this rate and tweaking it.

kilo0195 · 11-20-2017, 09:55 PM

Quick note... I posted a question on a new thread wondering if a 90-95 dr250 cam would fit. It will and is profiled to give more power. I've found a shop that grinding a one off cam for my bike and is also going to send me some titanium retainers and double sprung valve springs. Once the head is off I may deck it a little more to bump the CR if clearance will allow. As far as my clutch, I may look into seeing if I can fit an extra disc, or if there is a better clutch pack that will fit this bike. I'm really hoping that the new cam will help my acceleration on the highway. Accelerating while I'm cruising at 75-80 can be a little slower than I like right now with a final drive of 2.41. Will update after I get the cam and install it.

kilo0195 · 11-27-2017, 10:18 PM

Few other updates I forgot. I definitely use more oil now. I went thru a 1/2 quart in about 1000 miles. Compression is good, no oil on the plug, etc. Not sure if it's that I'm riding her harder now that she can perform or if it's a difference in piston design. I also had changed from the 17t front to aluminum 16t front a d 39t rear... effectively changing final drive from 2.41 to 2.43. I ditched the o-ring chain and am running a non o ring chain. More maintenance but I'm always jacking with it so no big deal, and I'd rather have the extra torque to the wheel. The sprockets and chain have made a decently noticeable difference on how well she takes off from a stop. I will also be changing the clutch to Kevlar plates and heavier springs. Since the build I've glazed the stock discs which is allowing it to slip under hard throttle even when not shifting... gotta love cork and rubber lol. I've sent an extra cam I had off to the shop and am waiting to hear back.

Water Warrior 2 · 11-28-2017, 06:55 AM

What weight and brand of oil are you using?

kilo0195 · 12-11-2017, 10:00 AM

Castrol Power1 synthetic 10w40.

kilo0195 · 12-17-2017, 07:47 PM

The Kevlar clutch and stiffer springs from Barnett are a nice upgrade. I actually stalled it leaving the driveway because I had gotten used to how much the cork and rubber slipped. Only complaint would be that holding the clutch in at lights can be a little tiring on the hand now, especially because shifting to neutral is damn near impossible when it's running (always been that way). Anyways I got what I was after which was to eliminate any slipping under hard acceleration. The cam should be here in about 2-3 weeks. In talking with the shop we've gone with a profile somewhere just above a stage1 or mild cam. Anything more and I'd have to greatly increase compression, more so than just the deck job I've got. It would entail finding another shop to make a custom high compression piston that frankly I don't feel like spending that much money on. The whole bike so far has been dirt cheap to mod, and I'd be spending close to what I've put into the bike total just for the piston. The cam profile will add .070 lift and much more duration and ramp speed. Sorry I'm not allowed to share the exact specs of the cam. Anyways, sometime shortly after the new year I should have the cam installed and be able to give some details as to it's improvements.

kilo0195 · 01-11-2018, 06:15 PM

Cam arrives tomorrow... I'm a bit excited! Over Christmas break I had her on a dyno and got a hp and air/fuel reading. They couldn't get a good rpm signal (some sort of interference) so there was no way for them to get a reliable torque reading. I was putting 21hp to the wheel which isn't too bad considering my 2.43 final drive and wide heavy tire I'm running. Besides I've seen a stock Buell blast 500cc dyno at 22.5whp. He also had dyno tuned a couple gz's in the past for customers and said they were in the 14 to 14.5whp range when done. I really would like to address the tach problem to get a good torque reading but that's a different story. Air fuel mix was ungodfully rich until I hit wide open throttle so she is way out of tune and I could possibly pick up a little more power with a good tune. I will correct that after the cam swap. For the swap I will be removing the head and the jug as well. The head I plan to clean up the port job on it and the jug will be sent to be decked. How much I can deck will have to be determined especially as the head already has .040 or .045 shaved off. I hope to be able to get at least .045 off the jug as I was advised the higher cr I can get the better the cam will perform. This will also give me a good look at the piston and cylinder walls to see how things are holding up. It sucks she'll be down for a while, but I can't wait to see the difference.

Water Warrior 2 · 01-12-2018, 01:40 AM

Impressive numbers. Your mods will keep you fixing the weakest link as time goes by. Not a bad thing if you want some fun and can afford to keep repairing the bike.
Carry on and keep us in the loop.

09-18-2017, 09:38 PM	#11
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	So I'm @ 2300 miles on the build now. Still ride it like I stole it. Think I'm going to be replacing a clutch this winter. It's starting to chatter a little in neutral until I pull the clutch lever in. Granted with the way I've been riding it I'm surprised that's the only problem. Login or Register to Remove Ads
	0

09-22-2017, 04:35 PM	#13
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	Will do. Just really wanted to see what I could do to and with this bike without it just giving out. I must say I'm impressed so far for a "250" thumper. I'm really considering getting an s40/ls650 thumper at this rate and tweaking it. Login or Register to Remove Ads
	0

11-27-2017, 10:18 PM	#15
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	Few other updates I forgot. I definitely use more oil now. I went thru a 1/2 quart in about 1000 miles. Compression is good, no oil on the plug, etc. Not sure if it's that I'm riding her harder now that she can perform or if it's a difference in piston design. I also had changed from the 17t front to aluminum 16t front a d 39t rear... effectively changing final drive from 2.41 to 2.43. I ditched the o-ring chain and am running a non o ring chain. More maintenance but I'm always jacking with it so no big deal, and I'd rather have the extra torque to the wheel. The sprockets and chain have made a decently noticeable difference on how well she takes off from a stop. I will also be changing the clutch to Kevlar plates and heavier springs. Since the build I've glazed the stock discs which is allowing it to slip under hard throttle even when not shifting... gotta love cork and rubber lol. I've sent an extra cam I had off to the shop and am waiting to hear back. Login or Register to Remove Ads
	0

09-19-2017, 01:31 AM	#12
Vegas Street Rider Senior Member Join Date: May 2015 Location: Henderson, NV Posts: 1,105	Stay safe.
	0

11-20-2017, 09:55 PM	#14
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	Quick note... I posted a question on a new thread wondering if a 90-95 dr250 cam would fit. It will and is profiled to give more power. I've found a shop that grinding a one off cam for my bike and is also going to send me some titanium retainers and double sprung valve springs. Once the head is off I may deck it a little more to bump the CR if clearance will allow. As far as my clutch, I may look into seeing if I can fit an extra disc, or if there is a better clutch pack that will fit this bike. I'm really hoping that the new cam will help my acceleration on the highway. Accelerating while I'm cruising at 75-80 can be a little slower than I like right now with a final drive of 2.41. Will update after I get the cam and install it.
	0

11-28-2017, 06:55 AM	#16
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	What weight and brand of oil are you using?
	0

12-11-2017, 10:00 AM	#17
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	Castrol Power1 synthetic 10w40.
	1

12-17-2017, 07:47 PM	#18
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	The Kevlar clutch and stiffer springs from Barnett are a nice upgrade. I actually stalled it leaving the driveway because I had gotten used to how much the cork and rubber slipped. Only complaint would be that holding the clutch in at lights can be a little tiring on the hand now, especially because shifting to neutral is damn near impossible when it's running (always been that way). Anyways I got what I was after which was to eliminate any slipping under hard acceleration. The cam should be here in about 2-3 weeks. In talking with the shop we've gone with a profile somewhere just above a stage1 or mild cam. Anything more and I'd have to greatly increase compression, more so than just the deck job I've got. It would entail finding another shop to make a custom high compression piston that frankly I don't feel like spending that much money on. The whole bike so far has been dirt cheap to mod, and I'd be spending close to what I've put into the bike total just for the piston. The cam profile will add .070 lift and much more duration and ramp speed. Sorry I'm not allowed to share the exact specs of the cam. Anyways, sometime shortly after the new year I should have the cam installed and be able to give some details as to it's improvements.
	1

01-11-2018, 06:15 PM	#19
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	Cam arrives tomorrow... I'm a bit excited! Over Christmas break I had her on a dyno and got a hp and air/fuel reading. They couldn't get a good rpm signal (some sort of interference) so there was no way for them to get a reliable torque reading. I was putting 21hp to the wheel which isn't too bad considering my 2.43 final drive and wide heavy tire I'm running. Besides I've seen a stock Buell blast 500cc dyno at 22.5whp. He also had dyno tuned a couple gz's in the past for customers and said they were in the 14 to 14.5whp range when done. I really would like to address the tach problem to get a good torque reading but that's a different story. Air fuel mix was ungodfully rich until I hit wide open throttle so she is way out of tune and I could possibly pick up a little more power with a good tune. I will correct that after the cam swap. For the swap I will be removing the head and the jug as well. The head I plan to clean up the port job on it and the jug will be sent to be decked. How much I can deck will have to be determined especially as the head already has .040 or .045 shaved off. I hope to be able to get at least .045 off the jug as I was advised the higher cr I can get the better the cam will perform. This will also give me a good look at the piston and cylinder walls to see how things are holding up. It sucks she'll be down for a while, but I can't wait to see the difference.
	0

01-12-2018, 01:40 AM	#20
Water Warrior 2 Senior Member Join Date: Dec 2006 Location: Squamish B.C Canada Posts: 11,409	Impressive numbers. Your mods will keep you fixing the weakest link as time goes by. Not a bad thing if you want some fun and can afford to keep repairing the bike. Carry on and keep us in the loop.
	2